university grants commission research project: by dr. b. n. kokare, raje ramrao mahavidyalaya, jath,...
TRANSCRIPT
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 1
Liquid anion-exchange extraction and separation of
precious metals by using High Molecular Weight
Amine (HMWA) as a metallurgical extractant.
MINOR RESEARCH PROJECT
FINIAL WORK DONE REPORT
(07-06-2014 to 06-06-2016)
Submitted to
UNIVERSITY GRANTS COMMISSION
WESTERN REGIONAL OFFICE, PUNE
By
Dr. Shrikant R. Kokare Dr. Balasaheb N. Kokare M. Sc., Ph. D. M. Sc., Ph. D.
Co- Investigator and Head Principal Investigator and Head,
Post Graduate Department of Physics, Post Graduate Department of Chemistry,
Raje Ramrao Mahavidyalaya, Jath
2017
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 2
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 3
INDEX
Sr.
No.
Details Page
No.
1 Audited Consolidated Statement of Expenditure with item wise
details under ‘non-recurring & ‘recurring’ heads for the amount
actually incurred duly signed by the Principal & C. A. with stamp &
Registration No. Annexure III (Annual)
2 Statement of Expenditure on Field Work in the prescribed
formats as per UGC guidelines. Annexure IV (Annual)
3 Audited Consolidated Utilization Certificate for the amount
actually incurred, duly signed by the Principal & C. A. with
stamp. Annexure V (Annual)
4 Annual Report of the work done of the Minor Research
Project. Annexure VI (Annual) and Appendix-I
5 Audited Consolidated Statement of Expenditure with item wise
details under ‘non-recurring & ‘recurring’ heads for the amount
actually incurred duly signed by the Principal & C. A. with stamp &
Registration No. Annexure III (Final)
6 Statement of Expenditure on Field Work in the prescribed
formats as per UGC guidelines. Annexure IV (Final)
7 Audited Consolidated Utilization Certificate for the amount
actually incurred, duly signed by the Principal & C. A. with
stamp. Annexure V (Final)
8 Certificate (Utilization of grant within tenure)
9 Accession Certificate (Books and Journal)
10 Assets Certificate (Equipments)
11 A copy of the proof about uploading of Executive summary of
the report, Research documents, monograph, papers published
under Minor Research Project on the website of the College
12 Final Report of the work done of the Minor Research Project.
Annexure VI (Final) and Appendix-II
13 Proforma for submission of information at the time of sending the
final report of the work done on the project Annexure VII (Final)
14 Work Done in the prescribed format Chapters I, II, III & IV
15 Publications
16 Acknowledgements
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 4
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 5
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 6
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 7
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 8
Appendix – I (Annual)
Report of the work done in First Year
Project Title : “Liquid anion-exchange extraction and separation of
precious metals by using High Molecular Weight Amine (HMWA)
as a metallurgical extractant”
1) In the first phase, reference work and literature survey on high molecular weight amine
and their synthesis is done. Chemicals, glass wares and equipments for project work are
purchased.
2) Synthesis of 4-Heptylaminopyridine (High Molecular Weight Amine)
To a stirred solution of 4-aminopyridine (0.05 mol) in dry THF (40 mL), sodium
amide was added at 0oC and continued stirring for 30 min. The temperature of the reaction
mixture increased to room temperature and 1-bromoheptane was added slowly. The reaction
mixture was stirred at the ambient temperature for 1 h. The reaction mixture was poured into
water containing NH4Cl and extracted with chloroform (150 mL). The chloroform extract
was dried (Na2SO4) and evaporated on a rotary evaporator to yield a residue which was
crystallized to afford the corresponding 4-heptylaminopyridine.
N
NH2
+ NaNH2
N
NH
+ NH3
Na
THF/ Stirr
0 oC
+
N
NH Na
StirrBr-CH2-(CH2)5-CH3
1 hr.
N
NH-CH2-(CH2)5-CH3
+ NaBr
3) 4-Heptylaminopyridine is white solid, which is readily soluble in xylene, toluene, benzene,
carbon tetrachloride, chloroform and acetone. Recrystallisation involves huge losses. We
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 9
recrystallised 4-heptylaminopyridine from acetone and obtained a product containing 99.9%
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 10
Annexure – III (Final)
UNIVERSITY GRANTS COMMISSION
BAHADUR SHAH ZAFAR MARG
NEW DELHI – 110 002
STATEMENT OF EXPENDITURE IN RESPECT OF MINOR RESEARCH
PROJECT
1. Name of Principal Investigator : Dr. B. N. Kokare
2. Department of PI : Chemistry
Name of College : Raje Ramrao Mahavidyalaya, Jath Dist-Sangli
3. UGC approval letter No. & date : No 47-601/13(WRO), date: 26 March 2014
4. Title of the Research Project : Liquid anion-exchange extraction and
separation of precious metals by using High
Molecular Weight Amine (HMWA) as a
metallurgical extractant
5. Effective date of starting the Project: 07-06-2014
6. a. Period of Expenditure : From 07-06-2014 to 06-06-2016
b. Details of Expenditure
Sr.
No.
Item Amount
Approved in Rs.
Expenditure
Incurred in Rs.
i Books and Journals 20000 20000
ii Equipment 250000 250000
iii Contingency 20000 20126
iv Field Work / Travel 25000 25358
v Special Need (Hiring Services,
Spectra analysis)
40000 40070
vi Chemicals and Glassware 80000 80100
Total 435000 435654
7. If as a result of check or audit objection some irregularly is noticed at later date,
action will be taken to refund, adjust or regularize the objected amounts.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 11
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 12
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 13
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 14
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 15
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 16
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 17
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 18
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 19
Annexure –VI Final
UNIVERSITY GRANTS COMMISSION
BAHADUR SHAH ZAFAR MARG
NEW DELHI – 110 002.
Final Report of the work done on the Minor Research Project
(Report to be submitted within 6 weeks after completion of each year)
1. Project Report No. 1st / Final : Final
2. UGC Reference No. F. : 47-601 / 13 (WRO), dated 26 March 2014
3. Period of report : from 07-06-2014 to 06-06-2016
4. Title of research project : Liquid anion-exchange extraction and
separation of precious metals by using High
Molecular Weight Amine (HMWA) as a
metallurgical extractant
5. (a) Name of the Principal Investigator : Dr. B. N. Kokare
(b) Department : Chemistry
(c) College where work has progressed: Raje Ramrao Mahavidyalaya, Jath
6. Effective date of starting of the project : 07-06-2014
7. Grant approved and expenditure incurred during the period of the report:
(a) Total amount approved Rs. : 4,35,000/-
(b) Total expenditure Rs. : 4,35,654/-
(c) Report of the work done : Separate sheet is attached (Appendix–I)
i. Brief objective of the project :
1) To synthesize 4-heptylaminopyridine (High Molecular Weight Amine). The main
objective is to determine optimum conditions for extraction of precious metals.
2) To analyze synthesized 4-heptylaminopyridine (High Molecular Weight Amine) by
spectral analysis like 1H NMR and IR.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 20
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 21
Appendix – II Final
Final Report of the Work Done
(First & Second Years)
Project Title: Liquid anion-exchange extraction and separation of precious
metals by using High Molecular Weight Amine (HMWA) as a
metallurgical extractant
First Year:
1) In the first phase, reference work and literature survey on high molecular weight
amine and their synthesis is done. Chemicals, glass wares and equipments for project
work are purchased.
2) Synthesis of 4-Heptylaminopyridine (High Molecular Weight Amine)
To a stirred solution of 4-aminopyridine (0.05 mol) in dry THF (40 mL),
sodium amide was added at 0oC and continued stirring for 30 min. The temperature of
the reaction mixture increased to room temperature and 1-bromoheptane was added
slowly. The reaction mixture was stirred at the ambient temperature for 1 h. The
reaction mixture was poured into water containing NH4Cl and extracted with
chloroform (150 mL). The chloroform extract was dried (Na2SO4) and evaporated on a
rotary evaporator to yield a residue which was crystallized to afford the corresponding
4-heptylaminopyridine.
N
NH2
+ NaNH2
N
NH
+ NH3
Na
THF/ Stirr
0 oC
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 22
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 23
Annexure – VII Final
UNIVERSITY GRANTS COMMISSION
BAHADUR SHAH ZAFAR MARG
NEW DELHI – 110 002
PROFORMA FOR SUBMISSION OF INFORMATION AT THE TIME OF SENDING
THE FINAL REPORT OF THE WORK DONE ON THE PROJECT
1. Title of the Project: “Liquid anion-exchange extraction and separation of
precious metals by using High Molecular Weight Amine (HMWA) as a
metallurgical extractant”.
2. NAME AND ADDRESS OF THE PRINCIPAL INVESTIGATOR: Dr. B. N. Kokare,
Department of Chemistry, Raje Ramrao Mahavidyalaya, Jath Dist- Sangli.
3. NAME AND ADDRESS OF THE INSTITUTION: Raje Ramrao Mahavidyalaya, Jath
Dist- Sangli 416 404.
4. UGC APPROVAL LETTER NO. & DATE: 47-601/13(WRO), dated: 26 March 2014
5. DATE OF IMPLEMENTATION: 07/06/2014
6. TENURE OF THE PROJECT: Two years (07/06/2014 to 06/06/2016)
7. TOTAL GRANT ALLOCATED : 4,35,000/-
8. TOTAL GRANT RECEIVED: 3,52,500/-
9. FINAL EXPENDITURE : 4,35,654/-
10. TITLE OF THE PROJECT: “Liquid anion-exchange extraction and separation
of precious metals by using High Molecular Weight Amine (HMWA) as a
metallurgical extractant”.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 24
11. OBJECTIVES OF THE PROJECT :
a) To synthesize high molecular weight amine (4-heptylaminopyridine).
b) Characterization of synthesized high molecular weight amine (4-
heptylaminopyridine).
c) The main objective is to develop solvent extraction method by using 4-
heptylaminopyridine for the extraction of palladium(II) and platinum(IV).
12. WHETHER OBJECTIVES WERE ACHIEVED (GIVE DETAILS):
a) High molecular weight amine (4-heptylaminopyridine) was easily synthesized.
b) The structure of synthesized high molecular weight amine (4-
heptylaminopyridine) is characterized by spectral analysis like 1H NMR and
FT-IR.
c) The synthesized high molecular weight amine (4-heptylaminopyridine) was
used to extract palladium(II) and platinum(IV).
13. ACHIEVEMENTS FROM THE PROJECT
a) Synthesis of new high molecular weight amine (4-heptylaminopyridine).
b) Characterization of these high molecular weight amine by spectral analysis.
d) Development of solvent extraction method for the extraction of palladium(II)
and platinum(IV).
14. SUMMARY OF THE FINDINGS ( IN 500 WORDS ):
High molecular weight amine (4-heptylaminopyridine) was easily synthesized
and characterization was done by using NMR and IR.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 25
a) IR spectrum
The IR spectrum of 4-heptylaminopyridine (Fig. 1) showed absorption band at 3427
cm-1 due to presence of –NH while at 1646 and 1545 cm-1 indicated presence of
carbon-nitrogen and carbon-carbon double bond respectively.
IR: 3427 (-NH (S)), 3052 (-CH, Ar.), 2957-2855 (-CH (S) (aliph.)), 1646 (-C=N (S)),
1545 (C=C) cm-1.
b) NMR Spectrum
Proton resonance assignments for the pure product were made using TMS as an
internal standard and chemical shift expressed in values, PMR (CDCl3, 300 MHZ,
Fig. 2).
NMR: CDCl3 (300 MHZ): , 0.851 (3H, t, -CH3); 1.61-1.81 (2H, m, -CH2); 2.4 (2H,
qn, -CH2); 3.23 (2H, qn, -CH2); 3.42 (2H, qn, -CH2); 4.35 (2H, qn, -CH2); 4.81 (2H, q,
-CH2); 6.5 (1H, S, -NH); 6.8-8.4 (4H, m, Ar-H) ppm.
The main objective of the project is to develop solvent extraction method for
the extraction of palladium(II) and platinum(IV).
1) Solvent extraction procedure for palladium(II)
In all the extraction studies, aqueous (Pd(II) ion in appropriate concentration
and 0.04 M sodium salicylate, pH was adjusted to 0.5) and organic (0.05 M 4-HAP in
xylene) phases in a ratio of 2.5:1 were shaken at room temperature in glass stoppered
separating funnel for 5 min. After phase disengagement, the aqueous phase was
separated, and loaded organic phase was stripped with 6.0 M ammonia (2 × 10 mL).
The concentration of palladium(II) from stripped solution was determined
spectrophotometrically using dithizone method [76].
2) Solvent extraction procedure for platinum(IV)
An aliquot of 200 µg of platinum(IV) solution was mixed with 0.0308 g of
ascorbic acid to make a concentration of 0.007 M in a total volume of 25 mL of the
solution. The pH of the aqueous solution was adjusted to 1.5 using dil. sodium
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 26
hydroxide and hydrochloric acid solution. The solution was then transferred into a 125
mL separating funnel and shaken with 10 mL of 0.06 M 4-heptylaminopyridine in
xylene for 2 min. After separating the two phases, the aqueous phase was discarded
and the organic phase was stripped with two 10 mL portions of water solution. After
being stripped with water, platinum(IV) was put into the aqueous phase quantitatively.
The stripped aqueous phase was evaporated to moist dryness and extracted into dil.
hydrochloric acid.
15. CONTRIBUTION TO THE SOCIETY (GIVE DETAILS)
The noble metals are resistant to corrosion and oxidation in moist air, unlike most
base metals. They tend to be precious, often due to their rarity in the earth’s crust.
Noble metals are rare, naturally occurring metallic chemical element of high economic
value. Historically, precious metals were important as currency but are now regarded
mainly as investment and industrial commodities. The determinations of these metals
in various samples have become increasingly important.
Solvent extraction procedure for palladium(II)
In all the extraction studies, aqueous (Pd(II) ion in appropriate concentration
and 0.04 M sodium salicylate, pH was adjusted to 0.5) and organic (0.05 M 4-HAP in
xylene) phases in a ratio of 2.5:1 were shaken at room temperature in glass stoppered
separating funnel for 5 min. After phase disengagement, the aqueous phase was
separated, and loaded organic phase was stripped with 6.0 M ammonia (2 × 10 mL).
The concentration of palladium(II) from stripped solution was determined
spectrophotometrically using dithizone method [76].
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 27
Solvent extraction procedure for platinum(IV)
An aliquot of 200 µg of platinum(IV) solution was mixed with 0.0308 g of
ascorbic acid to make a concentration of 0.007 M in a total volume of 25 mL of the
solution. The pH of the aqueous solution was adjusted to 1.5 using dil. sodium
hydroxide and hydrochloric acid solution. The solution was then transferred into a 125
mL separating funnel and shaken with 10 mL of 0.06 M 4-heptylaminopyridine in
xylene for 2 min. After separating the two phases, the aqueous phase was discarded
and the organic phase was stripped with two 10 mL portions of water solution. After
being stripped with water, platinum(IV) was put into the aqueous phase quantitatively.
The stripped aqueous phase was evaporated to moist dryness and extracted into dil.
hydrochloric acid.
Advantages: (i) A low concentration of extractant is required for the quantitative extraction of
palladium(II) and platinum(IV).
(ii) 4-Heptylaminopyridine forms an ion–pair complex with palladium(II) and
platinum(IV) in weak acid medium.
(iii) Extraction of palladium(II) and platinum(IV) has been carried out without the
addition of any synergent or modifier at room temperature.
(iv) Ecofriendly strippant (water) is used for the stripping of platinum(IV); its use in
this method follows one of the principles of green chemistry.
v) The developed method is free from interference from a large number of diverse
ions which are commonly associated with palladium(II) and platinum(IV). The
selectivity was also enhanced using suitable masking agents.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 28
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 29
Chapter I
General Introduction
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 30
Solvent Extraction
In recent years, liquid-liquid extraction has come to the front in analytical
chemistry as a popular separation art because of its quickness, absence of
complication and relevance to both macro and tracer amounts of metal ions. The
conditions of liquid-liquid extraction with its relevance are very well explained [1, 2].
Solvent extraction is based on the principle that the partition of solute in a
certain ratio between two immiscible liquid, one of which is usually organic solvent
and the other is water. In certain cases the solute can be transferred into the organic
phase more or less completely. The technique can be used for purposes of purification,
preparation, separation, enrichment and analysis, on all scales of working, from
microanalysis to production processes.
Solvent extraction may be an important step in the sequence that leads a pure
product in the organic, inorganic, or biochemical laboratory. Although complicated
apparatus is sometime employed, frequently only a separatory funnel is required.
Often a solvent extraction separation can be accomplished in a few minutes. The
technique is applicable over a wide concentration range and has been used extensively
for the isolation of extremely minute quantities of carrier-free isotopes obtained by
nuclear transmutation as well as industrial materials produced by the ton. Solvent
extraction separations are usually “clean” in the sense that there is no analog of co
precipitation with such system [3].
Solvent extraction process consists of following steps:
1. Consistent contacting of organic solvent with the aqueous phase containing
solute.
2. The solute is transferred from aqueous phase to the organic phase.
3. Equilibration of two liquid phases.
4. Separation of two immiscible liquid phases.
5. Stripping of solute from the organic phase to aqueous phase by the use of
suitable strippants.
Proceedings of International Conference on Solvent Extraction [ISEC] [4-21] is a
good sources of information on the solvent extraction and provide important records
of the latest developments and trends in solvent extraction. Information about solvent
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 31
extraction are very well explained in several monographs by Morrison and Freiser
[22], De, Khopkar and Chalmers [2], Sekine and Hasegawa [23], Alders [24], Starry
[25], Hanson [26], Marcus and Kertes [27].
Principles of solvent extraction
1) The distribution coefficient:
The distribution equilibrium between two liquid phases is governed by the
Gibbs phase rule, which stated mathematically as,
P + V = C + 2
Where, P = number of phases, V = degree of freedom and C = number of component.
In case of solvent extraction there are two phases namely aqueous and organic, while
solute is only the component in solvent and water phases and at constant temperature
and pressure.
i.e. P = 2, C = 1 and V = 1
At constant pressure and temperature, the rule predicts a variance of unity. This
means if we chose the solute concentration in one phase, the concentration of solute in
other phase is fixed. Hence there will be definite relation between the concentrations
of solute in each of the solvent. Phase rule predicts that a system consisting of two
immiscible solvents and one distributing solute has one degree of freedom. The ratio
of solute concentration is shown to be invariant i.e. independent of total concentration.
The relation between solute concentrations in both the phases is described by
distribution law.
2) The distribution law:
The distribution law is derived in 1898 by W. Nernst and it is related to the
distribution of a solute in the two immiscible liquids. For the equilibrium reaction
A (aq) A (org)(1)
The Nernst distribution law is written
KD =Concentration of Species A in organic phase
Concentration of Species A in aqueous phase=
[A]org
[A]aq
Where, KD = Distribution constant of the solute A
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 32
Strictly, this equation is valid only with pure solvents. In practice, the solvents are
always saturated with molecules of the other phase; e.g., water in the organic phase.
3) The distribution ratio (D):
The IUPAC definition of the distribution ratio (D), for a metal species M can
be written as
𝐷𝑀 =𝐶𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑎𝑙𝑙 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑐𝑜𝑛𝑡𝑎𝑖𝑛𝑖𝑛𝑔 𝑀 𝑖𝑛 𝑜𝑟𝑔𝑎𝑛𝑖𝑐 𝑝ℎ𝑎𝑠𝑒
𝐶𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑎𝑙𝑙 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑐𝑜𝑛𝑡𝑎𝑖𝑛𝑖𝑛𝑔 𝑀 𝑖𝑛 𝑎𝑞𝑢𝑒𝑜𝑢𝑠 𝑝ℎ𝑎𝑠𝑒
=[𝑀𝑡]𝑜𝑟𝑔
[𝑀𝑡]𝑎𝑞
(2)
When M is present in various differently complexed forms in the aqueous phase and
in the organic phase, [M t] refers to the sum of the concentrations of all M species in a
given phase (the subscript t indicates total M). It is important to distinguish between
the distribution constant (KD), which is valid only for a single specified species (e.g.,
MA2), and the distribution ratio (D), which may involve sums of species of the kind
indicated by the index, and thus is not constant.
4) Relation between distribution ratio and percentage extraction:
𝐷 =[𝑉𝑊
𝑉𝑂] 𝐸
(100 − 𝐸) (3)
Where, Vw is volume of aqueous phase
Vo is volume of organic phase
When volume of organic and aqueous phase are equal i.e. VO = VW, D reduces to
𝐷 =𝐸
100 − 𝐸 (4)
Further the extraction is considered to be quantitative when E = 100, under these
circumstances.
0
100
100100
100D (5)
5) Separation factor (α):
The separation factor (SF) is given by the ratio of distribution ratios of two
different metals. It is a measure of the ability to separate two metals from each other.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 33
According to IUPAC nomenclature the separation factor is denoted by ‘α’. The
separation factor ‘α’ is related to the individual distribution ratios as follows:
α =𝐷𝐴
𝐷𝐵 (6)
Where DA and DB is the distribution ratio of metal A and B respectively.
Classification of solvent extraction system
Nowadays, large numbers of commercial extractant are available for solvent
extraction and related technologies. Also so many researchers are taking efforts to
produce new reagents. The role of extractant in metal extraction is to form metallic
lipophile complexes which can be transferred from the aqueous phase to the organic
phase through a chemical interaction.
