Supporting Information

Composition of the surfactant Aerosol OT and its influence on the properties of an agrochemical formulation

Johannes Glaubitz1,2, Karl Molt, Torsten C. Schmidt* 1

1 University Duisburg-Essen. Instrumental Analytical Chemistry. Universitätsstr. 5.

45141 Essen. Germany

2 Bayer CropScience, BCS-D-FT-A&S, Alfred-Nobel-Straße 50, 40789 Monheim am Rhein

* Corresponding author:

E-mail: torsten.schmidt@uni-due.de

Phone: +49 201 183-6774

Fax: +49 201 183-6773

Table of Contents

1. Sample for testing on mass calibration of ToF-MS..................................................................................6

2. Content of diester 1, monoester 2 and monoester 3 in different production batches of commercially available AOT of different suppliers............................................................................................................... 8

3. Sedimentation in trail storage formulation samples.............................................................................10

4. Centrifugation of a model agrochemical formulation containing AOT of supplier A1............................10

5. Results of the analysis of AOT of different production batches for inorganic anions and cations of different suppliers........................................................................................................................................ 11

6. Analysis of the composition of the solvent in AOT on differences between the suppliers.....................18

7. Statistical evaluation of the usefulness of the contents of diester 1 and monoester 2 and 3 for product identification............................................................................................................................................... 22

List of Figures

1

Figure S 1: Test on sedimentation after 0.5 a storage at room temperature of a model

agrochemical formulation containing AOT of supplier A1, B and D. Increasing amount of

visible sediment from supplier A1 to supplier D......................................................................10

Figure S 2: Chormatographic seperation of the cations Na+and Ca2+(a) and the anions Cl-, NO3-

and SO42-via ion chromatography..............................................................................................13

Figure S 3: Content of (a) Na+, (b) NH4+, (c) Ca2+, (d) Cl-, (e) NO3

- and (f) SO42- in selected

production batches of AOT of supplier A1, B, C and D displayed as box-plots......................17

Figure S 4: Chromatographic separation of the light-aromatic naphtha solvent in AOT, shown

in (a) are the earlier eluting and in (b) the late eluting compounds..........................................19

Figure S 5: Comparison of the chromatographic pattern of the light-aromatic naphtha solvent

of selected production batches of AOT of the suppliers A1, C and D. The analysis of the

solvent was conducted on GC-MS............................................................................................22

2

List of Tables

Table S 1: Retention time and exact masses for compounds in the test sample for checking on

mass calibration...........................................................................................................................4

Table S 2: Content of diester 1 and monoester 2 and 3 in AOT together with their expanded

measurement uncertainty. Analysis of five independently weight samples each batch number

averaged. The expended measurement uncertainty is calculated according to GUM

encompassing 95% of the distribution of values [1]...................................................................6

Table S 3: Content of diester 1, monoester 2 and monoester 3 in sediment given as percentage

of the AOT-content in the formulation. The sediment was obtained after centrifugation of the

modell agrochemical formulation containing AOT of supplier A1. Each value is the average

of five replicates analyses, given together with its interval of confidence of 95%.....................9

Table S 4: Content of Na+, Ca2+, Cl-, NO3- and SO4

2-in selected production batches of AOT of

supplier A1, supplier B, supplier C and supplier D. Those ions, which contents were below

the LOQ of the used method were indicated with “<LOQ”......................................................12

Table S 5: Compounds in the light-aromatic naphtha solvent in AOT, which were identified

via spectra library. Shown are the most likely hits according to retention time and spectrum.17

3

1. Sample for testing on mass calibration of ToF-MS

The retention times and exact masses for the compounds in the test sample for checking on

mass calibration of the used ToF-MS are given in Table S 1.

Table S 1: Retention time and exact masses for compounds in the test sample for checking on mass