Several extraction mechanisms can be enumerated
1. Extraction by ion-pair formation
I) Anion exchange
Basic extractants (B) are organic reagents which can easily form a salt in the
organic phase while in contact with an aqueous acid solution (HX)
Borg + HXaq →BH+X-org (I)
Where the subindexes org and aq denote the organic phase and aqueous phase
respectively. Then, contacting the organic phase with an aqueous solution containing
anionic metal species MXn-(n-m) (n>m), anoin exchange occurs as follows:
(n-m) BH+X-org + MXn
-(n-m)aq → (BH+
(n-m)MX n-(n-m))org + (n-m)X-
aq (II)
Thus, the amine salt should be considered as being the extracting reagent and
not the free amine.
High-molecular weight amine and quaternary ammonium halide are basic
extractants currently used in solvent extraction process.
e.g. Extraction of Re(VII) from nitrate media with secondary amine.
RR'NH(org)
+ HNO3
(aq)
+ RR'NH2 NO3
-
RR'NH2 NO3
+ -
(org)
(org)
+ ReO4
-
(aq)[RR'NH2
+ReO4
-
(org)NO3
-
(aq)
] +
+[ ]
[ ]
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 34
II) Cation exchange
Organic acids (HL) can extract metallic cations (M+m) according to the
reaction:
mHLorg + M+maq → MLm org + mH+
aq (III)
The above equation describes a cation exchange reaction wherein hydrogen
ions are exchanged for the metal cation. Extractants which have been found useful
extracting metals by this mechanism are organic derivatives of phosphorous acids,
monocarboxylic acids and sulphonic acids etc.
e.g. The extraction of copper(II) with 1, 10-phenanthroline in chloroform from
hydrochloric acid media
Cu 2+ + o-phen [ Cu (phen) ]
[Cu (phen) ] + 2ClO4
_[Cu (phen)++ 2ClO4 ]
_
2+
2+
(aq)
(aq) (org)
(org) (org)
(org)
2. Extraction by Chelation
This mechanism is performed by acidic extractants that possess donor groups
capable of forming bidentate complex with metal ions. The equilibrium chemical
reaction describing the metal extraction is the same as that reported for cation
exchange system. Examples of chelating extractants β-diketones, oxine, cupferron
DMG etc.
e.g. Extraction of Al3+ from acetate medium with oxine
N
OAl
3
Oxine Al complex
3. Extraction by solvation
Solvating or neutral extractants (S) possess only donor groups that do not
contain dissociating protons, and because no anionic or cationic groups are available
in the molecule, the metal species are extracted from the aqueous phase as neutral
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 35
complexes and the neutralizing ion as a water soluble negatively charged ligand (X-).
The extraction reaction can be written as:
ySorg + M+maq + mX-
aq → MXmSy org (IV)
As solvating extractants can be mentioned organic reagents containing oxygen
bonded to carbon, such as ethers, alcohols and ketones and those containing oxygen or
sulphur bonded to phosphorus as phosphoric esters, phosphonic oxides and
phosphonic sulphides.
e.g. Extraction of iron(III) by diethyl ether from 6 M HCl medium
]
]
FeCl3 + HCl [FeCl4-
H+
]
FeCl4-
H+
H2O+ [ H3O+
FeCl4-
[ H3O FeCl4+ -
+ ether [H+
(ether) FeCl4- (ether)]
4. Synergistic extraction
In this class there is an enhancement in the extraction by the use of two
extractants. The synergic extraction involved two steps. In first step metal ion reacts
with anionic ligand to form neutral complex. Where the positive charge on the metal
ion is neutralized by anion. At the same time equal numbers of water molecules are
removed by the negatively charged ligands depending upon number of bonding sites
from the coordination sphere of metal ion.
In the second step, neutral ligand react with uncharged complex and equal or
nearly all the remaining water molecule are removed from coordination sphere of
metal complex and finally there is formation of adduct [UO2(TTA)2TBP]
e.g. The extraction of uranium with tributyiphosphate (TBP) as well as 2-
thenoyltrifluoroacetate (TTA).Although either TBP or TTA are individually capable
of extracting uranium, if a mixture of these two extractants is used we get enhanced
extraction.
SC
H2C C CF3
OOS
C CH
C CF3
OHO
Keto TTA enol HTTA
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 36
SC C
HC CF3
OHOS
C CH
C CF3
O-O
HTTA TTA-
+ H+
SC C
HC CF3
O-O
[UO2(H2O)4]2+ + 2
TTA-
[UO2(H2O)(TTA)2]
[UO2(H2O)(TTA)2] + U
O
O
O
TBP
O
O
C CH
C
O
C4H3S+ H2OTBP
CF3
C
CF3
HC
C
C4H3S
Techniques in Extraction [22]:
1. Choice of solvent:
Perhaps the most important consideration is the selection of solvent for use in a
particular extraction procedure is the extractability of the element of interest. A
consideration of the solubility of the solute in a particular solvent, the ease of recovery
of the solute from the solvent is important for subsequent analytical processing. The
boiling point of the solvent or the ease of the stripping by chemical reagents into
selection of solvent when the possibility of a choice exists. Similarly, the degree of
miscibility of the two phases, the relative specific gravities, viscosities, and tendency
to form emulsions should be considered. From the point of view of safety, the toxicity
and the flammability of the organic solvent obviously enter into the choice.
2. Stripping:
Stripping is the removal of the extracted solute from the organic phase for further
analysis. In many colorimetric procedures the concentration of solute of interest is
determined directly in the organic phase. However, the other conventional methods of
estimation are to be employed or further separation steps are required, to remove the
solute from the organic phase to a suitable medium. Depending on the volatility of the
organic solvent, the simplest procedure is to add a small volume of water to the extract
to hold the solute and to evaporate the volatile solvent on a steam bath. The addition
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 37
of acid to the water before evaporation of volatile solvents in which chelate complexes
are dissolved helps to break the complex, thereby causing the metal ion to enter the
water solution. Sulphuric acid, nitric acid and perchloric acid were some times used to
destroy the residual organic matter.
Majority of the times, it is necessary to strip the solute from the solvent by
chemical means. The usual procedure being to shale the solvent with a volume of
water containing acids or other regents under optimum conditions whereby extractable
complex is separated. Thus metal ions are then quantitatively back extracted into the
stripping aqueous phase.
3. Backwashing:
An auxiliary technique used with batch extractions to effect quantitative
separation of elements is that of back washing. The combined organic phases after
several extractions contains practically some of the impurities and all the elements that
have been extracted to a much smaller extent depending on their relative distribution
ratios. This combined organic phase, when shaken with one or more small portions of
fresh aqueous phase containing the optimum reagent conc., salting out reagent etc.,
will result in a redistribution of the impurities, as well as of the major component,
between two phases. The bulk of the impurities, however, will be back-extracted to
the fresh aqueous phase, since their distribution ratios are much smaller.
4. Treatment of emulsion:
Mixing or agitating certain combinations of immiscible liquids, an emulsion
may result whereby one liquid is dispersed in a continuum of the other. The stability
or permanence of the dispersion is its most important property since it is necessary to
separate the phases for further steps in the analytical procedure. For an emulsion to
break or separate into its phases, both sedimentation and coalescence of the droplets of
the dispersed phase must occur.
The presence of a small amount of a solid phase at the interface often prevents
coalescence of emulsions, and filtration of both phases serves to prevent trouble.
Another method for reducing the tendency for emulsification is the addition of neutral
salts, which possibly increase the surface tension or the density. Another way of
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 38
avoiding emulsification is to allow only a small amount of the aqueous solution to
come in contact with a relatively large amount of the original solvent.
5. Variation of oxidation state:
Modification of the oxidation states of some of the ions present in solution, so
as to prevent the formation of metal complex necessary for extraction e.g. by reducing
iron(III) to iron(II) which does not extract, the extraction of iron from chloride
solution was prevented. Conversely for complete extraction of element proper
adjustment of valence state is required. These variations in oxidation state are
accomplished by the addition of the appropriate oxidizing or reducing agent.
6. Use of masking agents:
Masking agents are themselves metal-complexing agents. Which serve to
prevent particular metals from taking part in their usual reactions and thus remove
their interference without the necessity of an actual separation. In solvent extraction,
masking agents are used to prevent certain metals from forming extractable complex
and thus to greatly increase the selectivity of the extraction method in which masking
is employed. Masking was carried out by cyanide, tartrate, citrate, fluoride and EDTA
e.g. nickel may be extracted with dimethylglyoxime in the presence of cobalt if
cyanide is first used to mask the cobalt.
7. Use of salting out agents:
The term salting out agent is applied to those electrolytes whose addition
greatly enhances the extractability of complexes. The function of salting out agent
would be primarily of providing a higher concentration of complexing anion which,
by mass action would increase the concentration of complex and thus improve the
extraction. Water is probably bound as a shell of oriented water dipoles around the
ion and thus becoming unavailable as “free solvent”. Addition of salting out agents
decreases the dielectric constant of the aqueous phase, which favours the formation
of the ion association complexes.
Salting-out agents have been used with great success in separation involving
the halide and thiocyanate system.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 39
Methods of extraction:
In most situations encountered in analytical chemistry the technique of liquid-
liquid extraction is employed to separate the solute of interest from substances that
interfere in the ultimate quantitative determination of the material. Most of the
analytical separations involving extraction are based on the favorable separation
factor, the extractions in which the separation factor approaches unity, it is necessary
to employ fractionation methods in which transfer, recombination and distribution of
various fractions are performed a sufficient number of times to achieve separation
[28].
Analytical chemistry, three basic types of solvent extractions are generally
utilized namely, I) batch extraction, II) continuous extraction and III) continuous
countercurrent extraction.
I. Batch extraction:
The method in which the volumes of solution as well as the volume of solvent
are contacted until equilibrium is attained and the two layers are then separated. This
is very simple extraction method used for the analytical separations. It is also used to
study the unknown systems and designed to yield the quantitative distribution
information.
If distribution ratio is not already known, it may be obtained by equilibrating
equal volume of the solution and extracting solvent. Batch extraction may be used to
advantage when the distribution ratio is large.
II. Continuous extraction:
When the distribution ratio is relatively small continuous extractions are
particularly applicable, so that to effect quantitative separation a large number of
batch extractions would normally be necessary. The continuous extraction device
operates on the principle, which consists of distilling the extracting solvent from a
boiler flask and condensing it and passing it continuously through the solution being
extracted. The efficiency of continuous extraction depends on the viscosity of the
phases, the values of distribution ratio, and the relative volumes of two phases.
The efficiency of continuous extraction processes may be conveniently evaluated
by a method devised by Bewick, Currah, and Beamishm [29] Continuous extraction
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 40
can conveniently be arranged according to whether the solvent is lighter than or
heavier than the phase being extracted.
III. Continuous countercurrent extraction:
This type of extraction involves a process whereby the two liquid phases are
caused to flow counter to each other. It is used to great advantage for separating
material for isolating or purification purpose, and it is also used extensively in
engineering problems.
Solvent extraction plays very crucial role in analytical chemistry and was
proved by number of research articles. The various techniques of solvent extraction
was introduced by Morrison and Freiser [22], Marcus and Kertus [6], Sekin and
Hasegava [23], Starry [25], Hanson [26].
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 41
References:
[1] F. W. Foiled, D. Kealey, Principals and Practice of Analytical Chemistry,
International textbook Company limited, 450 Edgware Rd., London W2 IEG
1975.
[2] A. K. De, S. M. Khopkar, R. A. Chalmers, Solvent Extractions of Metals, Van
Nostrand, Reinhold Co., London (1970).
[3] R. A. Day Jr., A. L. Underwood, Quantitative analysis, 6th ed, Prentice-Hall,
Inc., Englewood Cliffs, N. J., USA., 1-2 (1998) 462.
[4] H. A. C. McKay, Proceedings of the International Solvent Extraction
Conference, McMillan, London (1963).
[5] D. Dyrssen, Proceedings of the International Solvent Extraction Conference,
Gothenburg (1966), North-Holland Publishing Co., Amsterdam (1967).
[6] Y. Marcus, A. S. Kertes, Proceedings of the International Solvent Extraction
Conference, Jerusalem (1968), Wiley, Interscience, NewYork (1969).
[7] J. G. Gregory, Proceedings of the International Solvent Extraction Conference,
Hague (1971), Society of Chemical Industry, London,(1971).
[8] C. V. Jeffreys, Proceedings of the International Solvent Extraction Conference,
Lyon (1974).
[9] M. I. H. Baird, Proceedings of the International Solvent Extraction Conference,
Toronto (1977). Canadian Institute of Mining and METALLURGY, Society of
Chemical Industry, (1977).
[10] G. Duyckaertes, Proceedings of the International Solvent Extraction
Conference, Liege, Belgium (1980).
[11] J. C. King, Proceedings of the International Solvent Extraction Conference,
Denver, U.S.A. (1983).
[12] E. Blab, W. Nish, Proceedings of the International Solvent Extraction
Conference, Munich (1986).
[13] Y. A. Zolotov, Proceedings of the International Solvent Extraction Conference,
Moscow, USSR (1988).
[14] T. Sekine, Proceedings of the International Solvent Extraction Conference,
Kyoto-Japan (1990).
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 42
[15] Proceedings of the International Solvent Extraction Conference, York (1993).
[16] Proceedings of the International Solvent Extraction Conference, Melbourne
(1996).
[17] Proceedings of the International Solvent Extraction Conference, London
(1999).
[18] Proceedings of the International Solvent Extraction Conference, South Africa
(2002).
[19] Proceedings of the International Solvent Extraction Conference, Beijing, China
(2005).
[20] Proceedings of the International Solvent Extraction Conference, Tuscon, U. S.
(2008).
[21] Proceedings of the International Solvent Extraction Conference, Sangiago,
Chile (2011).
[22] G. H. Morrison, H. Freiser, Solvent Extraction in Analytical Chemistry, John
Wiley and sons, Inc., London, (1966).
[23] T. Sekine, Y. Hasegawa, Solvent Extraction Chemistry, Marcel Dekkar Inc.,
New York (1977).
[24] L. Alders, Liquid-Liquid Extraction, Elsevier, Amsterdam (1959).
[25] J. Starry, The Solvent Extraction of Metal Chelates, Pergamon, London (1964).
[26] C. Hanson, Recent Advances in Liquid-Liquid Extractions, Pergamon, London
(1971).
[27] Y. Marcus, A. S. Kertes, Ion Exchange and Solvent Extraction of Metal
Complexes, Wiley, Interscience, New York (1969).
[28] L. C. Craig, D. Craig, Techniques of organic chemistry, edited by A.
Weissberger, Vol. III, Part I, second edition, Interscience Publishers, Inc., New
York, (1956).
[29] H. A. Bewick, J. E. Currah, F. E. Beamish, Anal. Chem., 21 (1949) 1325.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 43
Chapter II
4-Heptylaminopyridine: Synthesis and
characterization
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 44
2.1 Solvent extraction by high molecular weight amines
In analytical chemistry, nuclear industry, hydrometallurgy [1], mining industry,
etc high molecular weight amines have been widely used as liquid ion-exchanger for
the purification and recovery of various metal species by means of solvent extraction
[2]. High molecular weight primary, secondary and tertiary amines that are
organophilic weak bases which are used for solvent extraction of anionic species in
acidic aqueous solution. The interaction of these extractants with the anionic species
due to electrostatic force of attraction this sense as the ion-pair forming extractant.
These high molecular weight amines can be regarded as ‘liquid anion-exchangers’ in
the same way as the alkyl phosphoric acids can be regarded as ‘liquid cation-
exchangers’. This is because the extraction equilibria can at least formally, be
expressed by an ion-exchange reaction of anionic metal complex in the aqueous phase
with ligand anions combined with the extractant in the organic phase. Since the
extraction proceeds via formation of ion-pair, it depends on the charge and the ionic
size, and no specificity can be expected among anions of the same charge and size. As
the extractants forms variety of complexes with thiocyanate, nitrate, sulphate, halide
and number of other inorganic and organic anions it is used specifically for the
separation of many metal ions.
The primary, secondary and tertiary amines are the organic derivatives of
ammonia used for the extraction of metal ions, by anion exchange reaction with metal
anionic complex. These three types of amines acts as weak bases in aqueous phase;
can accept one proton and form anionic salt, while quaternary ammonium ions do not
require protonation before they can react. The lower molecular weight amines are very
soluble in water, due to this for solvent extraction high molecular weight amines are
preferred.
The basicity of primary or secondary amines in aqueous solution is not greatly
affected by the chain length. However, that of tertiary amines increases as the
molecular weight increases [3, 4]. The basicity of secondary amines in aqueous
solution is somewhat higher than primary or tertiary amines. The basicity of these
three classes of amines in organic solvent is different from that of aqueous solution
[5].
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 45
2.2 Solvent extraction of metals from organic acid solutions
It is important at this stage to consider the advantage of weak organic acid
medium over mineral acid medium. The different advantage of weak organic acid
media is the ease of adjustment of pH, the facility of controlling the concentration of
complexing ligand and the wide difference in pH at which various metals form
anionic complexes. Due to high stability of metal organic acid complexes, the organic
acid medium offered better separation of metals. The comparative study of back
extraction of complexes from the organic phase by fully exploiting the difference of
various metals to back extract in aqueous phase.
There are several general features which are essential for an extraction, if one has to
achieve the selective extraction of metals. These features are as follows:
The ability to extract the metal at desired acidity or pH.
To be selective for the required metal.
Ease of formation of complex with metal of interest and high solubility of
metal organic species in the organic phase.
Ease of recovery of the metal from organic phase.
It must be stable throughout the principle stage of solvent extraction.
It is to be prepared in laboratory on large scale.
To have acceptable rates of extraction and stripping.
Regeneration of extractant for recycling in economically large scale process.
Due to greater solubility in water, primary amines are used less frequently as
compared to secondary amine.
2.3 Extraction by ion-pair formation
The value of the ion-pair formation constant K is related to the dielectric constant (),
and temperature (T) by the expression
𝐾 =4𝜋𝑁𝑒2
1000∈𝐾𝑇Q (b),
Where, b = 𝑒2
𝑎∈𝐾𝑇
N = Avogadro’s number
e = Charge
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 46
K = Boltzmann constant
T = Absolute temperature
Q (b) = Calculable functions
a = Empirical parameter dependent upon the distance between charge centre of the
paired ions, when in contact.
Since the organic solvents used in extraction have a dielectric constant () less
than 40, ion association will be extensive in such solvents the decrease in the
dielectric constant of the aqueous phase by addition of salt favours ion-pair formation.
The effect of temperature on the value of K will depend on the temperature variation
of the dielectric constant. In solvents higher dielectric constants () deceases
markedly with temperature. So that T values fall with increasing T. In such solvents,
ion association increases with increasing temperature. In solvents of very low
dielectric constant, T increases with increase in temperature as the value of does
not change much, with the result that ion association falls off with rise in temperature
in solvents of this type.
According to Bjerrum equation [6] it is evident that ion association depends on
the value of ‘a’, decreasing with increasing ‘a’ values. If the value of ‘a’ does not
change appreciably with change in solvent, then the value of ion-pair constant (K) can
predicted in any solvent from its known value of ‘a’ in one solvent. It is fact that K
depends only on dielectric constant if ‘a’ and the temperature remains constant.
2.4 Common high molecular weight amines
Solvent extraction has emerged as one of the more popular separation
techniques because of its ease, simplicity speed, applicability both to trace and macro
level of metal ions. An organic solution of high molecular weight amines and amine
salts has been shown to be excellent extractants for metal ions from aqueous solution.
Smith and Page [7] reported that acid binding properties of high molecular weights
amines depends on the fact that acid salt of these bases are, in general, essentially
insoluble in water but readily soluble in organic solvent.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 47
Primary amines are comparatively more water soluble than secondary and
tertiary amines and hence less frequently used for the extraction. Thus for the solvent
extraction of metal from aqueous medium secondary amines are used.
Extraction of many metal ions was carried out from organic acids,
monocarboxylic acid like salicylate, succinate and dicarboxylic acids like oxalic,
citric, tartaric, malonic. The extraction greatly depends on the nature, concentration of
amine and pH.
The most common high molecular weight amines used for the solvent
extraction studies are given in the table:
Table 1: Common high molecular weight amines
Amine Name Structure
Primary
n-Octylaniline
NH2
C8H17
Primene JMT H2N-C(R)(R’)(R”)
Octadecylamine CH3(CH2)17NH2
2-Octylaminopyridine
NNH-CH2
- (CH2)6- CH3
N-n-Octylaniline NH -CH2- (CH2)6 CH3
-
N-n-
Octylcyclohexylamine
(N-n-OCA)
NH (CH2)7- - CH3
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 48
Secondary N-n-
Decylaminopyridine
N
NH -(CH2)9 CH3-
Amberlite LA-1
[N-Dodecyl
(trialkylmethyl)amine]
HN
C(R) (R') (R'')
- CH2 C CH3- --
CH3 CH3
CH3CH3
CH2CH CHCH2C
Amberlite LA-2
[N-lauryl
(trialkylmethyl)amine]
HN
C(R) (R') (R'')
CH2(CH2)10CH3
N-n-Benzylaniline NH CH2
Tertiary
Tri-n-Dodecylamine
N-[CH2(CH2)10CH3]3
N-Methyl-Di-n-
Octylamine H3C
_ __ _(H2C)7
N
CH3
(CH2)7 CH3
Tri-n-Benzylamine
(TBA) N
Tri-octylamine (TOA) N-[(CH2)7CH3]3
Tri-iso-octylamine
(TIOA)
N-[C8H17]3
Aliquat 336 S
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 49
Quarternary
(Trialkylmethyl-
ammonium chloride)
[CH3-N-(CH2)7-11(CH3)3]+Cl-
Zephiramine
(Tetradecyldimethyl
benzyl ammonium
chloride)
H3C (CH2)13 N
CH3
CH3
+
Cl
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 50
2.5 4-Heptylaminopyridine (4-HAP) as an extractant
4-Heptylaminopyridine (4-HAP) as a novel extractant was prepared according
to the method reported by Singh, Kim and Lee [8] and used as an extractant. 4-
Heptylaminopyridine acts as secondary amine. In addition, the presence of heptyl
group renders this amine less soluble in water. There is no emulsion formation. It can
form ion-pair complex with metal ion easily. The extraction equilibria for ion-pair
formation can be expressed as,
[4-HAP] (org) + HA (aq) [4-HAPH+A-] (org) (1)
[4-HAPH+A-] (org) + B- (aq) [4-HAPH+B-] (org) + A- (aq) (2)
Where, A- = anion of weak organic acid
B- = metal-acid anionic complex
4-HAP = 4-Heptylaminopyridine
2.6.1 Synthesis of 4-Heptylaminopyridine (4-HAP)
To a stirred solution of 4-aminopyridine (0.05 mol) in dry THF (40 mL),
sodium amide was added at 0oC and continued stirring for 30 min. The temperature of
the reaction mixture increased to room temperature and 1-bromoheptane was added
slowly. The reaction mixture was stirred at the ambient temperature for 1 h. The
reaction mixture was poured into water containing NH4Cl and extracted with
chloroform (150 mL). The chloroform extract was dried (Na2SO4) and evaporated on a
rotary evaporator to yield a residue which was crystallized to afford the corresponding
4-heptylaminopyridine.
N
NH2
+ NaNH2
N
NH
+ NH3
Na
THF/ Stirr
0 oC
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 51
+
N
NH Na
StirrBr-CH2-(CH2)5-CH3
1 hr.
N
NH-CH2-(CH2)5-CH3
+ NaBr
4-Heptylaminopyridine is white solid, which is readily soluble in xylene, toluene,
benzene, carbon tetrachloride, chloroform and acetone. Recrystallisation involves
huge losses. We recrystallised 4-HAP from acetone and obtained a product containing
99.9% of the main component. The yield was 75-85%. The purity was checked by
TLC and melting point was 44± 0.50C.
2.6.2 Characterization
a) IR spectrum
The IR spectrum of 4-heptylaminopyridine (Fig. 1) showed absorption band at
3427 cm-1 due to presence of –NH while at 1646 and 1545 cm-1 indicated presence of
carbon-nitrogen and carbon-carbon double bond respectively.
IR: 3427 (-NH (S)), 3052 (-CH, Ar.), 2957-2855 (-CH (S) (aliph.)), 1646 (-C=N (S)),
1545 (C=C) cm-1.
b) NMR Spectrum
Proton resonance assignments for the pure product were made using TMS as an
internal standard and chemical shift expressed in values, PMR (CDCl3, 300 MHZ,
Fig. 2).
NMR: CDCl3 (300 MHZ): , 0.851 (3H, t, -CH3); 1.61-1.81 (2H, m, -CH2); 2.4 (2H,
qn, -CH2); 3.23 (2H, qn, -CH2); 3.42 (2H, qn, -CH2); 4.35 (2H, qn, -CH2); 4.81 (2H, q,
-CH2); 6.5 (1H, S, -NH); 6.8-8.4 (4H, m, Ar-H) ppm.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 52
The molecular structure of 4-Heptylaminopyridine is given as below,
N
NH-CH2-CH2-CH2-CH2-CH2-CH2-CH3
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 53
Fig. 1 IR Spectrum of 4-HAP
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 54
Fig. 2 NMR Spectrum of 4-HAP
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 55
References:
[1] E. Hogfeldt, S. Alegret, Ed., Ellis Horwood Chichester, UK, (1988) p. 36.
[2] B. C. Bhatta, S. Mishra, Int. J. of Non. Met., 3 (2014) 9.
[3] J. Clark, D. D. Perrin, Quart. Rev. (London), 18 (1964) 295.
[4] H. K. Hall, J. Am. Chem. Soc., 79 (1957) 5441.
[5] A. Rieure, M. Pumeau, B. Tremillon, Bull. Soc. Chim., Fr. (1964) 1053.
[6] N. Bjerrum, Kgl. Danske Videnskab. Selskab Mat. fys. Medd., 7 (1926) 9.
[7] E. L. Smith, L. E. Page, J. Soc. Chem. Ind., (London) 67 (1948) 48.
[8] O. M. Singh, S. J. Singh, S. N. Kim, S. G. Lee, Bull. Korean Chem. Soc., 28
(2007) 115.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 56
Chapter III
Development of a solvent extraction system
with 4-heptylaminopyridine for the selective
separation of palladium(II) from synthetic
mixtures, catalysts and water samples
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 57
3.1 Introduction
Platinum group metals (PGMs) are of great practical importance and they have
a wide range of industrial applications, e.g. as catalysts in organic processes, value-
added components in metal alloys and the vehicle catalytic converter system. They are
used in the chemical, pharmaceutical, petroleum, electronic industries, and jewelry
making. These wide applications of PGMs, especially palladium(II), have increased
the palladium demand by 3.5% in 2007 to a total of 6.84 million ounces, whereas the
natural resources are limited [1, 2]. The use of palladium and platinum as catalyst in
the catalytic converters of cars and their eventual spread in the environment and also
the accumulation in wastewater by rain intensified environmental concerns. Since
palladium has no known biological role, all palladium compounds should be regarded
as highly toxic [3] similarly, palladium(II) can bind to thiol containing amino acids,
proteins, DNA, and several biomolecules and adversely affect the cellular processes
[4]. Therefore, the palladium(II) is strictly limited to be 5–10 ppm level by the
european agency for the evaluation of medicinal products [5]. The effective
palladium(II) extraction and recovery from both natural ore and industrial waste are
quite important from the viewpoint of full utilization of resources. Therefore, the most
important reasons for palladium(II) ions extraction, separation, and recovery are the
environmental concerns and economical impact.
Many analytical methods have been developed to determine the presence of
palladium(II) ions in clinical, environmental, industrial, and pharmaceutical samples
such as spectrophotometry, atomic absorption spectrometry, solid phase micro
extraction, high performance liquid chromatography, X-ray fluorescence,
electrochemical methods, Inductively Coupled Plasma-Atomic Emission
Spectrometry (ICP-AES) [6–11]. However, many of these are limited by
instrumentation cost, high training requirements, being cumbersome, time consuming
and unsuitable, especially in developing or less developed countries [12–14]. From the
viewpoint of analytical chemistry, there is increasing demand to develop reliable,
selective, sensitive methods to extract and separate the palladium(II) ions. Solvent
extraction also called liquid–liquid extraction is a process which allows separation of
two or more components, e.g. metal ions making use of their unequal solubilities in
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 58
two immiscible liquid phases. The solvent extraction is a suitable method for the
removal of PGMs from low concentrated sources, because it offers a number of
advantages like high selectivity and metal purity. Besides, more efficient removal of
metals is possible by the use of a multistage extraction.
3.2 Literature of the previously reported liquid-liquid extraction method for
palladium(II)
The fullerene black impregnated with trioctylamine was applied for the
extraction of palladium(II) from aqueous HCl medium [15]. The solvent extraction of
palladium(II) from aqueous chloride medium was carried out by N-benzoyl-N’, N’-
diethylthiourea [16]. Recovery of palladium(II) from spent catalysts was achieved
with Cyanex 921 from aqueous hydrochloric acid media by solvent extraction
technique [17]. In the solvent extraction of palladium(II) from chloride solution,
palladium(II) was extracted into Alamine 336 phase [18]. Extraction of palladium(II)
with Bis(2,4,4-trimethylpenty)phosphinodithioic acid from chloride solution has been
examined [19], palladium(II) was first selectively and quantitatively extracted into
chloroform. Palladium(II) was extracted from the aqueous solutions of their chloro
complexes using an N, N-dimethyldithiocarbamoylethoxy substituted calix [4] arene
[20].
The extractive separation of palladium(II) was analysed using a column packed
with divinylbenzene homopolymeric microcapsules containing tri-n-octylamine
(TOA) [21]. The proper selection of eluent helps the quantitative elution of
palladium(II) from column. 4-Alkylphenylamines had stronger interfacial activity so it
was effectively utilized as phase transfer catalyst to enhance the rate of extraction of
palladium(II) [22]. The extraction of palladium(II) with 1-[[2-(2,4-dichlorophenyl)-4-
propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole from HCl solutions has been
investigated [23]. The extraction complexes of palladium(II) by the novel ligands,
namely, N,N,N’,N’-tetra-(2-ethylhexyl) thiodiglycolamide (T(2EH)TDGA) and
N,N,N’,N’-tetra-(2-ethylhexyl) dithiodiglycolamide (DTDGA) [24] was determined
by extended X-ray absorption fine structure spectroscopy (EXAFS). The palladium(II)
ion, exhibiting 2 : 1 stoichiometry. Complex of palladium(II) and 2,2’-dithiodianiline
(DTDA) was extracted from an aqueous solution at pH 3 and determined by
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 59
spectrophotometric method [25]. Palladium(II) in synthetic mixtures, an alloy and
catalyst sample was successfully determined. Dicyclohexyl-18-crown-6 (DC18C6)
was used for the quantitative determination of palladium(II) from hydrochloric acid
and potassium thiocyanate media. Method was on the extraction and back-extraction
of palladium(II) has been developed [26]. Ketone derivative of calyx[4]arene was
used in nitrate medium for solvent extraction of palladium(II) [27]. Solvent extraction
method was developed for palladium(II) with 1-Benzoyl-3-[6-(3-benzoyl-thioureido)-
hexyl]-thiourea from nitric acid solutions [28]. N, N’–dimethyl-N, N’ –
diphenyltetradecylmalonamide (DMDPHTDMA) in 1, 2-dichloroethane was used for
the investigation of solvent extraction route for the separation of palladium(II) in
hydrochloric acid media [29]. Selective sorbent extraction of Pd(II) was carried out
and then separated as N, N-diethyl-N’-benzoylthiourea complex by an automated
column pre-concentration procedure [30]. Cyanex 923 was used for extraction and
separation of palladium(II) in chloride media at 4.0 – 5.0 M HCl [31]. Palladium(II)
was successfully stripped with 1:1 HCl + HClO4 in single step. Method was more
applicable by using SnCl2 as a labilising agent for the extraction of Pd(II).
Quantitative extraction and separation of Pd(II) from salicylate media using Aliquat
336 was studied [32]. Determination of extracted palladium(II) was carried out by
PAR method. Extraction of palladium(II) by bisacylated diethylenetriaminefrom
hydrochloric acid solutions was carried out [33]. N, N-Di(2-
ethylhexyl)aminomethylquinoline (DEQ) was used as the selective extractant for the
extraction of palladium(II) from the associated metal ions [34]. Pd(II) was selectively
extracted from precious metals and base metals from acidic chloride media has been
examined using theophylline derivatives [35]. Phosphonium ionic liquid:
trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101) was used as a novel
reagent for extraction of palladium(II) from HCl medium [36]. The extraction was
very fast and efficient, nearly 98% of palladium(II) was quantitatively extracted.
The extraction of palladium(II) from hydrochloric acid solutions was carried out
with Aliquat 336 [37]. Palladium(II) can be extracted from aqueous medium to the
dichloromethane layer using quinoline-2-carboxalde- hyde 2-pyridylhydrazone [38].
Tin(II) chloride concentration was greatly influenced on the extraction of
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 60
palladium(II). Solvent extraction separation of palladium(II) was carried out with 2-
ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) in toluene in the
presence of stannous chloride [39], 6 x 10-4 M PC-88A was enough for quantitative
extraction of Pd(II). The extraction behavior of base metals and precious metals from
aqueous chloride media was analyzed by a novel type of extractant p-(1, 1, 3, 3-
Tetramethylbutyl) phenyl hydrogen [N, N- di(2-ethylhexyl) aminomethyl phosphonate
[40]. This reagent has selectivity towards palladium(II) ions in the low acidic region.
The kinetics of palladium(II) extraction from chloride media with 1,2-bis(tert-
hexylthio)ethane were developed, the palladium complex was extracted with a
stoichiometry of 1: 1 [41]. 1-Octyltheobromine was utiliized to study extraction
equiliburium of palladium(II) from acidic chloride media [42]. Solvent extraction of
palladium(II) was studied involving ion-pairing of bromocomplexes of palladium(II)
with hexadecylpyridinium bromide (HDPB) [43]. The extraction reaction occurred
very effectively at the interface and thus the extraction rate was fast. Extraction of
palladium(II) ions using tri-n-octylamine xylene base supported liquid membranes
was carried in hydrochloric acid medium and stripping of palladium(II) was carried
out by agent like nitric acid [44]. Ionic liquids like trioctylammoniumbis
(trifluoromethanesulfonyl)amide ([TOAH][NTf2]) and trioctylammonium nitrate
([TOAH][NO3]) [45] were successfully implemented for extraction of palladium(II)
from 0.1 M HCl. Extraction of palladium(II) in the TRUEX and PUREX from nitric
acid solution by octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide was
carried out effectively [46]. Macrocyclic endo-receptors in hydrochloric acid were
successfully applied for the solvent extraction of palladium(II) The DCH18C6 in
dichloroethane excellently extracted palladium(II) in the presence of KSCN [47].
Quantitative extraction of palladium(II) with thiacalix[4]arenes from nitric acid
nitrate–nitrite solutions method was developed and applied for the separation of
fission noble metals, including their heterometallic complexes [48].
Thiodiglycolamide was used for the rapid separation of palladium(II) in HCl solutions
[49]. Thiamacrocycles-synergized sulfonic acid extraction system was developed for
solvent extraction of palladium(II) in acidic nitrate solutions [50]. Di-(2-
ethylhexyl)thiophosphoric acid was used for selective extraction of palladium(II) as an
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 61
impregnated resins by adsorption of this extractant on Arnberlite XAD2 by means of a
dry impregnation method [51]. Palladium(II) was determined and separated by online
solid phase extraction by FIA-FAAS system. The method was successfully used for
determination of palladium in alloy and ore sample [52]. Palladium(II) was
determined from a pegmatite rock from Campo Largo County, Parana State, Brazil
and mineral veins of quartz by using [5-(4-dimethylaminebenzylidene)rhodanine] and
methyl isobutyl ketone at pH 2.4 [53]. Utility of alkane-1,ω-diyl bis(O,O-diisobutyl
phosphorodithioate)s (ADBDiBPDT) for the extraction of palladium(II) from precious
metals was carried out from 1.0 M chloride solution at pH 3 in 1,2-dichloroethane
through 1: 2 palladium(II) complex [54]. Carbon adsorbents like LKAU-4, LKAU-7
and BAU were studied for the extraction of palladium(II) from acidic medium [55]. 4-
Octylphenylamine, decyl isonicotiniate, decyl nicotiniate, decyl 2-hydroxyethyl
sulphide and its analog with partly fluorinated alkyl group were used for palladium(II)
extraction from 3M HCl [56]. Solid phase extraction (SPE) anion exchange cartridges
like Oasis MAX, Isolute SAX and Isolute NH2 was used commercially for the
separation of palladium(II) from aqueous chloride media [57]. The separation of
Pd(II) from the PGMs with HCl media was achieved by using trioctylamine (TOA)in
kerosene [58]. Solvent extraction of palladium(II) with various ketones in
nitrobenzene from nitric acid medium was investigated [59]. Methylalkylketones,
such as 2-octanone, 2-nonanone, 2-undecanone, 2-tridecanone, and ketones containing
symmetrical alkyl configuration, such as 5-nonanone, 5-decanone, 5-undecanone, and
6-undecanone exhibited significant extraction of palladium(II). The extraction
mechanism of Pd(II) from HNO3 or HCIO4 solution with N,N'-bis[l-phenyl-3-methyl-
5-hydroxypyrazole-4-benzylidenyl]-1,3-propylene diamine was studied [60].
Separation palladium(II) and platinum(IV) from the loaded Alamine 336 solution was
examined as a function of the concentration of stripping agents. Platinum group
metals are frequently used in the automobile catalysts, cancer therapy and space
material. Therefore their recovery has great importance hence solvent extraction of
palladium(II) was achieved from the HNO3, HCl and H2SO4 media by toluene solution
of Cyanex 923 [61]. The solvent extraction separation and recovery of Pd(II) from
HCl leach liquors of spent automobile catalyst employing precipitation and liquid-
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 62
liquid extraction methods was developed by tri-n-butyl phosphate (TBP) and Aliquat
336 [62]. Solvent extraction system with 1,2-bis(2-methoxyethylthio) benzene for the
selective separation of palladium(II) from secondary raw materials was developed
[63] and was further adopted for an industrial recovery of palladium(II) from
oxidising leach solutions gained from automotive catalysts. Palladium(II) was
extracted by bis(2-ethylhexy1) sulphoxide (BESO) over a wide range of acidity, and
BESO was shown to have a strong extraction ability toward it [64]. Solvent extraction
of palladium(II) was investigated with N,N-dioctylglycine in toluene from acidic
aqueous chloride media [65]. The chloroform extraction of Pd(II) from H2SO4 in
presence of potassium ethyl xanthate has been studied and it was observed that
palladium(II) was completely extracted [66]. N,N,N',N ' -tetra-n-octylethylenediamine,
N,N-di-n-octyl-2-(aminomethyl)pyridine, Alamine 336, and Aliquat 336 dissolved in
isodecanol-benzene were used to extract palladium(II) from a chloride medium [67].
The extraction behavior of (RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-
1-yl- methyl)-pentan-3-ol with respect to palladium(II) were studied, it was found that
palladium(II) was efficiently extracted by the reagent from 0.1–6 M HCl [68]. Di-(2-
ethylhexyl) thiophosphoric acid (DEHTPA) in kerosene was used for solvent
extraction of palladium(II) from HCl media. The back-extraction of palladium(II)
from organic phase by different stripping reagents [69]. The reagent 1-phenyl-3-
methyl-4-benzoyl-5-pyrazolone at 60C was developed the separation method of
palladium(II) in molten solvent extraction. It was observed that increase in
temperature favor the reaction [70].
N, N, N’, N’-tetrakis[2-pyridyl-methyl]-1,2-ethylenediamine (TPEN).
N,N,N’,N’- tetrakis[4-(2-butyloxy)- 2-pyridyl-methyl ]-1,2-ethylenediamine (TBPEN)
and N,N,N’,N’- tetrakis (2-quinolinylmethyl)-1,2-ethylenediamine (TQEN) was used
for solvent extraction of Pd(II) in the acidic medium [71]. Pd(II) was separated by
using by bulk liquid membranes during electrodialysis. Method showed that an
effective separation of palladium(II) was achieved in the presence of an excess of the
carrier [72]. Cloud point extraction (CPE) in association with thermal lens
spectrometry (TLS) developed for determination of palladium(II) by using Triton X-
114 [73]. The method of extraction was used for determination of palladium(II) in
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 63
water sample. Activated carbon was chemically modified with ethyl-3-(2-
aminoethylamino)-2-chlorobut-2-enoate was applied for selective solid-phase
extraction of trace palladium(II) [74].
There is no report on the extraction and separation of palladium(II) from
salicylate medium by 4-heptylaminopyridine (4-HAP). The superiority of presently
employed method was also compared with other reported methods (Table 1). The aim
of the present work is to develop a simple, efficient, and environmentally friendly
extraction process for the separation and recovery of palladium(II) from salicylate
medium. The effect of pertinent parameters including pH, weak organic acid
concentration, extractant concentration, time, diluents, stripping agents, and diverse
ions as well as binary and ternary separation on palladium(II) extraction have been
investigated to obtain the optimum extraction conditions.
Table 1 Literature of the previously reported solvent extraction method for Pd(II)
System Aqueous
Phase
Organic
Phase
Special Feature Ref.
Fullerene black/ trioctylamine HCl Toluene Fullerene black
impregnated
with
trioctylamine
effectively
recovers
palladium(II)
from HCl
15
N-Benzoyl-N’,N’-
diethylthiourea
NaCl Chloroform Stoichiometry
of complex
was 1: 2
16
Cyanex 921 HCl Toluene Separation of
Pd(II) from
platinum group
metals
Recovery of
palladium(II)
from spent
catalysts
17
Alamine 336 HCl Toluene Separation of
palladium(II)
and
platinum(IV)
18
Bis (2,4,4-trimethylpenty) - Chloroform The separation 19
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 64
phosphinodithioic acid of
palladium(II)
and
platinum(II)
based on the
kinetic effect is
proposed
Palladium(II)
selectively
extracted into
chloroform
N,N-Dimethyldithio-
carbamoylethoxy substituted
calix [ 4 ] arene
- Chloroform Effective
extractant for
transferring
palladium(II)
from an
aqueous to a
chloroform
phase
20
Tri-n-octylamine (TOA) HCl TOA
molecules act
on the
extraction of
precious metal
21
4-Alkylphenylamines HCl Benzene &
Toluene
Adsorb at the
hydrocarbon /
water interface
22
1-[2-(2,4-dichloro phenyl)-4-
propyl-1,3-dioxolan- 2-
ylmethyl] -1 H-1, 2, 4-triazole
HCl Toluene The extraction
follows the
anion-
exchange
mechanism
Extraction of
precious metals
was also
carried out
23
N,N,N’,N’-tetra-
(2-ethylhexyl)
thiodiglycolamide
(T(2EH)TDGA) N,N,N’,N’-
tetra-(2-ethylhexyl) dithio
diglycolamide (DTDGA)
0.1 M
HNO3
n-Dodecane Palladium(II)
ion exhibiting
2 : 1
stoichiometry
24
2,2’-Dithiodianiline (DTDA) pH =3.0 Iso-butyl
methyl
ketone
The tolerance
limit for many
cations and
anions have
been
determined in
synthetic
25
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 65
mixtures,
catalyst and
alloy samples.