calibration

Compound tN/min Exact mass/amuImidacloprid 2.0 254.0450Thiacloprid 2.5 252.0236Tebuconazole (1.Isomer) 4.3 307.1451Triadimenol 4.6 295.1088Tebuconazole (2.Isomer) 4.9 307.1451Distyrylethoxylate-5-EO 5.8 522,2981Distyrylethoxylate-6-EO 5.8 566,3244Distyrylethoxylate-7-EO 5.8 610,3506Distyrylethoxylate-8-EO 5.8 654,3768Distyrylethoxylate-9-EO 5.8 698,4030Distyrylethoxylate-10-EO 5.8 742,4292Distyrylethoxylate-11-EO 5.8 786,4554Distyrylethoxylate-12-EO 5.8 830,4816Distyrylethoxylate-13-EO 5.8 874,5079Distyrylethoxylate-14-EO 5.8 918,5341Distyrylethoxylate-15-EO 5.8 962,5603Distyrylethoxylate-16-EO 5.8 1006,5865Distyrylethoxylate-17-EO 5.9 1050,6127Distyrylethoxylate-18-EO 5.9 1094,6389Distyrylethoxylate-19-EO 5.9 1138,6651Distyrylethoxylate-20-EO 5.9 1182,6914Distyrylethoxylate-21-EO 5.9 1226,7176Distyrylethoxylate-22-EO 5.9 1270,7438Distyrylethoxylate-23-EO 5.9 1314,7700Distyrylethoxylate-24-EO 5.9 1358,7962Distyrylethoxylate-25-EO 5.9 1402,8224Distyrylethoxylate-26-EO 5.9 1446,8486Distyrylethoxylate-27-EO 5.9 1490,8749Distyrylethoxylate-28-EO 5.9 1534,9011Distyrylethoxylate-29-EO 5.9 1578,9273Distyrylethoxylate-30-EO 5.9 1622,9535Nonylphenolethoxylate-5-EO 6.6 440,3138Nonylphenolethoxylate-6-EO 6.3 484,3400Nonylphenolethoxylate-7-EO 6.2 528,3662Nonylphenolethoxylate-8-EO 6.2 572,3924Nonylphenolethoxylate-9-EO 6.2 616,4186Nonylphenolethoxylate-10-EO 6.2 660,4449Nonylphenolethoxylate-11-EO 6.2 704,4711Nonylphenolethoxylate-12-EO 6.2 748,4973Nonylphenolethoxylate-13-EO 6.2 792,5235Nonylphenolethoxylate-14-EO 6.2 836,5497Nonylphenolethoxylate-15-EO 6.2 880,5759

4

Nonylphenolethoxylate-16-EO 6.2 924,6022Nonylphenolethoxylate-17-EO 6.2 968,6284Nonylphenolethoxylate-18-EO 6.2 1012,6546Nonylphenolethoxylate-19-EO 6.2 1056,6808Nonylphenolethoxylate-20-EO 6.2 1100,7070Nonylphenolethoxylate-21-EO 6.2 1144,7332Nonylphenolethoxylate-22-EO 6.2 1188,7594Nonylphenolethoxylate-23-EO 6.2 1232,7857Nonylphenolethoxylate-24-EO 6.2 1276,8119Nonylphenolethoxylate-25-EO 6.2 1320,8381Nonylphenolethoxylate-26-EO 5.9 1364,8643Nonylphenolethoxylate-27-EO 5.9 1408,8905Nonylphenolethoxylate-28-EO 5.9 1452,9167Nonylphenolethoxylate-29-EO 5.9 1496,9429Nonylphenolethoxylate-30-EO 5.9 1540,9692Tristyrylethoxylate-5-EO 5.9 626,3607Tristyrylethoxylate-6-EO 5.9 670,38695Tristyrylethoxylate-7-EO 5.9 714,4132Tristyrylethoxylate-8-EO 6.5 758,4394Tristyrylethoxylate-9-EO 5.9 802,4656Tristyrylethoxylate-10-EO 5.9 846,4918Tristyrylethoxylate-11-EO 6.0 890,5180Tristyrylethoxylate-12-EO 6.0 934,5442Tristyrylethoxylate-13-EO 6.0 978,5705Tristyrylethoxylate-14-EO 6.0 1022,5967Tristyrylethoxylate-15-EO 6.0 1066,6229Tristyrylethoxylate-16-EO 6.0 1110,6491Tristyrylethoxylate-17-EO 6.0 1154,6753Tristyrylethoxylate-18-EO 6.0 1198,7015Tristyrylethoxylate-19-EO 6.0 1242,7278Tristyrylethoxylate-20-EO 6.0 1286,7540Tristyrylethoxylate-21-EO 5.9 1330,7802Tristyrylethoxylate-22-EO 5.9 1374,8064Tristyrylethoxylate-23-EO 5.9 1418,8326Tristyrylethoxylate-24-EO 5.9 1462,8588Tristyrylethoxylate-25-EO 5.9 1506,8850Tristyrylethoxylate-26-EO 5.8 1550,9113Tristyrylethoxylate-27-EO 5.8 1594,9375Tristyrylethoxylate-28-EO 5.8 1638,9637Tristyrylethoxylate-29-EO 5.8 1682,9899Tristyrylethoxylate-30-EO 5.8 1727,0161