Dicyclohexyl-18-crown-6
(DC18C6)
HCl Chloroform Extraction
based on ion-
pair formation
of
palladium(II)
thiocyanate
26
Calix[4]arene HNO3 Chloroform Selective
extraction of
palladium(II)
27
1-Benzoyl-
3-[6-(3-benzoyl-thioureido)-
hexyl]-thiourea
HNO3 1,2-
Dichloro-
ethane
The increasing
number of
thioamide
groups in the
molecule,
increases its
extraction
efficiency
towards
palladium(II).
28
N,N’-dimethyl-N,N’-
diphenyltetradecylmalonamide
(DMDPHTDMA)
HCl 1,2-
Dichloro-
ethane
Easily
separation of
palladium(II)
from base
metals
29
N,N-diethyl-N’-
benzoylthiourea
HNO3 Interference of
other elements
impairs the
determination
Alkaline and
earth alkaline
metals as well
as iron can be
separated
30
Cyanex 923 HCl
4-5 M
Toluene Palladium(II)
was stripped
with 1:1 HCl +
HClO4
Separation of
palladium(II)
from
platinum(IV)
was observed
31
Aliquat 336 Salicylate
pH = 5.0
Xylene Separation of
palladium(II)
from base
metals
32
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 66
Analysis of
catalyst and
Ore
Bisacylated
Diethylenetriamine
HCl Toluene Separated from
associate
ferrous and
base metals
33
N,N-Di(2-ethylhexyl) amino
methyl quiniline (DEQ)
HCl Toluene Palladium(II)
extracted as 1:
1 complex
34
7-Octyltheophylline HCl Ethanol 100%
Stripping of
palladium(II)
with 1M
ammonia
solution
35
Cyphos IL 101 HCl Toluene Very efficient
and fast
extractant
Stripping of
palladium(II)
from 0.5 M
ammonia
solution
36
Aliquat 336 HCl Thiourea is an
efficient
stripping
reagent for
palladium(II)
37
Quinoline-2-carboxalde- hyde
2-pyridyl-hydrazone
Dichloro-
methane
Ligand formed
1:1 complex
38
2-Ethylhexyl phosphonic
acid mono-2-ethylhexyl ester
(PC-88A)
0.7-2.0 M
HCl-
HClO4
Toluene Palladium(II)
and
Platinum(IV)
was
quantitatively
separated
Analysis of
palladium(II)
in real sample
39
p-(1,1,3,3-Tetramethyl butyl)
phenyl hydrogen [N,N-di(2-
ethylhexyl) amino methyl
phosphonate
Toluene The recovery
and
purification of
precious metals
from various
materials such
as scraps
40
1,2-Bis(tert-hexylthio) ethane HCl Toluene Palladium(II)
extracted as 1:1
41
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 67
t-BHTE
1-Octyltheobromine HCl Toluene Stripping of
palladium(II)
was performed
over 60% by
ammonia or
thiourea
42
Hexadecylpyridinium bromide
(HDPB)
HBr Chloroform Average
recovery of
palladium(II)
was 99% with
an RSD of
0.95%
43
Tri-n-octylamine (TOA) HCl Xylene HNO3 was
used as
stripping agent
44
Trioctyl ammonium
bis(trifluoro methane sulfonyl)
amide ([TOAH][NTf2])
HCl Back-extracted
from the ionic
liquid mixture
with nitric acid
solution
45
Octyl(phenyl)-N,N-
Diisobutylcarbamoyl
methylphosphine
oxide
HNO3 n-Dodecane Solvent
extraction was
demonstrated
by adding
oxalic acid.
46
Dibenzo-18-crown-6
(DB18C6) and cis-syncis-
dicyclohexyl -18-crown-6
(DCH18C6)
HCl Dichloro-
ethane Extraction of
palladium(II)
in the presence
of KSCN.
47
Calix[4]arene,
thiacalix[4]arenes
HNO3
pH = 3
Combined
extraction of
palladium(II)
and silver(I)
from alkaline
solutions
Selective
extraction of
palladium(II)
from fission
alloy
48
N,N’-dimethyl-N,N’-di-n-
octyl-thiodiglycolamide
(MOTDA)
HCl n- Dodecane
& 2-ethyl-
hexanol
Nearly 100%
palladium(II)
was extracted
with MOTDA
49
Dinonyl naphthalene sulfonic
acid (HDNNS)
HON3 Kerosene
&
Dodecane
The influence
of the
concentration
of nitric acid,
50
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 68
HDNNS, and
thiamacrocycle
were studied
Di-(2-ethylhexyl)
thiophosphoric acid
(DEHTPA)
HCl n-Hexane Distribution
was studied
between
aqueous and
resin phase
51
4-(n-octyl)diethylene triamine HCl Metals
recovered were
quantitatively
eluted with 1
M HCl solution
52
[5-(4-dimethyl
aminebenzylidene) rhodanine
pH = 2.4 Isobutyl
ketone
Stripping was
performed with
3.0 M
sulphuric acid.
53
Alkane-1, ω-diyl Bis(O,O-
Diisobutyl
phiosphorodithioate)s
(ADBDiBPDT)
pH = 3.0 1,2-
Dichloro
ethane
Extraction 1: 2
or 1: 1
stoichiometry
was observed
54
LKAU-4, LKAU-7, and BAU HCl More than 60%
palladium(II)
was recovered
55
4-Octylphenylamine HCl 3.0M Toluene Extraction rate
increases with
ester
56
Isolute-SAX, OASIS-MAX,
Isolute-NH2
NaCl Extraction
efficiency
higher than
95%
57
Trioctylamine (TOA) HCI Kerosene Selective
transport; and
recovery of
platinum group
metals
58
2-Tridecanone HNO3 Nitro-
benzene Organic phase
was back
extracted with
thiourea
59
N,N'-bis[l-phenyl-3-methyl-5-
hydroxypyrazole-
4-benzylidenyl]-1,3-propylene
diamine (H,A)
HNO3
HCIO4
Chloroform
& Toluene
Distribution
ratio decreases
with acidity
and chloride
ion
concentration
60
Cyanex 923 HNO3 Toluene Palladium(II)
recovered from
spent
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 69
commercial
materials.
Mutual
separation of
palladium(II),
platinum(IV),
rhodium(III)
and associated
metal ions
61
Tri-n-butyl phosphate (TBP) HCl Kerosene Selective
separation of
palladium(II)
from other
metals
Separation and
recovery of
palladium(II)
from spent
automobile
catalyst
62
1,2-Bis(2-methoxyethylthio)-
benzene
1,2-
Dichloro-
benzene
Extract more
than 98% of
the
palladium(II)
0.5M thiourea
in 0.1 M
hydrochloric
acid used as
strippant
63
Bis(Zethylhexy1) sulphoxide
(BBSO)
HNO3
8 M
Toluene The high
extraction for
palladium(II)
recovery
64
N,N-dioctylglycine HCl/
NaCl
Toluene Extracted as a
1:2 metal:
reagent
65
Potassium ethyl xanthate H2SO4
10 M
Chloroform Extraction of
various
elements as
ethyl xanthate
complexes
from H2SO4
and HCl
66
Alamine 336, and Aliquat 336 pH Isodecanol-
benzene
Diamine
extractants
were superior
to a
monoamine
extractant for
67
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 70
the extraction
of
palladium(II)
(RS)-1-(4-chlorophenyl)-4,4-
dimethyl-3-(1H-1,2,4-triazol-
1-yl-methyl)-pentan-3-ol
HCl
0.1–6.0M
Chloroform Selective
separation of
palladium(II)
and copper(II)
from Fe(III),
Co(II) and
Ni(II)
68
Di-(2-ethylhexyl)
thiophosphoric acid
(DEHTPA or HL
HCl Kerosene Selective for
palladium(II)
against Fe(III),
Zn(II), Cu(II),
Pt(IV) and
Rh(III)
69
1-Phenyl-3-methyl-4-
benzoyl-5-pyrazone (PMBP)
pH = 1.0-
3.5
Paraffin
wax
The extraction
efficiency was
up to 97%
70
N,N’,N’-tetrakis[2-pyridyl-
methyl]-1,2-
ethylenediamine
pH = 1 Exhibited
selective
extraction of
palladium(II)
71
Diphenylthiourea/c di-o-
tolylthiourea
1,2-
Dichloro-
ethane
Effective
separation of
platinum(IV)
from
palladium(II)
was achieved
72
Triton X-114 pH = 4.0 Determination
of trace
amounts of
Pd(II) in spiked
water sample
73
Ethyl-3-(2-aminoethylamino)-
2-chlorobut-2-enoate
pH = 1 Many common
ions do not
interfere
The method was
validated for
determination of
ions in actual
samples
74
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 71
3.3 Experimental
3.3.1 Apparatus
UV/VIS Spectrophotometer model-Optizen α (mecasys Co., Ltd/made in South
Korea) with 1cm quartz cell was used for absorbance measurements and pH
measurements were carried out with an Elico Digital pH meter Model LI-120 with a
combined glass electrode.
3.3.2 Reagents
A Stock solution of palladium(II) was prepared by dissolving appropriate
amounts of analytical grade Palladium chloride hydrate (Johnson Matthey, UK) in
analar hydrochloric acid (1 M) and diluting to 250 mL with distilled water. 4-
Heptylaminopyridine was synthesized by reacting 4-aminopyridine with 1-
bromoheptane in the presence of base Sodium amide (NaNH2) in dry THF [75] and its
solutions were prepared in xylene. All the chemicals used were of analytical reagent
grade, were supplied from sigma (St. Loius, Mo, USA). Doubly distilled water was
used throughout.
3.3.3 Solvent extraction procedure
In all the extraction studies, aqueous (Pd(II) ion in appropriate concentration
and 0.04 M sodium salicylate, pH was adjusted to 0.5) and organic (0.05 M 4-HAP in
xylene) phases in a ratio of 2.5:1 were shaken at room temperature in glass stoppered
separating funnel for 5 min. After phase disengagement, the aqueous phase was
separated, and loaded organic phase was stripped with 6.0 M ammonia (2 × 10 mL).
The concentration of palladium(II) from stripped solution was determined
spectrophotometrically using dithizone method [76].
3.4 Results and discussion
3.4.1 Influence of pH on the extraction of palladium(II)
The effect of the pH in the range 0.1–10 on the extraction of palladium(II) was
carried out using 0.05 M 4-HAP in xylene. The amount of palladium(II) taken is 200
μg and aqueous–organic volume ratio of 2.5:1 was maintained. As can be seen in (Fig.
1), as the pH increases from 0.3 to 1.0, the percentage extraction increases. As the pH
increases above 1.0, the percentage of extraction decreases. This is because of the ion-
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 72
pair complex may be less stable at higher pH. Therefore, pH 0.5 was selected for the
further study (Table 2).
3.4.2 Effect of 4-HAP concentration on the extraction of palladium(II)
The extraction behavior of palladium(II) was studied with an extractant 4-HAP
concentration range of 0.01–0.15 M, at a pH of 0.5, and with 0.04 M sodium
salicylate. The quantitative extraction of palladium(II) was achieved in the
concentration range of 0.04–0.07 M 4-HAP (Table 3). Further increase in
concentration of 4-HAP, there was decrease in percentage extraction of palladium(II),
this is because of formation of stable RR’NH2+sal- species in which sal- will not be
replaced by Pd(sal)3- species. In order to ensure the complete extraction of
palladium(II) from the aqueous phase, 0.05 M 4-HAP is recommended for the general
extraction procedure (Fig. 2).
3.4.3 Effect of organic acid concentration on the extraction of Pd(II)
The extraction of 200 μg of palladium(II) was carried out from different weak
carboxylic acids like sodium succinate, sodium malonate, sodium ascorbate, and
sodium salicylate at pH 0.5 and 0.05 M 4-HAP in xylene. It is apparent from the
(Table 4) that the extraction of palladium(II) reaches maximum (99.5%) with
salicylate media in the concentration 0.03–0.05 M. This showed that the ion-pair
complex of palladium(II) was found to be quantitative in salicylate media in the range
of 0.03–0.05 M. As the concentration of sodium salicylate increases above 0.05 M, the
percentage extraction of palladium(II) decreases. Therefore, 0.04 M sodium salicylate
was used for further extraction processes. The extraction was incomplete in sodium
succinate (70.2%), sodium malonate (62.2%), and sodium ascorbate (28.5%) due to
the lack of ion-pair formation (Fig. 3).
3.4.4 Effect of diluents on the extraction of palladium(II)
The 200 μg of palladium(II) in 0.04 M sodium salicylate at pH 0.5 was
contacted with 10 mL of 0.05 M 4-HAP dissolved in different diluents. (Table 5)
showed the percentage extraction of palladium(II) loaded 4-HAP in different diluents.
It was found that 0.05 M 4-HAP solution in carbon tetrachloride, amyl alcohol,
toluene, and xylene provides quantitative extraction of palladium(II). The extraction
of palladium(II) was found to be incomplete in methyl isobutyl ketone (88.5%), n-
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 73
butyl alcohol (60.0%), kerosene (48.5%), 1,2-dichloroethane (45.7%), and chloroform
(20.0%) (Fig. 4). Xylene was preferred as a diluent for further extraction procedures,
because it provides a quicker phase separation with high distribution of the ion-pair
complex.
3.4.5 Influence of contact time on extraction of Pd(II)
The effect of contact time on extraction of palladium(II) in 0.04 M sodium
salicylate medium at pH 0.5, keeping an aq:org ratio of 2.5:1 and a 4-HAP
concentration of 0.05 M was examined in the range of 5 s–30 min (Table 6). The
extraction was found to be quantitative over the period of 4 min (Fig. 5). But to ensure
the complete extraction of palladium(II), 5 min equilibration time was recommended.
3.4.6 Stripping of palladium(II) from the loaded organic phase
Stripping of palladium(II) was carried out using different stripping reagents.
Stripping is the reverse of extraction. When the extraction of metal is carried out from
acidic medium, then back extraction is generally possible from the basic medium in
order to dissociate the ion-pair complex. The most efficient stripping of palladium(II)
from loaded organic phase was achieved with 4–10 M ammonia and ammonia buffer
pH 10. Among these two, ammonia solution is more preferred than ammonia buffer
(pH 10) solution to evaporate the aqueous phase more easily. The results obtained for
various stripping reagents examined are presented in (Table 7).
3.4.7 Loading capacity of the 4-HAP
Loading capacity of 4-HAP in xylene was determined by contacting
palladium(II) in 0.04 M sodium salicylate at a fixed aqueous to organic phase ratio
2.5:1. After equilibrium and phase separation, the same organic phase was used again
for the extraction of fresh feed solution of definite amount concentration of
palladium(II) (Table 8). The extraction of palladium(II) repeated till no further
extraction was found in the organic phase. The concentration of palladium(II) in the
organic phase of 4-HAP was found to be 2 mg (Fig. 6).
3.4.8 Effect of aqueous to organic volume ratio
In order to obtain a reliable, reproducible results and for a high extraction
efficiency, the aqueous:organic volume ratio is an another important parameter in
liquid–liquid extraction. The results of contacting different volume ratios of aqueous
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 74
to organic phases have been studied. The results indicate that a preferred aqueous/
organic (A/O) phase ratio in this study was found to be 4:1 or less. This is evident
from the sharp increase in the separation efficiency as well as the distribution of
palladium(II) when the phase ratio (A/O) changed from 25:1 to 4:1. This may simply
be due to unavailability of reagent for the extraction at higher phase ratio, so a
crowding effect occurs at a low phase ratio. However, in the recommended procedure
the phase ratio is maintained at 2.5:1 so as to avoid the large consumption of sodium
salicylate (Table 9).
3.4.9 Mechanism of the ion-pair complex
Attempts were made to ascertain the nature of the extracted species using log
D–log C plots. The graphs of log D[Pd(II)] against log C[4-HAP] at a fixed sodium
salicylate concentration (0.04 M) were found to be linear, having slopes of 0.88 and
0.74 at pH 2 and 3, respectively (Fig. 7). Also, plots of log D[Pd(II)] against log
C[salicylate] at fixed 4-heptylaminopyridine concentration (0.05 M) were linear and the
slope values were found to be 2.70 and 2.75 at pH 3 and 4, respectively (Fig. 8). The
probable composition of the extracted species was calculated to be 1 : 3 : 1 (metal :
acid : extractant).
In the mechanism of extraction first step is protonation of 4-HAP to form the
cationic species as RR’NH2+ and second step is formation of anionic species by
combining salicylate with Pd(II) as [Pd(Sal)3]-aq and both of these cationic and anionic
species associate to form an ion-association of type [RR’NH2+Pd(Sal)3
-]org
I] Probable mechanism of extraction:
RR'NHorg + H+aq RR'NH2
+
PdCl2 aq + Cl-aq PdCl3
- aq
PdCl3-
aq+ 3Hsal aq
[Pd (sal)3]-
aq + 3H+
RR'NH2+
org + [Pd (sal)3]-
aq [RR'NH2+Pd (sal)3
-] org
II] Probable mechanism of stripping:
When organic phase was back stripped with 6.0 M NH3 solution, there is
formation of [Pd(NH3)2(H2O)2]2+ species in the stripped solution [77].
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 75
RR'NHorg [RR'NH2+Pd (sal)3
-] org+ 2NH4OH + [Pd(NH3)2(H2O)2]
2+aq
3 Salicylate-
aq+ + H+
3.5 Applications
3.5.1 Effect of diverse ions
In order to evaluate the suitability of the proposed method for extraction of
palladium(II), the effect of some diverse ions was studied by adding different amounts
of diverse ions to 200 µg of palladium(II) with 4-HAP (10 mL 0.05 M) in 0.04 M
sodium salicylate. An error less than ± 2% was considered to be tolerable (Table 10).
The selectivity of proposed method was enhanced by masking the tolerable cations
with a suitable masking agent.
3.5.2 Separation of palladium(II) from binary mixtures
The separation of palladium(II) from the associated metal ions has been
achieved under the optimum separation conditions in binary mixtures in binary
mixtures. At this condition palladium(II) is extracted quantitatively leaving Fe(III),
Ni(II), Co(II), Cu(II), Pt(IV), Os(VIII), Ir(III), Ru(III), Au(III), Rh(III), Hg(II), Zn(II),
Pb(II), Cd(II), Bi(III), Te(IV), and Ag(I) in the aqueous phase from which they are
determined spectrophotometrically by standard methods (Table 11). palladium(II)
from the organic phase was stripped and estimated spectrophotometrically by applying
dithizone method.
3.5.3 Separation of palladium(II) from ternary mixtures
palladium(II) selectively extracted from ternary mixtures. palladium(II) is one
of the platinum group metals (PGMs), and therefore, palladium(II) was separated from
Ag(I), Au(III); Ru(III), Rh(III); Ir(III), Pt(IV); Au(III), Pt(IV); and Os(VIII), Au(III).
In this case, the Os (VIII) is masked by the suitable masking agent (Table 12). All the
PGMs are not extracted with 10 mL 4-HAP in xylene at 0.04 M sodium salicylate and
pH 0.5. palladium(II) was also isolated from Cu(II), Co(II); Fe(III), Ag(I); Zn(II),
Cu(II); Ni(II), Co(II); Fe(III), Cu(II); and Se(IV), Te(IV).
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 76
3.5.4 Analysis of palladium(II) from a synthetic mixture corresponding to the
composition of alloy
To ascertain the selectivity of the proposed method, it was successfully applied
for the determination of palladium(II) in alloys from salicylate media at pH 0.5. The
real samples were not available; hence the synthetic mixtures were prepared
corresponding to the composition of the alloy. The results of the analysis are reported
in (Table 13).
3.5.5 Analysis of palladium(II) in catalyst
The proposed method is applicable for the determination of palladium(II) in
various catalysts. A known amount of the catalyst was dissolved in a mixture of 9 mL
and 3 mL of concentrated hydrochloric and nitric acid, respectively. The solution of
catalyst is then heated with concentrated hydrochloric acid to remove the oxides of
nitrogen. The residue was dissolved in 10 mL of 1.0 M hydrochloric acid and filtered
to remove carbon or barium sulfate. The residue was washed with dilute HCl. The
filtrate and washings were collected and diluted with water in a standard volumetric
flask. An aliquot of the sample solution was taken, and palladium(II) was determined
as per the general procedure. The results of the analysis are collected in (Table 14).
3.5.6 Determination of palladium(II) in different water samples
In order to investigate the accuracy and applicability of this method, real
samples were analyzed. For the sample preparation, 200 µg of palladium(II) were
spiked into the solutions and the results of recovery are shown in (Table 15).
3.6 Conclusions
The present investigations highlight that 4-Heptylaminopyridine is a useful
extractant for extraction of palladium(II) and also for their separation from
most of the commonly associated metal ions.
The separations can be accomplished at room temperature.
The stripping agent used for separation is simple and convenient for further
processing of solutions.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 77
In the earlier methods employed for extraction of palladium(II) the medium
used is mineral acid, but in our proposed method we used a weak acid as a
medium for extraction, in that sense our method is greener than the earlier.
The developed conditions of extraction have been successfully extended to
recover palladium(II) from synthetic mixture, alloys, catalysts, water samples,
and binary and ternary metal ion mixtures.
The method developed for the extraction of palladium(II) is very simple,
selective, rapid, and cost effective for the separation and determination of
palladium(II).
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 78
Table 2 Effect of pH on the extraction of palladium(II)
Palladium(II) = 200 µg Aq. : Org. = 2.5:1
Org. = 0.05 M 4-HAP in xylene (10 mL) Sodium salicylate = 0.04 M
Strippant = 6.0 M Ammonia (2× 10 mL)
pH Percentage extraction, (% E) Distribution ratio, (D)
0.05 80.2 10.12
0.1 96.5 68.92
0.3 100 ∞
0.5* 100 ∞
0.7 100 ∞
1.0 100 ∞
1.5 85.1 14.27
1.7 80.0 10.0
2.0 79.4 9.63
3.0 62.8 4.22
4.0 56.5 3.24
5.0 42.8 1.87
6.0 43.1 1.89
7.0 28.5 0.99
8.0 22.8 0.73
9.0 8.57 0.23
10.0 8.57 0.23
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 79
Table 3 Effect of 4-HAP concentration on the extraction of palladium(II)
Palladium(II) = 200 µg pH = 0.5
Strippant = 6.0 M Ammonia (2× 10 mL) Sodium salicylate = 0.04 M
Aq.: Org. = 2.5: 1
4-HAP (M) Percentage extraction, (% E) Distribution ratio, (D)
0.01 41.7 1.78
0.02 73.4 6.90
0.03 95.1 48.94
0.04 100 ∞
0.05* 100 ∞
0.06 100 ∞
0.07 100 ∞
0.08 98.5 172.32
0.09 96.5 70.38
0.10 94.5 43.54
0.11 93.7 37.24
0.12 91.7 27.65
0.13 91.1 25.71
0.14 89.1 20.52
0.15 87.7 17.84
0.16 86.0 15.35
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 80
Table 4 Effect of organic acid concentration on the extraction of Pd(II)
Pd(II) = 200 µg pH = 0.5
Org. = 0.05 M 4-HAP in xylene (10 mL) Aq.: Org. = 2.5:1
Strippant = 6.0 M Ammonia (2× 10 mL)
Weak organic
acid
concentration,
(M)
Sodium salicylate Sodium
succinate
Sodium
malonate
Sodium
ascorbate
% Ea Db % Ea Db % Ea Db % Ea Db
0.005 52.0 2.70 37.7 1.51 45.4 2.07 24.0 0.78
0.01 66.0 4.85 39.1 1.60 46.8 2.19 24.8 0.82
0.02 88.2 18.68 58.0 3.45 60.2 3.78 32.2 1.18
0.03 95.7 55.63 70.2 5.88 60.2 3.78 25.1 0.83
0.035 100 ∞ 69.4 5.66 61.1 3.92 27.1 0.92
0.04* 100 ∞ 67.1 5.09 62.2 4.11 28.5 0.99
0.045 100 ∞ 65.7 4.78 61.4 3.97 27.7 0.95
0.05 100 ∞ 64.5 5.54 61.7 4.02 26.2 0.88
0.06 80.0 10 59.7 3.70 58.8 3.56 27.4 0.94
0.07 61.4 3.97 70.0 5.83 81.4 10.94 23.7 0.77
0.08 40.8 1.72 50.5 2.55 74.2 7.18 22.8 0.73
0.09 20.0 0.62 55.1 3.06 54.8 3.03 21.1 0.66
0.1 5.71 0.15 52.8 2.79 53.7 2.89 19.4 0.60
a = Percentage extraction, b = Distribution ratio
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 81
Table 5 Effect of diluents on the extraction of palladium(II)
Palladium(II) = 200 µg pH = 0.5
Org. = 0.05 M 4-HAP in xylene (10 mL) Sodium salicylate = 0.04 M
Strippant = 6.0 M Ammonia (2× 10 mL) Aq.: Org. = 2.5:1
Solvents Dielectric constant Percentage
extraction, (%E)
Distribution ratio,
(D)
Xylene* 2.30 100 ∞
Toluene 2.38 100 ∞
Amyl alcohol 13.90 100 ∞
Carbon tetrachloride 2.24 100 ∞
Methyl isobutyl
ketone
13.11 88.5 19.23
n-Butyl alcohol 17.51 60.0 3.75
Kerosene 1.8 48.5 2.35
1,2-Dichloroethane 1.25 45.7 2.10
Chloroform 4.81 20.0 0.625
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 82
Table 6 Effect of contact time on the extraction of palladium(II)
Palladium(II) = 200 µg pH = 0.5
Org. = 0.05 M 4-HAP in xylene (10 mL) Sodium salicylate = 0.04 M
Strippant = 6.0 M Ammonia (2× 10 mL) Aq.: Org. = 2.5:1
Contact time, min Percentage extraction, (% E) Distribution ratio, (D)
0.05 28.0 0.97
0.15 40.5 1.70
0.30 53.4 2.86
0.45 61.4 3.97
1 73.1 6.79
2 75.4 7.66
3 92.8 32.2
4 100 ∞
5* 100 ∞
6 100 ∞
7 100 ∞
8 100 ∞
9 100 ∞
10 100 ∞
15 100 ∞
20 70.0 5.83
25 34.2 1.29
30 30.0 1.07
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 83
Table 7 Stripping of palladium(II) from the loaded organic phase
Palladium(II) = 200 µg pH = 0.5
Org. = 0.05 M 4-HAP in xylene (10 mL) Salicylate = 0.04 M
Aqueous : Organic = 2.5:1
Strippant,
M
Ammonia HCl Acetic acid H2SO4 NaOH
%Ea Db %Ea Db %Ea Db %Ea Db %Ea Db
1 52.5 2.76 18.8 0.57 5.14 0.13 5.42 0.14 12.5 0.35
2 68.8 5.51 40.2 1.68 6.85 0.18 5.71 0.15 13.1 0.37
3 87.1 16.86 48.0 2.30 9.71 0.26 7.14 0.19 14.2 0.41
4 100 ∞ 58.8 3.56 10.0 0.27 7.71 0.20
No Stripping
5 100 ∞ 64.8 4.60 9.42 0.25 4.28 0.11
6* 100 ∞ 70.5 5.97 12.2 0.34
No Stripping
7 100 ∞ 77.7 8.71 16.0 0.47
8 100 ∞ 80.5 10.32 17.1 0.51
9 100 ∞ 82.8 12.03 19.1 0.59
10 100 ∞ 84.8 13.94 20.8 0.65
aPercentage Extraction, (%E) bDistrbution ratio, (D)
*Recommended for general extraction procedure
%E D
Ammonia buffer (pH = 10) 100 ∞
Acetate buffer (pH = 4.7) 35.4 1.36
Water 10.2 0.28
HNO3 No Stripping
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 84
Table 8 Loading capacity of the 4-HAP
pH = 0.5
Org. = 0.05 M 4-HAP in xylene (10 mL) Salicylate = 0.04 M
Strippant = 6.0 M Ammonia (2× 10 mL) Aqueous : Organic = 2.5:1
Palladium(II), µg Percentage extraction, (% E) Distribution ratio, (D)
100 100 ∞
200* 100 ∞
400 100 ∞
800 100 ∞
1000 100 ∞
1500 100 ∞
2000 100 ∞
2400 95.7 55.63
3000 91.4 26.56
4000 87.1 16.87
5000 82.0 11.38
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 85
Table 9 Influence of aqueous to organic volume ratio on extraction of Pd(II)
Palladium(II) = 200 µg pH = 0.5
Org. = 0.05 M 4-HAP in xylene (10 mL) Sodium salicylate = 0.04 M
Strippant = 6.0 M Ammonia (2× 10 mL)
Aq: Org Percentage extraction, (%
E)
Distribution ratio, (D)
10:10 100 ∞
20:10 100 ∞
25:10* 100 ∞
30:10 100 ∞
35:10 100 ∞
40:10 100 ∞
50:10 97.7 106.19
70:10 95.4 51.84
100:10 48.5 2.35
150:10 42.0 1.81
200:10 34.2 1.29
250:10 28.5 0.99
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 86
Table 10 Effect of diverse ions on the extraction of palladium(II)
Amount tolerated (mg) Diverse ion added
25 Te(IV)
15 Zn(II), Hg(II), chloride
10 Cu(II), Ni(II), Co(II), Cd(II), Bi(III), Sb(III), Mg(II), Sn(II),
Pb(II)b, bromide, citrate, nitrate
5 fluoride, malonate, acetate, oxalate
Cr(VI), Fe(III)a, Fe(II)a, Se(IV)a, Ca(II)c, In(III), Tl(I), U(VI)a
3 V(V)a, Au(III)e, Pt(IV)d, nitrate, succinate
2 tartarate, Ga(III)d, Os(VIII)f, Mo(II)d, W(VI)a, Ru(III)f, Rh(III)f
1 EDTA, sulphate, iodide
0 thiourea, thiosulphate, ascorbate
aMasked with 3 mg fluoride
bMasked with 3 mg acetate
cMasked with 7 mg citrate
dMasked with 3 mg oxalate
eMasked with 7 mg bromide
fMasked with 12 mg chloride
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 87
Table 11 Separation of palladium(II) from binary mixtures
Metal Ion Amount taken,
µg
Average
recovery (%)a
Chromogenic
ligand
Reference
Pd(II)
Fe(III)
200
60
99.8
98.5
Thiocyanate
76
Pd(II)
Ni(II)
200
40
99.3
99.7
DMG
76
Pd(II)
Co(II)
200
300
99.3
99.5
Thiocyanate
76
Pd(II)
Cu(II)
200
300
99.5
99.3
Cuproine
76
Pd(II)
Pt(IV)
200
300
99.3
99.6
Stannous chloride
76
Pd(II)
Os(VIII)b
200
300
99.3
99.6
Thiourea
78
Pd(II)
Ir(III)
200
80
99.9
99.7
Stannous chloride
hydrobromic acid
76
Pd(II)
Ru(III)
200
200
99.9
99.7
Thiourea
78
Pd(II)
Au(III)
200
200
99.8
98.9
Stannous chloride
78
Pd(II)
Rh(III)
200
200
98.8
99.5
Potassium iodide
76
Pd(II)
Hg(II)
200
100
99.8
98.4
PAN
79
Pd(II)
Zn(II)
200
60
99.9
99.2
PAR
79
Pd(II)
Pb(II)
200
100
99.9
99.0
PAR
76
Pd(II)
Cd(II)
200
10
99.8
98.9
PAR
79
Pd(II)
Bi(III)
200
300
99.9
99.0
Ascorbic acid +
Potassium iodide
76
Pd(II)
Te(IV)
200
120
99.7
99.4
Bismuthiol II
76
Pd(II)
Ag(I)
200
120
99.9
99.7
Rhodanine
76
aAverage of six determinations bMasked with 12 mg chloride
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 88
Table 12 Separation of palladium(II) from ternary mixtures
Composition of mixture
µg
Percentage recovery of
palladium(II) (% R)* RSD (%)
Pd(II) 200; Se(IV) 200; Te(IV) 120 99.2 0.66
Pd(II) 200; Fe(III) 60; Cu(II) 300 99.6 0.33
Pd(II) 200; Ni(II) 40; Co(II) 300 99.1 0.84
Pd(II) 200; Ag(I) 120; Au(III) 200 98.6 0.40
Pd(II) 200; Ru(III) 200; Rh(III) 200 99.3 0.67
Pd(II) 200; Ir(III) 80; Pt(IV) 300 99.9 0.04
Pd(II) 200; Zn(II) 60; Cu(II) 300 99.7 0.39
Pd(II) 200; Au(III) 200; Pt(IV) 300 99.6 0.45
Pd(II) 200; Fe(III) 60; Ag(I) 120 99.9 0.17
Pd(II) 200; Au(III) 200;
Os(VIII)a300
99.6 0.26
Pd(II) 200; Cu(II) 300; Co(II) 300 99.0 0.71
*Average of five determinations
aMasked with 12 mg chloride
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 89
Table 13 Analysis of palladium(II) in synthetic mixture corresponding to the
composition of alloy
Alloy Composition
(%)
palladium(II)
taken (µg)
Palladium(II)
Found (µg)
Relative
recoverya
(%)
RSD
(%)
White gold Au-75, Pd-10,
Ni-10, Zn-5
10 9.9 99.1 0.84
Jewellery alloy Pd-95.5, Ru-
4.5
95.5 95.1 99.7 0.17
Pd – Cu Pd-60, Cu-40 60 59.7 99.6 0.26
Stibio
palladinite
mineral
Pd-75, Sb-25 75 73.9 98.6 0.8
Oakay
i) Pd-10.5, Pt-
20, Ni-60, V-
9.5
10.5 10.4 99.6 0.45
ii) Pd-18.2,
Pt-18, Ni-54,
V-9.5
18.2 18.0 98.9 0.71
Dental alloy
i) Ag-45, Pd-
50,Pt-2, Au-1
50 49.7 99.5 0.56
ii) Ag-15, Au-
60, Pd-10, Pt-
15
10 9.9 99.8 0.09
iii) Pd-34, Ni-
34,Co-22,
Au-10
34 33.8 99.4 0.37
Solder alloy Pd-30, Pt-10,
Au-60
30 29.8 99.4 0.52
Golden colour
silver alloy
Pd-26, In-21,
Cu-18, Ag-35
26 25.8 99.5 0.49
Pd – Au Pd-50, Au-50 50 49.6 99.3 0.67
Autocatalyst Pd-20, Pt-15,
Rh-50
20 19.9 99.9 0.04
aAverage of five determinations
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 90
Table 14 Analysis of palladium(II) in catalyst
Catalyst Palladium(II)
added (µg)
Palladium(II)
found
by proposed
method (µg)
Relative
recoverya
(%)
RSD
(%)
Pd on BaSO4 (5%) 200 199.66 99.8 0.29
Pd on BaCO3 (5%) 200 199.80 99.9 0.06
Pd on CaCO3 (5%) 200 199.86 99.9 0.04
Pd on Carbon (10%) 200 199.40 99.7 0.33
Pd on Carbon (5%) 200 199.86 99.9 0.05
aAverage of five determinations
Table 15 Determination of palladium(II) in different water samples
Sample palladium(II)
spiked (µg)
palladium(II)
found (µg)
Relative
recoverya
(%)
RSD
(%)
Distilled water 0.00 n.f. - -
200 199.86 99.9 0.04
Tap water 0.00 n.f. - -
200 199.80 99.9 0.06
Waste water 0.00 n.f. - -
200 199.66 99.8 0.29
River water 0.00 n.f. - -
200 199.40 99.7 0.33
aAverage of five determinations n.f. = not found
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 91
Fig. 1 Effect of pH on the extraction of Pd(II)
Condition:
Pd(II) = 200 µg, salicylate = 0.04 M, 4-HAP = 0.05 M in xylene, aq. : org. volume ratio = 2.5
: 1, strippant = 6.0 M NH4OH (2 X 10 mL), shaking time = 5.0 min.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 92
Fig. 2 Effect of 4-HAP concentration on the extraction of Pd(II)
Condition:
Pd(II) = 200 µg, salicylate = 0.04 M, pH = 0.5, aq. : org. volume ratio = 2.5 : 1, strippant =
6.0 M NH4OH (2 X 10 mL), shaking time = 5.0 min.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 93
Fig. 3 Effect of organic acid on the extraction of Pd(II)
Condition:
Pd(II) = 200 µg, 4-HAP = 0.05 M in xylene (10 mL), pH = 0.5, shaking time = 5.0 min.,
strippant = 6.0 M NH4OH (2 X 10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 94
Fig. 4 Effect of diluents on the extraction of Pd(II)
Condition:
Pd(II) = 200 µg, pH = 0.5, salicylate = 0.04 M, 4-HAP = 0.05 M in variable diluents (10 mL),
aq. : org. volume ratio = 2.5 : 1, shaking time = 5.0 min., strippant = 6.0 M NH4OH (2×10
mL)
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 95
Fig. 5 Effect of shaking time on the extraction of Pd(II)
Condition:
Pd(II) = 200 µg, pH = 0.5, salicylate = 0.04 M, 4-HAP = 0.05 M in xylene,
strippant = 6.0 M NH4OH (2×10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 96
Fig. 6 Loading capacity of the 4-HAP
Conditions:
pH = 0.5, salicylate = 0.04 M, 4-HAP = 0.05 M in xylene, aq. : org. volume ratio = 2.5 : 1,
shaking time = 5.0 min., strippant = 6.0 M NH4OH (2×10 mL)
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 97
Fig. 7 log-log plot of distribution ratio Log D[Pd(II)] versus Log C[4-HAP] at fixed salicylate
concentration (0.04 M)
Conditions:
Pd(II) = 200 µg, salicylate = 0.04 M, shaking time = 5.0 min., pH = 2 and 3,
strippant = 6.0 M NH4OH (2×10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 98
Fig. 8 log-log plot of distribution ratio Log D[Pd(II)] versus Log C[salicylate] at fixed
4-heptylaminopyridine concentration (0.05 M)
Conditions:
Pd(II) = 200 µg, pH = 3 and 4, shaking time = 5.0 min., 4-HAP = 0.05 M in xylene (10 mL),
strippant = 6.0 M NH4OH (2×10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 99
References:
[1] D. Jollie, Platinum 2008, Johnson Matthey, (2008) 1.
[2] P. Yong, N. A. Rowson, J. P. G. Farr, L. R. Harris, L. E. Macaskie, Environ.
Technol., 24 (2003) 289.
[3] C. B. Ojeda, F. S. Rojas, J. M. C. Pavon, Microchim. Acta, 158 (2007) 103.
[4] International Programme on Chemical Safety, Geneva, 226 (2002) 1.
[5] C. E. Garrett, K. Prasad, Adv. Synth. Catal., 346 (2004) 889.
[6] H. Serencam, V. N. Bulut, M. Tufekci, A. Gundogdu, C. Duran, S. Hamza, M.
Soylak, Int. J. Environ. Anal. Chem., 93 (2013) 1484.
[7] M. R. Awual, T. Yaita, S. A. El-Safty, H. Shiwaku, Y. Okamoto, S. Suzuki, Chem.
Eng. J., 222 (2013) 172.
[8] M. R. Awual, M. A. Khaleque, Y. Ratna, H. Znad, J. Ind. Eng. Chem., 21 (2014) 405.
[9] C. Locatelli, D. Melucci, G. Torsi, Anal. Bioanal. Chem., 382 (2005) 1567.
[10] W. X. Ren, T. Pradhan, Z. Yang, Q. Y. Cao, J. S. Kim, Sens. Actuators, B: Chem.,
171 (2012) 1277.
[11] L. A. Simpson, R. Hearn, T. Catterick, J. Anal. At. Spectrom., 19 (2004) 1244.
[12] Z. X. Li, Y. H. Feng, J. Anal. At. Spectrom., 21 (2006) 90.
[13] M. R. Awual, T. Yaita, Sens. Actuators, B: Chem., 183 (2013) 332.
[14] M. R. Awual, M. M. Hasan, J. Ind. Eng. Chem., 202 (2014) 395.
[15] A. N. Turanov, N. K. Evseeva, Russ. J. Appl. Chem., 77 (2004) 527.
[16] M. Domingueza, E. Antico, L. Beyer, A. Aguirre, S. G. Granda, V. Salvado,
Polyhedron, 21 (2002) 1429.
[17] A. A. Mhaske, P. M. Ddadke, Hydrometallurgy, 61 (2001) 143.
[18] P. P. Sun, M. S. Lee, Hydrometallurgy, 109 (2011) 181.
[19] K. Saitot, H. Freiser, Anal. Sci., 5 (1989) 583.
[20] A. T. Yordanov, J. T. Mague, D. M. Roundhill, Inorg. Chim. Acta, 240 (1995) 441.
[21] K. Shiomori, K. Fujikubo, Y. Kawano, Y. Hatate, Y. Kitamura, H. Yoshizawa, Sep.
Sci. Technol., 39 (2004) 1645.
[22] M. Wisniewski, J. Szymanowski, Anal. Sci., 14 (1998) 241.
[23] R. A. Khisamutdinov, Y. I. Murinov, O. V. Shitikova, Russ. J. Inorg. Chem., 52
(2007) 969.
[24] R. Ruhela, B. S. Tomar, A. K. Singh, R. C. Hubli, A. K. Suri, Dalton Trans., 42
(2013) 7085.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 100
[25] M. B. Gholivand, N. Nozari, Talanta, 52 (2000) 1055.
[26] K. Z. Hossain, T. Honjo, Fresenius J. Anal. Chem., 367 (2000) 141.
[27] K. Otho, E. Murakami, K. Shiratsuchi, K. Inoue, M. Iwasaki, Chem. Lett., (1996)
173.
[28] A. N. Turanov, V. K. Karandashev, A. N. Proshin, Solvent Extr. Ion Exch., 26 (2008)
360.
[29] P. Malik, A. P. Paiva, Solvent Extr. Ion Exch., 28 (2010) 49.
[30] M. Schwarzer, M. Schuster, R. V. Hentig, Fresenius J. Anal. Chem., 368 (2000) 240.
[31] D. V. Chavan, P. M. Dhadke, J. Sci. Ind. Res., 62 (2003) 834.
[32] N. M. Sundaramurthi, V. M. Shinde, Bull. Chem, Soc. Jpn., 63 (1990) 1508.
[33] R. A. Khisamutdinov, S. O. Bondareva, Y. Murinov, I. P. Baikova, Russ. J. Inorg.
Chem., 53(2008) 462.
[34] Y. Baba, A. Arima, S. Kanemaru, M. Iwakuma, T. Oshima, J. Chem. Engg. Jpn., 44
(2011) 686.
[35] K. Kaikake, Y. Baba, Anal. Sci., 17 (2001) 411.
[36] A. Cieszynska, M. Wisniewski, Sep. Purif. Technol., 73 (2010) 202.
[37] S. D. Kolev, Y. Sakai, R. W. Cattrall, R. Paimin, I. D. Potter, Anal. Chim. Acta, 413
(2000) 241.
[38] S. Mukherjee, S. Chowdhury, A. K.Paul, R. Banerjee, J. Lumin., 131 (2011) 2342.
[39] S. V. Bandekar, P. M. Dhadke , Sep. Purif. Technol., 13 (1998) 129.