5

2. Content of diester 1, monoester 2 and monoester 3 in different production

batches of commercially available AOT of different suppliers

In Table S 2 were given the content of diester 1 and the monoesters 2 and 3 in AOT of at least

eight production batches each investigated supplier A, B, C and D. The given data for each

production batch are average values of five independently weighed repetition analyses after

the removal of outliers with a Grubbs outlier test. The displayed data is given together with its

interval of confidence of 95%.

Table S 2: Content of diester 1 and monoester 2 and 3 in AOT together with their expanded measurement

uncertainty. Analysis of five independently weight samples each batch number averaged. The expended

measurement uncertainty is encompassing 95% of the distribution of values.

Sample [Supplier-Batch No.]

AOT(w/w /%)

Monoester 2(w/w /%)

Monoester 3(w/w /%)

a-1 62.9 ± 1.2 1.3 ± 0.02 0.72 ± 0.02a-2 58.6 ± 1.2 1.5 ± 0.04 0.58 ± 0.01a-3 60.2 ± 0.6 1.7 ± 0.02 0.93 ± 0.01a-4 61.3 ± 3.3 1.2 ± 0.05 0.48 ± 0.02a-5 62.4 ± 2.1 2.0 ± 0.04 0.82 ± 0.03a-6 61.2 ± 0.9 1.3 ± 0.01 0.72 ± 0.01a-7 62.6 ± 1.2 1.5 ± 0.03 0.83 ± 0.01a-8 62.2 ± 1.1 1.3 ± 0.03 0.69 ± 0.01

A-1 64.5 ± 1.0 2.8 ± 0.02 1.7 ± 0.03A-2 57.8 ± 1.0 2.3 ± 0.05 2.1 ± 0.05A-3 58.0 ± 1.6 2.6 ± 0.05 2.0 ± 0.04A-4 56.3 ± 1.0 2.4 ± 0.04 1.9 ± 0.01A-5 60.6 ± 0.6 2.5 ± 0.08 1.8 ± 0.05

B-1 65.8 ± 0.7 0.82 ± 0.01 0.15 ± 0.004B-2 65.0 ± 3.5 0.58 ± 0.02 0.26 ± 0.01B-3 65.3 ± 2.1 0.80 ± 0.02 0.15 ± 0.003B-4 73.1 ± 1.3 1.2 ± 0.03 0.36 ± 0.01B-5 61.3 ± 1.1 1.3 ± 0.04 0.28 ± 0.02B-6 62.1 ± 0.7 1.0 ± 0.01 0.31 ± 0.01B-7 63.0 ± 1.0 0.88 ± 0.01 0.21 ± 0.01B-8 71.3 ± 1.0 1.2 ± 0.03 0.30 ± 0.01

6

C-1 61.4 ± 1.0 3.2 ± 0.06 0.67 ± 0.03C-2 58.8 ± 0.7 2.5 ± 0.06 1.0 ± 0.02C-3 55.7 ± 0.9 3.4 ± 0.02 1.0 ± 0.02C-4 62.9 ± 0.6 2.5 ± 0.05 1.5 ± 0.03C-5 60.1 ± 0.7 3.3 ± 0.05 0.73 ± 0.02C-6 59.0 ± 0.8 2.3 ± 0.04 0.60 ± 0.01C-7 57.1 ± 0.9 2.4 ± 0.04 0.53 ± 0.01C-8 58.7 ± 0.9 2.4 ± 0.03 0.54 ± 0.01