[40] K. Ohto, J. Nagata, S. Honda, K. Yoshizuka, K. Inoue, Y. Baba, Solvent Extr. Ion
Exch., 15 (1997) 115.
[41] Y. baba, T. Eguchi, K. Enoue, Bull. Chem. Soc., 59 (1986) 1221.
[42] K. Kaikake, Y. Baba, Solvent. Extr. Ion Exch., 20 (2002) 491.
[43] N. Alizadeh, S. Salimi, A. Jabbari, Anal. Sci., 18 (2002) 307.
[44] M. A. Chaudry, N. U. Islam, N. U. Rahman, J. Radioanal. Nucl. Chemi., 218 (1997)
53.
[45] S. Katsuta, Y. Yoshimoto, M. Okai, Y. I. Takeda, K. Bessho, Ind. Eng. Chem. Res.,
50 (2011) 12735.
[46] T. Fujii, H. Yamana, M. Watanabe, H. Moriyama, J. Radioanal. Nucl. Chem,. 247
(2001) 435.
[47] V. V. Yakshin, O. M. Vilkova, I. G. Tananaev, B. F. Myasoedov, Russ. J. Gen.
Chem., 81 (2011) 1966.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 101
[48] V. G. Torgov, T. V. Us, T. M. Korda, G. A. Kostin, V. I. Kalchenko, Russ. J. Inorg.
Chem., 57 (2012) 1621.
[49] H. Narita, M. Tanaka, K. Morisaku, T. Abe, Chem, Lett., 33 (2004) 1144.
[50] M. Draye, A. F.Reguillon, G. L Buzit, J. Foos, M. Lemaire, A. Guy, J. Radioanal.
Nucl. Chem., 220 (1997) 105.
[51] M. Rovira, L. Hurtado, J. L. Cortina, J. Arnaldos, A. M. Sastre, Solvent Extr. Ion
Exch., 16 (1998) 545.
[52] I. A. Kovalev, L. V. Bogacheva, G. I. Tsysin, A. A. Formanovsky, Y. A. Zolotov,
Talanta, 52 (2000) 39.
[53] L. F. Dias, J. Nozaki, Anal. Lett., 31 (1998) 2489.
[54] D. A. Chowdhury, S. Kumata, Bull. Chem. Soc. Jpn., 70 (1997) 601.
[55] O. N. Kononova, N. G. Goryaeva, N. B. Dostovalova, S. V. Kachin, A. G.
Kholmogorov, Solid Fuel Chem., 41 ( 2007) 252.
[56] M. Wisniewski, A. Jakubiak, J. Szymanowski, J. Radioanal. Nucl. Chem., 228 (1998)
109.
[57] C. Fontas, M. Hidalgo, V. Salvado, Solvent. Extr. Ion Exch., 27 (2009) 83.
[58] J. Fu, S. Nakamura. K. Akiba, Sep. Sci. Technol., 32 (1997) 1433.
[59] N. T. Hung, M. Watanabe, T. Kimura, Solvent Extr. Ion Exch., 25 (2007) 407.
[60] J. M. Ouyang, Solvent Extr. Ion Exch., 17 (1999) 1255.
[61] B. Gupta, I. Singh, Hydrometallurgy, 134–135 (2013) 11.
[62] J. Y. Lee, B. Raju, B. N. Kumar, J. R. Kumar, H. K. Park, B. R. Reddy, Sep. Purif.
Technol. 73 (2010) 213.
[63] J. Traeger, J. König, A. Städtke, H. J. Holdt, Hydrometallurgy, 127-128 (2012) 30.
[64] J. P. Shukla, R. K. Singh, S. R. Sawant, N. Varadarajan, Anal. Chim. Acta, 276
(1993) 181.
[65] K. Inoue, K. Yoshizuka, Y. Baba, F. Wada, T. Matsuda, Hydrometallurgy, 25 (1990)
271.
[66] E. M. Donaldson, E. Mark, Talanta, 29 (1982) 663.
[67] B. K. Tait, D. P. Shillington, S. Afr J. Chem., 45 (1992) 17.
[68] R. A. Khisamutdinov, G. R. Anpilogova, L. G. Golubyatnikova, I. P. Baikova, Y. I.
Murinov, Russ. J. Inorg. Chem., 57 (2012) 120.
[69] M. Rovira, J. L. Cortina, A. M. Sastre, Solvent Extr. Ion Exch., 17 (1999) 333.
[70] B. Peng, X. Guo, X. Mao, J. Gao, Cent. Eur. J. Chem., CEJC, 5 (2007) 912.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 102
[71] T. Ogata, K. Takeshita, G. A. Fugate, A. Mori, Sep. Sci. Technol., 43 (2008) 2630.
[72] T. Z. Sadyrbaeva, Sep. Sci. Technol., 41(2006) 3213.
[73] N. Shokoufi, F. Shemirani, M. Shokoufi, Spectrochim. Acta A, 74 (2009) 761.
[74] Z. Tu, S. Lu, X. Chang, Z. Li, Z. Hu, L. Zhang, H. Tian, Microchim. Acta, 173 (2011)
231.
[75] O. M. Singh, S. J. Singh, S. N. Kim, S. G. Lee, Bull. Korean Chem. Soc., 28 (2007)
115.
[76] Z. Marczenko, Ellis Horwood Limited, Chichester, 1976, pp. 309, 373, 231, 430, 459,
326, 303, 153, 415, 493, 524, 243.
[77] T. G. Appleton, A. J. Bailey, D. R. Bedgood Jr., J. R. Hall, Inorg. Chem., 33 (1994)
217.
[78] E. B. Sandell, third ed., Interscience, New York, NY, 1965, pp. 702, 781, 505.
[79] H. A. Flaschka, A. J. Bernard, Marcel Dekkar, Inc., New York, NY, 1972, pp. 79,
164, 134.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 103
Chapter IV
Development of a solvent extraction
system with 4-heptylaminopyridine for
the selective separation of platinum(IV)
from catalysts, anticancer injections and
water samples
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 104
4.1 Introduction
Platinum is an element in the platinum group of metals (PGMs), which are
available in nature as an arsenite compound or in a sulfide associated with copper,
nickel, iron, etc. Platinum is employed in various industries, in electronics and
electrical devices, in catalysts, jewelry and dental materials, for the production of fuel
cells, for platings and coatings, and in glass making. As a catalyst, it is widely used in
the automobile, chemical and petrochemical industries. Secondary/waste materials
containing platinum are generated and discarded during production and at the end of
service life. To recover valuables from primary and secondary resources,
pyro/hydrometallurgical processes consisting of roasting and leaching are usually
employed to dissolve the metals into an aqueous phase using suitable lixiviants [1].
The consumption of platinum and palladium by the autocatalyst sector is rising by 5%
each year. As a consequence spent automobile catalysts have emerged as a major
secondary source of platinum and palladium [2].
Platinum demand in 2003/2004 was higher than the world supply [3]. Although
the demand decreased 2.3% in 2008, platinum supply decreased 4.2% [4].
Platinum metal is also very scarce element in earth’s crust. The worldwide reserves of
platinum metal are concentrated in only Siberia and South Africa. Although the
amount of this metal in a commercial catalyst is approximately1 wt.%, it corresponds
to the main cost of this product [5, 6]. Therefore, recycling of spent catalysts is an
attractive way to lower the catalyst cost [7]. Economically, the platinum group metals
are important as investment commodities and currency. Under ISO 4217 the
palladium, silver, platinum and gold are internationally recognized as forms of
currency [8]. Cisplatin, cis-diammine-dichloro-platinum(II), is an inorganic
coordination compound commonly used in the treatment of different solid tumors.
However, it is also highly toxic and probably carcinogenic to humans [9]. The
presence of cisplatin in water and wastewater has been reported. Excretion via faeces
and urine of patients under medical treatment, the disposal of unused pharmaceuticals
[10-12] in effluent from hospitals [13-16] and the wastewater generated during the
pharmaceutical manufacturing process [17] represent the major contamination sources
for this cytostatic drug.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 105
4.2 Review of literature for solvent extractive separation of Pt(IV)
Solvent extraction of Pt(IV) from nitrate, chloride and sulfate solution has been
examined by using bis(2,4,4-trimethylpentyl) monothiophosphinic acid (Cyanex 302)
[18] in kerosene and Cyanex 923 [19] in toluene from chloride media. From chloride
leach liquors of spent automobile catalyst [20] and platinum-191 radiotracer [21] the
platinum was extracted and separated with rubeanic acid (ethanedi-thioamide) in
tributyl phosphate was examined. N,N-diethyl-N'-benzoylthiourea (DEBT) [22] was
used to extract the Pt(IV) by optimizing the mole ratio of metal to chelating agent,
concentration of acid, extraction time and temperature. The solvent extraction of
Pt(IV) with bis(n-octylsulphinyl) ethane BOSE [23] was studied. Results showed that
platinum(IV) were not extracted from hydrochloric acid solution with BOSE into
butyl- acetate or chloroform but it could be extracted from 2 to 6 M HCl in the
presence of potassium iodide. p-(I,1,3,3-Tetramethylbutyl)phenyl hydrogen [N,N-
di(2- ethylhexyl)aminomethyl-phosphonate [24] was used as a novel extractant to
study the extraction behavior of platinum(IV) from aqueous chloride media. Solvent
extraction of platinum from chloride media has been carried out by using N,N'-
dimethyl-N,N'-diphenyltetradecylmalonamide [25]. Platinum can be quantitatively
extracted in the presence of tin and can also be successfully stripped by using an
aqueous mixture of 4 M HCl + 0.05 M NaClO3. The effect of tin(II) chloride on the
extraction behavior of tetrachloroplatinate(II) [26] in 1.0 to l.5 M hydrochloric acid
into dichloromethane with triphenylphosphine (TPP) were investigated. Tin(II)
chloride increases the rate and efficiency of platinum extraction. Extraction of Pt, Pd,
Ir by macrocyclic polyethers, cis-sin-cis dicyclohexyl-18-crown-6 (DCH18C6 "A")
and dibenzo-18-crown-6 (DB18C6) [27, 28] in organic solvents (1,2-dichloroethane
and chloroform) from 3 to 10 M HCl aqueous solution was studied. Isobutyl methyl
ketone (MIBK) was used for extraction of Pt(IV) from HCl media with complexing
ligand SCN- [29]. Solvent extraction of Pt(II) with 1,3-dimethyl-2-thiourea (DMTU)
[30] from a chloride medium was examined. 1,2-dichloroethane as an extraction
solvent and bromocresol green ion as a counter anion were used. Within 15 min Pt(II)
was extracted into 1,2-dichloroethane quantitatively. The obstructions of Zn(II),
Mn(II), Ag(I), Cu(II), Cd(II) and Pd(II) was eliminated by adding relevant trapping
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 106
agents. The pH selective extraction of platinum by using N’N’- dihexyl and phenyl
and N’-hexyl and phenyl derivatives of N-benzoyl thiourea [31] was carried out. The
extraction of platinum(II) and palladium(II) with bis(2,4,4-trimethylpently)
phosphinodithioic acid [32] from chloride solution has been investigated. The effect of
tetraheptylammonium thiocyanate, thiourea and tetraheptylammonium chloride on the
extraction of Pt(II) is studied. Pt(II) was quantitatively extracted by this method. N,N'-
dimethyl-N,N'-diphenyltetradecylmalonamide (DMDPHTDMA) [33] dissolved in
1,2-dichloroethane has been studied as a extraction reagent to mainly perform the
separation of Rh from other PGMs and from some commonly associated elements
contained in concentrated hydrochloric acid media. The developed extraction method
was applied to an automobile catalytic converter leaching solution. n-Butyl
isooctylamide (BiOA) [34] in octane has been studied as a solvent extraction reagent
for extraction of Pt(IV).
N,N'-dipentylethylendiamine-N'-thiocarbaldehyde (L) [35] was used as a
solvent extraction reagent for extraction of Pt(IV) from hydrochloric acid solution at
25°C. Chloroform and toluene were used as solvents. The solvent extraction and
separation of Pt(IV) from HCl solutions were examined by using di-Bu sulfoxide [36]
diluted in kerosene. Separation of Pt(IV) was studied from several common ions like
Ni(II), Fe(II) and Cu(II). The solvent extraction of thiocyanate complexes of PGMs
ions by MIBK [37, 38] in hydrochloric acid medium was studied. Solvent extraction
of Pt(IV) from hydrochloric acid solution was studied by using 2-hydroxy-4-sec-
octanoyl diphenyl ketoxime [39] diluted in kerosene as an extractant. P-50 oxime [40]
diluted in Escaid 100 has been used to extract platinum(II) prepared in situ, from
aqueous chloride solutions. The Pt(II) was subjected to slow atmospheric oxidation
which resulted in low distribution ratio values. The equilibrium distribution of Pt(IV)
between hydrochloric acid and trioctylphosphine oxide [41] in toluene at 303 K was
investigated. The extraction equilibrium constant was found to be Ke = 3.6 × 103. The
solvent extraction of Pt(II) with 12-14,16-membered cyclic tetra thioethers [42] from
chloride medium were investigated. 1,2-dichloroethane as an extraction solvent and
bromocresol green ion as a counter anion were used. However, method required 5 h
for platinum(II) extraction in presence of thiourea. Solvent extraction of Pt(II) by
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 107
using N,N'-dipentylethylenediamine-N'-thiocarbaldehyde [43] from 0.1 M
hydrochloric acid solution into toluene and chloroform diluents was examined at 25°C
and a shaking time of 5 min. Extraction of platinum(IV) from HCl media with
solution of two bis(aminophosphonates), such as N,N'-bis[[(dioctyloxyphosphoryl)
methyl]butylamine] and N,N-bis(dipentoxyphosphorylmethyl)-octylamine [44] in
xylene and chloroform was studied. The extraction of Pt(IV) from aqueous HCl
solution with solution of bis(2-ethylhexyl) N-butyl-N-octylaminomethylphosphonate
[45] in xylene and chloroform was investigated.
The extraction of halo complexes of platinum(IV) by dipyrazolonylmethanes
[46] was investigated and developed method was used for the chemical atomic
emission determination. The solvent extraction method was developed for
platinum(IV) by using propiconazole (1) [47] from 3 M hydrochloric acid solutions.
N,N-di(2-ethylhexyl) aminomethylquinoline (DEQ) [48] has been used to develop
selective solvent extraction method for platinum(IV). 1-[2-(2,4-Dichlorophenyl)-4-
propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole [49] was examined for the
extraction of Pt(IV). A novel sulfur-containing extraction reagent, 3,3-diethylthietane
(DETE) [50] was studied for extraction of Pt(IV) from hydrochloric acid solution at
30°C. Extraction of platinum(IV) with dihexyl sulfide (DHS) [51-53] from chloride
medium and the degradation of DHS to dihexyl sulfoxide (DHSO) were examined in
this study. The kinetics of the extraction of Pt(IV) from HCl media with petroleum
sulfoxide (PSO) [54] diluted in kerosene has been investigated. The solvent extraction
reagent nonylthiourea (NTH) [55, 56] dissolved in chloroform was used for extraction
of Pt(IV) from chloride medium at 4.0 M ionic strength has been investigated. It is
found that chloride concentration has a negative effect on the extraction while proton
concentration has no effect on extraction. The Pt ion in deactivated catalyst for the
hydro chlorination reaction of ethyne was extracted by acidic thiourea [57] solution.
The intention of the present work is to reveal some new information about the
use of a 4-heptylaminopyridine as a novel extractant for the extraction and separation
of platinum(IV). The effect of various parameters, like equilibration time, diluents,
concentration of extractant, organic/aqueous (O/A) phase ratio, acidity, loading
capacity, stripping and diversity of ions, has been investigated. The developed method
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 108
has been extended for the recovery of platinum from catalysts, Pt–Rh thermocouple
wire, anticancer injections (cytoplatin) and water samples.
The review of literature for comparison of solvent extractive separation of
Pt(IV) is given in Table 1.
Table 1 Summary of methods of solvent extraction of platinum(IV)
System Aqueous
phase
Organic
phase
Special features Ref.
No.
Bis(2,4,4-
trimethylpentyl)
monothiophosphinic
acid (Cyanex 302)
Sulfate,
chloride
and
nitrate
Kerosene
Extraction increases
with increase in
concentration in the
ascending order
sulfate > chloride >
nitrate.
18
Cyanex 923 HCl
Toluene
Strippant 5 M HNO3.
Method applicable
for recovery of metal
ions from synthetic
mixtures.
19
Chloride leach liquors HCl
Kerosene
Recovery of
platinum(IV) 99.9 %
20
Rubeanic acid
(ethanedi- thioamide)
3 M
HCl
TBP
Back extraction with
2 M ammonia
solution.
The best overall
recovery was 75-81
%, it could be
increased to 90 % by
performing the
experiment twice.
21
N,N-diethyl-N’-
benzoyl- thiourea
(DEBT)
2 M HCl
Toluene
DEBT shows
extraction in the order
of Pd(II)>Pt(II)>
Ru(III)>
Rh(III)>Ir(III)
at ligand/metal ratio >
4.
22
Bis(n-octyl-sulphinyl)
ethane (BOSE)
2-6 M
HCl
Chloroform
or butyl
acetate
Extraction in
presence of
potassium iodide.
Platinum can’t be
separated from
palladium.
23
P-(1,1,3,3-tetramethyl
butyl)phenyl H N,N-
di(2- ethylhexyl)
amino-methyl
0.01- 6 M
HCl
Toluene
High lipophilicity
leads to higher
extraction than that
from N,N-di(2-ethyl
24
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 109
phosphonate (HR)
hexyl) amino
methylphosphoric
acid.
Extraction for
precious metals.
Iron(III) interference.
N,N'-dimethyl-N,N'-
diphenyltetradecylmal
on- amide
HCl
-
Effective extraction
in presence of tin(II)
chloride.
Back stripped by
mixture of 0.05 M
NaClO3 + 4 M HCl
25
Triphenylphosphine HCl,
1-1.5 M
1,2-
Dichloro
Ethane
The rate and
efficiency greatly
increased in presence
of tin(II) chloride.
Percentage extraction
depends on time
allowed for extraction
ratio of Pt: Sn(II):TPP
and to less extent on
concentration of
hydrochloric acid.
26
Dibenzo-18-crown-6
(DB18C6) and cis-sin-
cis dicyclohexyl-18-
crown-6 (DCH18C6)
HCl
Dichloroetha
-ne &
Chloroform
Extraction process
applicable for Pd(II),
Ir(III), Rh(III)
28,
27
Methyl iso butyl
ketone
2- 3 M
HCl
MIBK
Extraction in
presence of 5 %
potassium
thiocyanate.
95 % extraction was
achieved.
29
1,3-Dimethyl-2-
thiourea (DMTU)
HCl
1,2-
Dichloroeth
-ane
Phase contact time 15
min.
Interference
eliminated by adding
suitable masking
agents.
30
N’N’- dihexyl and
phenyl and N’-hexyl
and phenyl derivatives
of N-benzoyl- thiourea
HCl
pH 3
Decane,
chloroform,
solvesso150
& toluene
Temperature and pH
dependent extraction.
Heat at 95o C.
Ni, Fe, Cu interfere.
31
Bis-(2,4,4-trimethyl
pentyl)
phosphinodithioic acid
0.1M
HCl
Heptane
Thiourea was added
to increase therate of
extraction.
Shaking time 1 h.
32
N,N'-dimethyl-N,N'- HCl 1,2- Method was 33
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 110
diphenyltetradecyl-
malonamide
(DMDPHTDMA)
Dichloroe-
thane
applicable for
separation of Pt(IV)
from other PGMs.
n-Butyl isooctylamide
(BiOA)
HCl
Octane
Platinum(IV)
extraction
99.5 %.
Water was effective
stripping agent.
34
N,N’-
dipentylethylendiamin
e-N’-
thiocarbaldehyde
HCl
Chloroform
or toluene
Method studied at
25oC
Determination by
NMR and IR
35
Di-butyl sulfoxide HCl
Kerosene
Extraction &
separation was
carried out from
several common
impurities like Cu(II),
Ni(II) and Fe(II).
36
Methyl iso butyl
ketone HCl MIBK
Extraction of
thiocyanate
complexes of PGMs.
37,
38
2-Hydroxy-4-sec-
octanoyl
diphenyl-ketoxime
HCl
Kerosene
Applicable for Pd(II)
and Au(III).
39
P-50 oxime HCl
Escaid 100
Co-extraction of
Pd(II).
40
Trioctylphosphine
oxide
HCl
Toluene
Equilibrium constant
Ke = 3.6 × 103.
41
12-14,16-Membered
cyclic tetra thioethers
HCl
1,2-
Dichloroeth
-ane
Method required 5 h
for platinum(II)
extraction.
Bromocresol green
ion act as a counter
anion.
42
N,N'-
dipentylethylenediami
ne-N'-
thiocarbaldehyde
0.1 M
HCl
Toluene &
Chloroform
Method was studied
at 25°C.
A phase contact time
is 5 min.
43
N,N-
bis(dipentoxyphosphor
ylme- thyl)octylamine
and N,N'-
HCl
Xylene &
chloroform
Platinum(IV) and
Palladium(II) can’t
separated from one
another.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 111
bis[[(dioctyloxyphosp
horyl)methyl]butylami
ne]
Platinum(IV)
separated from
Fe(III), Cu(II), Co(II)
and Ni(II).
44
bis(2-ethylhexyl) N-
butyl-N-
octylaminomethyl
phosphonate
HCl
Xylene &
chloroform
High selectivity of
separation from the
contaminants Fe(III),
Ni(II), Co(II) and
Cu(II) ions.
The most efficient at
low acidities.
45
Dipyrazolonylheptane
0.25 M
H2SO4
0.1 M
NH4Cl
Chloroform
Determined by
emission
spectroscopy.
Hg interfered.
46
Propiconazole (1)
HCl
Toluene
Platinum(IV)
extraction depending
upon concentration of
hydrochloric acid.
47
N,N-di(2-ethyl hexyl)
aminomethylquinoline
(DEQ)
HCl
Toluene
Platinum(IV)
extraction depending
upon concentration of
hydrochloric acid.
48
1-[2-(2,4-
dichlorophenyl)-4-
propyl-1,3-dioxolan-2-
ylmethyl]-1H-1,2,4-
triazole
HCl
Toluene
Extraction follows the
anion-exchange
mechanism.
49
3,3-diethylthiethane
(DETE)
HCl
Toluene
Extraction was
achieved at 30oC.
Platinum(IV) was
extracted as a
solvated complex of
type PtCl4.4DETE.
50
Dihexyl sulphide
(DHS)
Chloride - Extraction of small
amounts of
platinum(IV) causes
oxidation of DHS to
DHSO as well as the
reduction of
platinum(IV) to
platinum (II).
51-
53
Insoluble substance
was decreased by the
addition of modifier
like alcohol.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 112
Extraction of
platinum(IV)
increased by increase
of phase contact time
and decrease of
palladium(II)
concentration.
Petroleum sulfoxide
(PSO)
HCl
Kerosene
Effect of H+ and Cl-
ions, temperature,
stripping is studied.
54
Nonylthiourea (NTH)
HCl Chloroform
Heating is required. 55,
56
Thiourea HCl
Ethyne
98 % extraction was
achieved.
57
4.3 Experimental
4.3.1 Apparatus
UV/VIS Spectrophotometer model-Optizen α (mecasys Co., Ltd/made in
Korea) with 1cm quartz cell has used for absorbance measurements and pH
measurements are carried out with an Elico Digital pH meter Model LI-120 with a
combined glass electrode.
4.3.2 Reagents
4.3.2.1 Standard platinum(IV) solution
A standard solution of platinum(IV) was prepared by dissolving 1 g (1 X 10-3
kg) of hydrogen hexachloroplatinate(IV) hydrate, H2PtCl6 .H2O (Johnson and
Matthey, UK), in 1 M hydrochloric acid and was standardized gravimetrically [58]. A
working solution (200 µg mL-1) was made using the appropriate dilution.
4.3.2.2 4-Heptylaminopyridine solution (0.06 M)
To a stirred solution of 4-aminopyridine (0.05 mol) in dry THF (40 mL),
sodium amide was added at 0 oC and stirring was continued for 30 min. The
temperature of the reaction mixture increased to room temperature and 1-
bromoheptane was added slowly. The reaction mixture was stirred at ambient
temperature for 1 h. The reaction mixture was poured into water containing NH4Cl
and extracted with chloroform (150 mL). The chloroform extract was dried (Na2SO4)
and evaporated using a rotary evaporator to yield a residue which was crystallized to
afford the corresponding 4-heptylaminopyridine in 75–85% overall yield [59] and it's
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 113
solutions were prepared in xylene. Other standard solutions of diverse ions were
prepared by dissolving weighed quantities of their salts in water or dilute HCl [60].
Different synthetic mixtures containing platinum(IV) were prepared by combining
with commonly associated metal ions in definite compositions [61]. All of the other
chemicals and solvents were of AR grade and double distilled water was used
throughout the experiments.
4.3.2.3 Stannous chloride solution (25% w/v)
Stannous chloride (25 g) was dissolved in 25 mL of conc. hydrochloric acid
and diluted with water to 100 mL.
4.3.3 Extraction procedure
An aliquot of 200 µg of platinum(IV) solution was mixed with 0.0308 g of
ascorbic acid to make a concentration of 0.007 M in a total volume of 25 mL of the
solution. The pH of the aqueous solution was adjusted to 1.5 using dil. sodium
hydroxide and hydrochloric acid solution. The solution was then transferred into a 125
mL separating funnel and shaken with 10 mL of 0.06 M 4-heptylaminopyridine in
xylene for 2 min. After separating the two phases, the aqueous phase was discarded
and the organic phase was stripped with two 10 mL portions of water solution. After
being stripped with water, platinum(IV) was put into the aqueous phase quantitatively.
The stripped aqueous phase was evaporated to moist dryness and extracted into dil.
hydrochloric acid.
4.3.4 Estimation procedure for platinum(IV)
The resulting aqueous phase was mixed with 5 mL of concentrated
hydrochloric acid and 10 mL of 25% stannous chloride. The solution was diluted to
the mark with water in a 50 mL volumetric flask. The absorbance of the resultant
solution was measured at 403 nm [61]. The concentration of platinum(IV) was
calculated in terms of percentage extraction (%E).
4.4 Results and discussion
4.4.1Extraction of platinum(IV) as a function of pH
Extraction of platinum(IV) was performed between pH 0.10 and 6.0 in a fixed
concentration of 0.007 M of ascorbic acid using a 0.06 M solution of 4-
heptylaminopyridine in xylene. The extraction was found to be quantitative within a
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 114
pH range of 0.5 to 2.0 (Fig. 1). With an increase in the pH to above 2.0 the extraction
kept decreasing. Hence, the extraction of platinum(IV) was carried out at pH 1.5 for
all of the extraction experiments (Table 2). The decrease in extraction with the
increase in pH value was due to the hydrolysis of the ion–pair complex.
4.4.2 Extraction as a function of weak organic acid concentration
The extraction behavior of platinum(IV) from ascorbic acid, sodium salicylate,
sodium malonate and sodium succinate at pH 1.5 using 0.06 M 4-heptylaminopyridine
in xylene was studied (Table 3). The extraction initiated in 0.001 M ascorbic acid and
became quantitative in the concentration range of 0.005 to 0.01 M. With the
increasing concentration of ascorbic acid, there was a decrease in the extraction of
platinum(IV). This may be due to formation of stable 4-heptylaminopyridine–
ascorbate species. Therefore, 0.007 M ascorbic acid was used throughout this work.
There was incomplete extraction of platinum(IV) from malonate, salicylate and
succinate media (Fig. 2).
4.4.3 Effect of extractant concentration
The effect of extractant concentration in the range of 0.01 to 0.1 M of 4-
heptylaminopyridine in xylene was studied for the extraction of 200 µg of
platinum(IV) from 0.007 M ascorbic acid (Table 4). It was found that 10 mL of 0.055
M extractant was sufficient for the quantitative extraction of the 200 µg of
platinum(IV) from 0.007 M ascorbic acid. However, in the recommended procedure
10 mL of 0.06 M 4-heptylaminopyridine in xylene was used to ensure the complete
extraction of the metal ion. There was no adverse effects of using an excess of 4-
heptylaminopyridine (Fig. 3).
4.4.4 Effect of diluents
The extraction of the 200 µg of platinum(IV) from 0.007 M ascorbic acid
media using 0.06 M 4-heptylaminopyridine in various aliphatic and aromatic diluents,
like n-hexane, benzonitrile, kerosene, cyclohexane, benzyl alcohol, toluene, xylene,
dichloroethane, chloroform, and carbon tetrachloride was tested (Table 5). The
extraction of platinum(IV) was quantified with inert diluents, such as xylene and
toluene, because the ion–pair complex has a high distribution ratio value in these
solvents. Whereas carbon tetrachloride (47%), kerosene (52.4%) and chloroform
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 115
(89.7%) were found to be poor solvents (Fig. 4), while there was no extraction in n-
hexane, benzonitrile, benzyl alcohol, dichloroethane and cyclohexane. No correlation
between dielectric constant and percentage extraction was observed. In the present
study, xylene was used as the diluent as it is cheap, there is no emulsion formation and
the phase separation took place rapidly.
4.4.5 Effect of equilibration time
The extraction behavior of platinum(IV) from ascorbic acid media using 0.06
M 4- heptylaminopyridine in xylene has been measured at different equilibration
times of 6 s to 20 min (Table 6). It has been observed that, under the optimized
experimental conditions, a minimum 25 second time interval is required for attaining
equilibrium in order to extract platinum(IV) quantitatively. In the recommended
procedure, a 2 min equilibration time was recommended for ensuring the complete
extraction of platinum(IV). However, a prolonged shaking period was found to have
an adverse effect on the extraction and should be avoided (Fig. 5). This may be due to
the dissociation of the ion–pair complex.
4.4.6 Stripping of platinum(IV) from the loaded organic phase
Back stripping is the reverse process of extraction. Therefore, stripping of
platinum(IV) from the loaded organic phase was carried out using NH3, ammonia
buffer (pH 10), H2O, HCl, HNO3, H2SO4, NaCl, KOH and NaOH (Table 7). The
stripping of platinum(IV) was quantified with water. The stripping was found to be
incomplete using NaCl (12.7%), NH3 (20.6%), ammonia buffer (pH 10) (27%), NaOH
(35.8%), KOH (42.3%), HCl (52.3%) and HNO3 (55.9%). In the recommended
procedure, two 10 mL portions of water were used for the complete stripping of the
loaded organic phase.
4.4.7 Effect of aqueous to organic volume ratio
The results of using different volume ratios of aqueous to organic phases have
been studied. The results indicate that the preferred aqueous/organic (A/O) phase ratio
in this study was 2.5 : 1. This is evident from the sharp increase in the separation
efficiency, as well as the distribution ratio of platinum(IV), when the phase ratio
(A/O) changed from 10 : 1 to 5 : 1. This may simply be due to the unavailability of
reagent for metal extraction and so a crowding effect occurs at a low phase ratio.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 116
However, in the recommended procedure, the phase ratio was maintained as 2.5 : 1
(Table 8).
4.4.8 Metal loading capacity of extractant
The loading capacity of 0.06 M 4-heptylaminopyridine was determined by
using 10 mL of the organic phase for 2 min repeatedly with the 25 mL of aqueous
phase containing varied concentrations of platinum(IV) (Table 9). The maximum
loading capacity of 10 mL of a 0.06 M solution of 4-heptylaminopyridine in xylene
was found to be 2000 µg of platinum(IV) (Fig. 6).
4.4.9 Mechanism for the extraction of platinum(IV)
Attempts were made to ascertain the nature of the extracted species using log
D–log C plots. The graphs of log D[Pt(IV)] against log C[4-HAP] at a fixed ascorbic acid
concentration (0.007 M) were found to be linear, having slopes of 0.78 and 0.77 at pH
2 and 2.25, respectively (Fig. 7). Also, plots of log D[Pt(IV)] against log C[ascorbic acid] at
fixed 4-heptylaminopyridine concentration (0.06 M) were linear and the slope values
were found to be 2.78 and 2.87 at pH 2 and 2.25, respectively (Fig. 8). The probable
composition of the extracted species was calculated to be 1 : 3 : 1 (metal : acid :
extractant). In the extraction of platinum(IV) with ascorbate medium, the first
platinum(IV) was reduced to platinum(II) [63] then it was converted into a
platinum(II) ascorbate species as an anionic complex and interacted with RR’NH2+.
Hence, the probable extracted species in xylene are [RR’NH2+.Pt(C6H7O6)3
-]org
species.
The probable mechanism of extraction is:
RR'NH(org) + H+ascorbate(aq)- [RR'NH2
+ascorbate-](org) (1)
H2PtIVCl6Ascorbic acid
Reducing agentPtIICl4
2- + 2 HCl (2)
Pt2+ + 3 ascorbate- [Pt(ascorbate)3](aq)-
(3)
[Pt(ascorbate)3](aq)-
[RR'NH2+ascorbate-](org)
[RR'NH2+ Pt(ascorbate)3
-](org) + ascorbate(aq)-(4)+
Probable Stripping mechanism:
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 117
[RR'NH2+ Pt(ascorbate)3
-](org) + H2O RR'NH + H3O+ + Pt(ascorbate)3
- (5)
4.4.10 Effect of various foreign ions on percentage extraction
The effects of various diverse ions on the extraction of platinum(IV) using 4-
heptylaminopyridine in xylene were tested. The tolerance limit of individual diverse
ions was determined with an error of less than ± 2%. It was observed that the method
is free from interference from a large number of cations and anions (Table 10). The
only species that showed interference in the procedure were Pd(II), Rh(III), iodide,
thiocyanate, thiourea and thiosulphate. However, the interference due to co-extraction
of Pd(II) and Rh(III) was eliminated by masking with tartrate. However, thiocyanate,
thiosulphate and thiourea make very strong complexes with platinum(IV). This is due
to soft acid and soft base combination while iodide ions form strong anionic species
with platinum(IV).
4.5 Applications
4.5.1 Separation and determination of platinum(IV) from binary mixtures
The separation of Pt(IV) from some commonly associated metal ions like
Ru(III), Os(VIII), Ir(III), Rh(III), Au(III), Fe(III), Co(II), Ni(II), Hg(II), Cd(II), Zn(II),
Pd(II), Bi(III), Te(IV), and Ag(I) using 4-heptylaminopyridine was achieved by taking
advantage of the difference in the extraction conditions of the metals, such as the pH
of the aqueous phase, reagent concentration and use of masking agent (Table 11). All
of the added metal ions remained quantitatively in the aqueous phase from which they
were determined spectrophotometrically using standard methods [60, 61]. Rh(III) and
Pd(II) interfered with the procedure due to their co-extraction with Pt(IV). Rh(III) and
Pd(II) were separated from Pt(IV) by masking them with 10 mg of tartrate. The
masked metal ions from the aqueous phase were de-masked with perchloric acid and
determined spectrophotometrically using the standard method [61].
4.5.2 Separation of platinum(IV) from ternary synthetic mixtures
Platinum(IV) is one of the platinum group metals (PGMs), and therefore, it was
separated from Ru(III) and Ag(I); and Rh(III) and Pd(II). The Rh(III) and Pd(II) were
masked by tartrate as a masking agent. Other platinum group metals were not
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 118
extracted with the optimum extraction conditions of platinum(IV). Platinum(IV) was
also isolated from Os(VIII) and Te(IV); Ir(III) and Bi(III); Au(III) and Zn(II); Fe(III)
and Cd(II); Co(II) and Hg(II); Ni(II) and Ru(III); Hg(II) and Os(VIII); Cd(II) and
Ir(III); Zn(II) and Cd(II); Pd(II) and Fe(III); and Ag(I) and Bi(III). The results are
found to be quantitative (Table 12).
4.5.3 Determination of platinum(IV) in catalyst samples
A catalyst (0.1 g) was dissolved in 5 mL of aqua regia. The solution was
evaporated to moist dryness. Two 3 mL portions of hydrochloric acid were added and
evaporated until all of the nitric acid was removed. The residue was extracted in 1 M
hydrochloric acid. The solution was filtered and the filtrate was diluted to 100 mL. An
aliquot of this diluted solution was analyzed for its platinum(IV) content using the
proposed method. It was found that there is a good agreement with the certified value
(Table 13).
4.5.4 Analysis of anticancer injections (cytoplatin)
The method permits the separation and determination of platinum(IV) from
anticancer injections (cytoplatin). A known volume (10 mL) of cisplatin solution was
digested in perchloric acid/nitric acid (10 : 1) and evaporated to dryness until the
organic matter was removed. The obtained residue was dissolved in concentrated
hydrochloric acid and diluted with water to 10 mL in a standard volumetric flask. An
aliquot of the sample solution was taken and the amount of platinum(IV) was
determined using the recommended procedure (Table 14).
4.5.5 Analysis of Pt–Rh thermocouple wires for platinum content
The proposed procedure was used for the estimation of the amount of
platinum(IV) in a Pt–Rh thermocouple wire (Table 14). A known weight (0.100 g) of
thermocouple wire was preliminarily fused with zinc powder and the melt was cooled
and dissolved in hydrochloric acid. The black powder remaining was treated with 5
mL of aqua regia. After the reaction was over, the whole solution was heated with two
5 mL portions of concentrated hydrochloric acid until the complete removal of the
oxides of nitrogen and diluted with water to 10 mL in a standard volumetric flask. An
aliquot of the sample solution was taken and the amount of platinum(IV) was
determined using the recommended procedure.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 119
4.5.6 Determination of platinum(IV) in water samples
In order to investigate the accuracy and applicability of the method, it was used
for the determination of platinum(IV) in water samples collected from different
sources. The water samples that were collected were filtered through Whatman filter
paper no. 40 to remove suspended matter, impurities etc., and then boiled for 5 min to
remove chlorine and dissolved gases. Then, the water samples were spiked with 200
µg of platinum(IV) and the developed method was applied for the determination of
platinum(IV) in the spiked water samples. The results were in good agreement with
the amount of platinum(IV) added (Table 15).
4.6 Conclusions
4-Heptylaminopyridine has been proven to be a sensitive, selective extractant
for the separation of platinum(IV) from commonly associated metal ions. The
developed method is simple, reproducible and requires less time for the separation of
platinum(IV). The important features of the proposed methods are,
(i) A low concentration of extractant is required for the quantitative extraction of
platinum(IV).
(ii) 4-Heptylaminopyridine forms an ion–pair complex with platinum(IV) in ascorbic
acid medium.
(iii) Extraction of platinum(IV) has been carried out without the addition of any
synergent or modifier at room temperature.
(iv) Ecofriendly strippant (water) is used for the stripping of platinum(IV); its use in
this method follows one of the principles of green chemistry.
(v) The developed method is free from interference from a large number of diverse
ions which are commonly associated with platinum(IV). The selectivity was also
enhanced using suitable masking agents.
(vi) The developed method is reproducible, simple and can be used for the extraction
of platinum(IV) from binary and ternary metal ion mixtures.
(vii) The developed method has been successfully used for the extraction of
platinum(IV) from real samples such as catalysts, Pt–Rh thermocouple wires,
anticancer injections and water samples.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 120
Table 2 Extraction of platinum(IV) as a function of pH
Platinum(IV) = 200 μg Aq.: Org. = 2.5: 1
Ascorbic acid = 0.007 M Org. = 0.06 M 4-HAP in xylene (10 mL)
Strippant = Water (2×10 mL)
pH Percentage extraction, (% E) Distribution ratio, (D)
0.10 35.0 1.34
0.25 65.0 4.64
0.50 100 ∞
0.75 100 ∞
1.0 100 ∞
1.25 100 ∞
1.50* 100 ∞
1.75 100 ∞
2.0 100 ∞
2.25 60.4 3.81
2.50 25.2 0.84
3.0 16.1 0.47
4.0 10.2 0.28
5.0 4.98 0.13
6.0 2.05 0.052
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 121
Table 3 Extraction as a function of weak organic acid concentration
Platinum(IV) = 200 μg Aq.: Org. = 2.5: 1
Org. = 0.06 M 4-HAP in xylene (10 mL) pH = 1.5
Strippant = Water (2×10 mL)
Acid conc. (M)
Ascorbic acid Sodium
salicylate
Sodium
malonate
Sodium
succinate
% E D % E D % E D % E D
0.001 40.4 1.69 34.3 1.30 32.2 1.18 29.3 1.03
0.002 55.1 3.06 43.4 1.91 39.2 1.61 35.1 1.35
0.004 85.0 14.1 63.0 4.25 51.3 2.63 43.4 1.91
0.006 100 ∞ 70.6 6.00 54.2 2.95 44.2 1.98
0.008 100 ∞ 59.5 3.67 54.2 2.95 45.4 2.07
0.01 100 ∞ 53.6 2.88 54.2 2.95 44.5 2.00
0.02 69.2 5.61 48.9 2.39 54.2 2.95 43.4 1.91
0.03 46.3 2.15 46.3 2.15 53.3 2.85 42.5 1.84
0.04 30.2 1.08 43.9 1.95 51.3 2.63 40.4 1.69
0.05 19.0 0.58 40.5 1.70 49.5 2.45 38.4 1.55
% E = Percentage Extraction D = Distribution Ratio
0.007 M Ascorbic acid recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 122
Table 4 Effect of extractant concentration
Pt(IV) = 200 µg pH = 1.5
Ascorbic acid = 0.007 M Aq.: Org. = 2.5:1
Strippant = Water (2×10 mL)
4-HAP, (M) Percentage extraction, (% E) Distribution ratio, (D)
0.010 26.3 0.89
0.015 32.2 1.18
0.020 39.5 1.63
0.025 46.3 2.15
0.030 53.9 2.92
0.035 61.2 3.94
0.040 70.3 5.91
0.045 80.3 10.1
0.050 92.3 29.9
0.055 100 ∞
0.060* 100 ∞
0.065 100 ∞
0.070 100 ∞
0.080 100 ∞
0.090 100 ∞
0.10 100 ∞
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 123
Table 5 Effect of diluents
Pt(IV) = 200 µg pH = 1.5
Ascorbic acid = 0.007 M Aq.: Org. = 2.5:1
Strippant = Water (2×10 mL) Org. = 0.06 M 4-HAP (10 mL)
Solvent Dielectric
constant
Percentage extraction,
(% E)
Distribution
ratio, (D)
Xylene* 2.30 100 ∞
Toluene 2.38 100 ∞
Chloroform 4.81 93.5 35.9
Dichloromethane 8.93 35.1 1.35
Dichloroethane 1.25 40.7 1.71
Methyl isobutyl
ketone (MIBK)
13.11 63.9 4.42
Cyclohexane 2.02 75.0 7.5
Amyl alcohol 13.90 45.4 2.07
Kerosene 1.8 52.4 2.75
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 124
Table 6 Effect of equilibration time
Platinum(IV) = 200 µg pH = 1.5
Ascorbic acid = 0.007 M Aq.: Org. = 2.5:1
Strippant = Water (2×10 mL) Org. = 0.06 M 4-HAP in xylene (10 mL)
Time in min
Percentage extraction, (%E )
Distribution ratio, ( D )
0.10 55.7 3.14
0.25 100 ∞
0.50 100 ∞
1.0 100 ∞
2.0* 100 ∞
3.0 100 ∞
4.0 100 ∞
5.0 100 ∞
6.0 100 ∞
7.0 100 ∞
8.0 100 ∞
9.0 100 ∞
10.0 100 ∞
15.0 70.3 5.91
20.0 39.2 1.61
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 125
Table 7 Stripping of Pt(IV) from the loaded organic phase
Platinum(IV) = 200 µg pH = 1.5
Ascorbic acid = 0.007 M Aq.: Org. = 2.5:1
Strippant = Water (2×10 mL) Org. = 0.06 M 4-HAP in xylene (10 mL)
Equilibrium time = 2 min
Stripping agents Percentage Extraction, (%E) Distribution ratio, (D)
Ammonia (1-10M) 20.6 0.64
Ammonia buffer (pH10) 27.0 0.92
HCl (1-10M) 52.3 2.74
Water* 100 ∞
HNO3 (1-10M) 55.9 3.16
NaCl (0.1-1.3M) 12.7 0.36
KOH (0.1-1.5M) 42.3 1.83
NaOH (0.1-1.5M) 35.8 1.39
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 126
Table 8 Influence of aqueous to organic volume ratio
Pt(IV) = 200 µg pH = 1.5
Ascorbic acid = 0.007 M Strippant = Water (2×10 mL)
Equilibrium time = 2 min Org. = 0.06 M 4-HAP in xylene (10 mL)
Aqueous to organic
volume ratio
Percentage extraction, (% E)
Distribution ratio, (D)
10:10 100 ∞
20:10 100 ∞
25:10* 100 ∞
30:10 100 ∞
35:10 100 ∞
40:10 100 ∞
50:10 100 ∞
75:10 72.4 6.55
100:10 32.2 1.18
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 127
Table 9 Metal loading capacity of extractant
pH = 1.5 Aq.: Org. = 2.5:1
Ascorbic acid = 0.007 M Strippant = Water (2×10 mL)
Equilibrium time = 2 min Org. = 0.06 M 4-HAP in xylene (10 mL)
Platinum(IV), (μg)
Percentage extraction, (% E)
Distribution ratio, (D)
100 100 ∞
200* 100 ∞
400 100 ∞
800 100 ∞
1000 100 ∞
1500 100 ∞
2000 100 ∞
3000 96.4 66.9
4000 88.5 19.2
5000 79.7 9.81
*Recommended for general extraction procedure
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 128
Table 10 Effect of various foreign ions on percentage extraction
Platinum(IV) = 200 µg pH = 1.5 Aq.: Org. = 2.5:1
Ascorbic acid = 0.007 M Strippant = Water (2×10 mL)
Equilibrium time = 2 min Org. = 0.06 M 4-HAP in xylene (10 mL)
Amount tolerated (mg) Diverse ion added
25 Ca(II), Zn(II), malonate, fluoride
15 U(VI), Mo(VI), Tl(III), tartrate, citrate, oxalate, acetate,
bromide
10 Ti(IV), V(V), Ni(II), Cd(II), Pb(II), Te(IV), Mg(II), Be(II),
EDTA, nitrate
5 Hg(II), Cr(III), Cr(VI), Fe(II), Fe(III), Bi(III), Se(IV),
succinate, salicylate, chloride
3 Rh(III)a,Os(VIII), Au(III)
2 Re(VII), Pd(II)a, Ru(III), Ag(I), Ir(III)
0 Iodide, thiocyanate, thiourea, thiosulphate
aMasked with 10 mg tartrate
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 129
Table 11 Separation and determination of Pt(IV) from binary mixtures
Metal ion Amount
taken(µg)
Average
recovery(%)a
Chromogenic ligand Reference
Pt(IV)
Ru(III)
200
200
99.4
97.9
Thiourea
62
Pt(IV)
Fe(III)
200
60
99.4
99.1
Thiocyanate
61
Pt(IV)
Ni(II)
200
40
99.1
98.5
DMG
61
Pt(IV)
Co(II)
200
300
99.3
98.1
Thiocyanate
61
Pt(IV)
Pd(II)b
200
80
99.1
98.9
Dithizone
61
Pt(IV)
Os(VIII)
200
300
99.1
98.8
Thiourea
62
Pt(IV)
Ir(III)
200
40
98.8
98.2
Hydro bromic acid
61
Pt(IV)
Au(III)
200
200
98.9
98.8
Stannous chloride
62
Pt(IV)
Rh(III)b
200
200
98.9
99.3
Potassium iodide
61
Pt(IV)
Hg(II)
200
100
99.0
99.2
PAN
60
Pt(IV)
Zn(II)
200
60
99.1
99.4
PAR
60
Pt(IV)
Cd(II)
200
10
99.1
98.5
PAR
60
Pt(IV)
Bi(III)
200
300
98.5
97.8
Potassium iodide
61
Pt(IV)
Te(IV)
200
120
98.8
98.5
Bismuthiol II
61
Pt(IV)
Ag(I)
200
120
98.8
98.6
Rhodanine
61
aAverage of five determinations
bMasked with 10 mg tartrate
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 130
Table 12 Separation of platinum(IV) from ternary synthetic mixtures
Composition (µg) Average recoverya (%) RSD (%)
Pt(IV), 200; Ru(III), 200; Ag(I), 120 99.6 0.45
Pt(IV), 200; Rh(III)b, 200; Pd(II)b, 80 99.3 0.67
Pt(IV), 200; Os(VIII), 300; Te(IV), 120 99.9 0.1
Pt(IV), 200; Ir(III), 40; Bi(III), 300 99.7 0.18
Pt(IV), 200; Au(III), 200; Zn(II), 60 99.8 0.13
Pt(IV), 200; Fe(III), 60; Cd(II), 10 99.9 0.15
Pt(IV), 200; Co(II), 300; Hg(II), 100 99.8 0.09
Pt(IV), 200; Ni(II), 40; Ru(III), 200 99.9 0.17
Pt(IV), 200; Hg(II), 100; Os(VIII), 300 99.8 0.09
Pt(IV), 200; Cd(II), 10; Ir(III), 40 99.9 0.09
Pt(IV), 200; Zn(II), 60; Cd(II), 10 99.9 0.17
aAverage of five determinations
bMasked with 10 mg of tartrate
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 131
Table 13 Determination of platinum(IV) in catalystsa
Catalyst Pt(IV)
taken
(µg)
Pt(IV) found using the
proposed methodb (µg)
Average,
% recovery
RSD
(%)
Pt-Pdc-Rhc
monolith on cordierite1
200
199.6
99.8
0.1
Pt–Rhc
monolith on cordierite2
200
199.4
99.7
0.18
Pt catalyst on
alumina3
200
199.2
99.6
0.21
Pt–Pdc–Rhc
catalyst on alumina4
200
199.6
99.8
0.1
Pt–Pdc catalyst on
alumina5
200
199.4
99.7
0.13
Pt–Rhc
catalyst on alumina6
200
199.4
99.7
0.15
aComposition of synthetic mixtures in percentage:
1. Pt, 0.03–0.20; Pd, 0.03–0.15; Rh, 0.005–0.05
2. Pt, 0.03–0.25; Rh, 0.005–0.03
3. Pt, 0.3–0.8
4. Pt, 0.03–0.20; Pd, 0.03–0.150; Rh, 0.005–0.05
5. Pt, 0.03–0.15; Pd, 0.02–0.12
6. Pt, 0.03–0.25; Rh, 0.005–0.03
bAverage of five determinations
cMasked with tartrate
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 132
Table 14 Analysis of platinum(IV) in the anticancer injection and thermocouple wire
Sample Amount taken Amount of Pt(IV)
founda
RSD, (%)
Cytoplatin
(anticancer injection)
200 µg/mL 198.2 µg/mL 0.35
Platinum–rhodiumb
thermocouple wire
(Pt, 87%; Rh, 13%)
200 µg/mL 197.4 µg/mL 0.25
aAverage of five determinations
bMasked with 10 mg tartrate
Table 15 Determination of platinum(IV) in water samples
Sample platinum(IV)
spiked (µg)
platinum(IV)
found (µg)
Average
recoverya
(%)
RSD
(%)
Distilled waterb 200 199.86 99.9 0.04
Tap waterb 200 199.80 99.9 0.06
Waste waterb 200 199.66 99.8 0.29
River waterc 200 199.40 99.7 0.33
aAverage of five determinations
bDepartment of Chemistry, R. R. College, Jath Dist-Sangli
cPanchganga River, Kolhapur
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 133
Fig. 1 Extraction of platinum(IV) as a function of pH
Conditions:
Platinum(IV) = 200 µg, ascorbic acid = 0.007 M, 4-HAP = 0.06 M in xylene,
equilibration time = 2.0 min., strippant = water (2×10 mL),
aq. : org. volume ratio = 2.5 : 1,
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 134
Fig. 2 Extraction as a function of weak organic acid concentration
Conditions:
Platinum(IV) = 200 µg, pH = 1.5, 4-HAP = 0.06 M in xylene, equilibration time = 2.0 min.,
strippant = water (2×10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 135
Fig. 3 Effect of extractant concentration
Conditions:
Platinum(IV) = 200 µg, pH = 1.5, ascorbic acid = 0.007 M, equilibration time = 2.0 min.,
aqueous: organic volume ratio = 2.5 : 1, strippant = water (2×10 mL)
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 136
Fig. 4 Effect of diluents
Conditions:
Platinum(IV) = 200 µg, pH = 1.5, ascorbic acid = 0.007 M, 4-HAP = 0.06 M in variable
solvent, equilibration time = 2.0 min., aq. : org. volume ratio = 2.5 : 1, strippant = water
(2×10 mL)
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 137
Fig. 5 Effect of equilibration time
Conditions:
Platinum(IV) = 200 µg, pH = 1.5, ascorbic acid = 0.007 M, 4-HAP = 0.06 M in xylene,
strippant = water (2×10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 138
Fig. 6 Metal loading capacity of extractant
Conditions:
pH = 1.5, ascorbic acid = 0.007 M, 4-HAP = 0.06 M in xylene, equilibration time = 2 min.,
strippant = water (2×10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 139
Fig. 7 Log-log plot of distribution ratio Log D[Pt(IV)] versus Log C[4-HAP] at fixed ascorbic
acid concentration
Conditions:
Platinum(IV) = 200 µg, ascorbic acid = 0.007 M, pH = 2 and 2.25, equilibration time = 2.0
min., aqueous : organic volume ratio = 2.5 : 1, strippant = water (2×10 mL)
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 140
Fig. 8 Log-log plot of distribution ratio Log D[Pt(IV)] versus Log C[ascorbic acid] at fixed 4-
heptylaminopyridine concentration
Conditions:
Platinum(IV) = 200 µg, pH = 2 and 2.25, 4-HAP = 0.06 M in xylene, equilibration time = 2.0
min., strippant = water (2×10 mL), aq. : org. volume ratio = 2.5 : 1
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 141
References:
[1] F. L. Bernardis, R. A. Grant, D. C. Sherrington, React. Funct. Polym., 65 (2005) 205.
[2] B. Gupta, I. Singh, Hydrometallurgy, 134 (2013) 11.
[3] Platinum Metals Review, Johnson and Matthey Inc., 49 (2005) 118.
[4] Platinum Metals Review, Johnson and Matthey Inc., 53 (2009) 48.
[5] D. L. Trimm, Appl. Catal. A: Gen., 212 (2001) 153.
[6] A. A. Mhaske, P. M. Dhadke, Hydrometallurgy, 61 (2001) 143.
[7] W. Mulak, B. Miazga, A. Szymczycha, Int. J. Miner. Process., 77 (2005) 231.
[8] K. Fujiwara, A. Ramesh, T. Maki, H. Hasegawa, K. Ueda, J. Hazard. Mater., 39 (2007)
146.
[9] J. Cazeaux, M. Lezere, S. Reynaud, International Agency for Research on Cancer: Lyon,
7 (1987) 1.
[10] H. Yamamoto, A. Hayashi, Y. Nakamura, J. Sekizawa, J. Environ. Sci., 12 (2005) 347.
[11] S. Y. Jasim, A. Irabelli, P. Yang, S. Ahmed, L. Schweitzer, Ozone-Sci. Eng., 28 (2006)
415.
[12] R. Mauricio, M. Diniz, M. Petrovic, L. Amaral, I. Peres, D. Barcelo, F. Santana, Environ.
Monit. Assess., 118 (2006) 75.
[13] S. Hann, Z. Stefanka, K. Lenz, G. Stingeder, Anal. Bioanal.Chem., 381 (2005) 405.
[14] M. Fuerhacker, S. N. Mahnik, K. Lenz, N. Weissenbacher, R. W. Mader, P. Krenn, S.
Hann, G. Koellensperger, S. Knasmüller, F. Ferk, M. Uhl, W. Bursch, Proceedings of 3rd
SWIFT-WFD, Barcelona, Spain, (2006) 49.
[15] K. Lenz, S. N. Mahnik, N. Weissenbacher, R. W. Mader, P. Krenn, S. Hann, G.
Koellensperger, M. Uhl, S. Knasmüller, F. Ferk, W. Bursch, M. Fuerhacker, Water Sci.
Technol., 56 (2007) 141.
[16] K. Lenz, G. Koellensperger, S. Hann, N. Weissenbacher, S. N. Mahnik, M. Fuerhacker,
Chemosphere, 69 (2007)1765.
[17] T. Heberer, Toxicol. Lett., 131 (2002) 5.
[18] J. Rajesh, H. Lee, J. Lee, K. Jin-Young, S. Joon-Soo, S. Jeong-Soo, Sep. Sci. Technol., 63
(2008) 184.
[19] D. V. Chavan, P. M. Dhadke, J. Sci. Ind. Res., 62 (2003) 834.
[20] J. Lee, R. Young, B. Kumar, B. Nagaphani, R. Kumar, Sep. Sci. Technol., 73 (2010) 213.
[21] M. Parent, R. Cornelis, R. Dams, Anal. Chim. Acta, 281 (1993) 153.
[22] M. Merdivan, R. S. Aygun, N. Kulcu, Ann. Chim., 80 (2000) 407.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 142
[23] H. Li, Q. Wu, Q. Rong, Zhongshan Daxue Xuebao, Ziran Kexueban, 36 (1997) 77.
[24] K. Ohto, J. Nagata, S. Honda, K. Yoshizuka, K. Inoue, Y. Baba, Solvent Extr. Ion Exch.,
15 (1997) 115.
[25] P. Malik, P. Paiva, Solvent Extr. Ion Exch., 27 (2009) 36.
[26] K. R. Koch, J. E. Yates, Anal. Chim. Acta, 147 (1983) 235.
[27] E. A. Krylova, S. N. Dmitrieva, M. V. Alfimov. S. P. Gromov, T. M. Buslaeva, M. D
Prokhorov, E. V. Volchkova, N. I. Sidorenko, Russ. (2011), RU 2412737 C1 20110227.
[28] V. V. Yakshin, O. M Vilkova, I. G. Tananaev, B. F. Myasoedov, Ross. Khimi. Zh., 54
(2010) 56.
[29] Q. X. Rong, W. J. Duan, H. R. Li, R. N. Chen, S. Q. Liu, J. L. Ye, Z. Huang, X. H. Gu,
Fenxi Shiyanshi, 13 (1994) 37.
[30] T. Yoko, H. Akemi, S. Keiitsu, M. Satomi, M. Akihiko, Bunseki Kagaku, 52 (2003) 725.
[31] K. H. Koenig, M. Schuster, B. Steinbrech, G. Schneeweis, R. Schlodder, Z. Anal. Chem.,
321 (1985) 457.
[32] K. Saito, H. Freiser, Anal. Sci., 5 (1989) 583.
[33] M. Poonma, P. A. Paula, Solvent Extr. Ion Exch., 28 (2010) 49.
[34] Y. Li, G. Gu, X. Zhuang, Xiyou Jinshu Cailiao Yu Gongcheng, 34 (2005) 1830.
[35] R. A. Khisamutdinov, V. V. Potapov, Yu. I. Murinov, V. P. Krivonogov, Zh. Neorg.
Khim., 46 (2001) 513.
[36] L. Pan, Z. Zhang, Miner. Eng., 22 (2009) 1271.
[37] W. Duan, O. Rong, R. Chen, Guijinshu, 19 (1998) 20.
[38] Z. Aneva, S. Arpadzhyan, S. Aleksandrov, Mikrochim. Acta, 73 (1985) 83.
[39] Y. F. Shen, W. Y. Xue, Sep. Sci. Technol., 56 (2007) 278.
[40] E. Jackson, Miner. Eng., 11 (1998) 651.
[41] K. Inoue, I. Nagamatsu, Y. Baba, K. Yoshizuka, Solvent Extr. Ion Exch., 7 (1989) 1111.
[42] K. Saito, I. Taninaka, Y. Yamamota, S. Murakami, A. Muromatsu, Talanta, 51 (2000)
913.
[43] R. A. Khisamutdinov, Yu. I. Murinov, Russ. J. Inorg. Chem., 54 (2009) 156.
[44] R. A. Cherkasov, A. R. Garifzyanov, S. V. Zakharov, A. V. Vinokurov, V. I. Galkin,
Russ. J. Gen. Chem., 76 (2006) 417.
[45] A. R. Garifzyanov, S. V. Zakharov, S. V. Kryukov, V. I. Galkin, R. Asov, Russ. J. Gen.
Chem., 75 (2005) 1208.
[46] M. I. Degtev, N. E. Vorobeva, Yu. A. Makhnev, Zh. Anal. Khim., 44 (1989) 455.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 143
[47] R. A. Khisamutdinov, Yu. I. Murinov, O. V. Shitikova, Zh. Neorg. Khim., 52 (2007)
1041.
[48] Y. Baba, A. arima, S. Kanemaru, M. Iwakuma, T. Oshima, J. chemical eng. Jpn., 44
(2011) 686.
[49] R. A. Khisamutdinov, Yu. I. Murinov, O. V. Shitikova, Russ. J. Inorg. Chem., 52 (2009)
969.
[50] K. Inoue, M. Koba, K. Yoshizuka, M. Tazaki, Solvent Extr. Ion Exch., 12 (1994) 55.
[51] A. Okuda, H. Sawai, S. Ichiishi, J. Shibata, Shigen to Sozai, 116 (2000) 929.
[52] Kosimura, Hideo, Proceedings of Symposium on Solvent Extraction, (1991) 141.
[53] H. Koshimura, T. Suzuki, M. Ichikawa, Jpn. Kokai Tokkyo Koho, (1991).
[54] J. Jianguo, Z. Zuming, M. Jiajun, Guijinshu, 17 (1996) 1.
[55] U. Abdusalam, Z. Yu, M. Mamoun, Solvent Extr. Ion Exch., 21 (2003) 827.
[56] U. Abdusalam, Z. Yu, M. Mamoun, Sep. Sci. Technol., 39 (2004) 3665.
[57] Q. Gaofei, Z. Ying, L. Qin, J. Wenwei, W. Jide, Y. Qin, Yingyong Huaxue, 28 (2011)
1337.
[58] T. I. Tikhomirova, V. I. Fadeeva, G. V. Kudryavtsev, P. N. Nesterenko, V. M. Ivanov, A.
T. Savitchev, N. S. Smirnova, Talanta, 38 (1991) 267.
[59] O. M. Singh, S. J. Singh, S. N. Kim, S. G. Lee, Bull. Korean Chem. Soc., 28 (2007) 115.
[60] H. A. Flaschka, A. J. Bernard, A collection of monographs. Vol. 4, Marcel Dekkar, Inc.
New York, (1972) pp. 4, 79, 164, 134.
[61] Z. Marczenko, Ellis Horwood Limited, Chichester, (1976) pp. 309, 373, 231, 459, 326,
153, 415, 493, 524, 433.
[62] E. B. Sandell, Interscience, New York, 3rd edn, (1965) pp. 702, 781, 505.
[63] H. Li, J. Ding, J. Wu, Guijinshu, 18 (1997) 42.
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 144
Publications
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 145
List of Published Papers in Journals
Sr.
No.
Title Journal Impact
Factor
01
Development of a solvent extraction
system with 4-heptylaminopyridine for
the selective separation of palladium(II)
from synthetic mixtures, catalysts and
water samples
Desalination and Water
Treatment
(Taylor & Francies)
1.272
02
Development of a solvent extraction
system with 4-heptylaminopyridine for
the selective separation of platinum(IV)
from catalysts, anticancer injections
and water samples
Analytical
Methods(RSC)
1.915
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 146
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 147
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 148
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 149
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 150
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 151
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 152
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 153
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 154
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 155
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 156
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 157
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 158
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 159
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 160
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 161
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 162
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 163
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 164
Minor Research Project: By Dr. B. N. Kokare, Raje Ramrao Mahavidyalaya, Jath, Sangli (M.S.)
Page | 165
ACKNOWLEDGEMENT
The author is thankful to the University Grants Commission, Western
Regional Office, Pune, for sanctioning and funding this Minor Research
Project.
It gives me great pleasure to express my sincere sense of gratitude to
Trustees of Shri Swami Vivekananda Shikshan Sanstha, Kolhapur, Principal
Dr. S. Y. Hongekar and I/C Principal Dr. V. S. Dhekale for all their support,
kind co-operation and continuous encouragement.
I wish to express my warm and sincere thanks to Prof. M. A. Anuse,
Professor in Inorganic Chemistry, Shivaji University, Kolhapur for valuable
guidance and co-operation. The author is thankful to Shri. K. K. Rangar Head
of Chemistry Department and colleagues Dr. S. R. Kulal, Mr. D. A. Kumbhar,
Mr. G. D. Salunke, Mr. B. T. Khogare, teaching and administrative staff of the
college for their full co-operation and help in completing this research work.
Dr. S. R. Kokare Dr. B. N. Kokare