D-1 63.9 ± 0.3 3.8 ± 0.09 2.7 ± 0.09D-2 61.6 ± 1.1 3.4 ± 0.11 2.4 ± 0.03D-3 64.8 ± 1.0 4.1 ± 0.06 2.7 ± 0.08D-4 65.1 ± 0.9 4.0 ± 0.09 2.5 ± 0.04D-5 64.1 ± 0.7 3.9 ± 0.08 2.3 ± 0.07D-6 61.2 ± 1.3 4.1 ± 0.06 2.8 ± 0.04D-7 64.6 ± 0.2 3.9 ± 0.05 2.0 ± 0.07D-8 64.2 ± 1.0 3.8 ± 0.03 2.3 ± 0.03D-9 65.0 ± 1.0 4.0 ± 0.03 2.0 ± 0.03D-10 64.4 ± 0.5 3.1 ± 0.08 2.0 ± 0.05D-11 65.3 ± 0.7 3.2 ± 0.07 2.2 ± 0.05D-12 65.2 ± 0.4 3.0 ± 0.06 2.1 ± 0.04D-13 65.2 ± 0.8 2.8 ± 0.09 1.9 ± 0.05D-14 60.9 ± 0.7 2.9 ± 0.21 1.8 ± 0.09D-15 63.3 ± 0.4 2.9 ± 0.05 2.0 ± 0.04D-16 62.5 ± 0.8 3.3 ± 0.05 2.2 ± 0.06

7

3. Sedimentation in trail storage formulation samples

The observed sediment in the formulation samples after storage was photographed from above

and shown in Figure S 1.

Figure S 1: Test on sedimentation after 0.5 a storage at room temperature of a model agrochemical

formulation containing AOT of supplier A1, B and D. Increasing amount of visible sediment from supplier

A1 to supplier D

4. Centrifugation of a model agrochemical formulation containing AOT of

supplier A1

A model agrochemical formulation containing AOT of supplier A1 was centrifuged with a

HEREAUS Labofuge 400 with 3000 r/min. The supernatant was removed and the sediment

analyzed on diester 1 and monoester 2 and monoester 3. The results of the analyses given as

percentage of the AOT-content in the formulation are shown in Table S 3. Each value is the

average of five replicate analyses given together with its interval of confidence of 95%.

8

Table S 3: Content of diester 1, monoester 2 and monoester 3 in sediment given as percentage of the AOT-

content in the formulation. The sediment was obtained after centrifugation of the model agrochemical

formulation containing AOT of supplier A1. Each value is the average of five replicates analyses, given

together with its interval of confidence of 95%.

AOT(w/w /%)

Monoester 2(w/w /%)

Monoester 3(w/w /%)

Sediment sample 236.0 ± 36.2 1.8 ± 0.1 0.9 ± 0.08

5. Results of the analysis of AOT of different production batches for inorganic

anions and cations of different suppliers

Selected production batches of AOT of supplier A1, B, C and D were investigated on

difference in their content of inorganic cations and anions, which are known to influence both

ionic and non-ionic surfactants [1;2]. The samples were screened on the content of the cations

Li+ Na+, NH4+, K+, Mg2+ and Ca2+, as well as, the anions of Br-, Cl-, F-, NO3

-, PO43- and SO4

2-.

Variations in the content of inorganic ions between the suppliers of AOT may explain the

differences observed in sedimentation behavior after storage of a model agrochemical

formulation containing AOT of either supplier A1, B or D.

Analysis was conducted on an ICS 2000 ion chromatography instrument from Dionex.

Chromatographic separation of the cations was performed with an IonPa CS12A column (250

x 2.0 mm). For mobile phase methanesulfonic acid (MSA) was taken. The sample was

injected with a volume of 5.0 µL and gradient elution was applied for separation of the target

analytes. Starting with a concentration of 30 mM MSA and raised to 40 mM in 10 min,

lowered to 30 mM MSA in 1.0 min to 30mM MSA by column flushing and equilibration

afterwards. Total run time was 15 min with a flow of 0.25 mL/min and a column temperature

of 30°C.

9

For chromatographic separation of the anions an IonPac AS11 HC column (250 mm x

2.0 mm) was used. As mobile phase water plus 30mM KOH was taken. The sample was

injected with 2.5 µL and the target analytes were eluted isocratically. Total run time was

15 min with a flow of 0.38 mL/min and column temperature of 30 °C. For detection an

electrochemical detector connected upstream with a suppressor was used.

For analysis of the cations Dionex Six Cation-II Standard was used, containing lithium

(c(Li+) = 50 mg/L), sodium (c(Na+) = 201 mg/L), ammonium (c(NH4+) = 251 mg/L),

potassium (c(K+) = 501 mg/L), magnesium (c(Mg2+) = 250 mg/L) and calcium (c(Ca2+) =

50 mg/L). This solution had to be further diluted by 1:10 (v/v) diluted to obtain the stock

solution for the analysis of cations.

For the analysis of the anions a commercially available multi-element ion chromatography

anion standard supplied by Fluka was used as standard solution containing, bromide (c(Br-) =

20 mg/L), chloride (c(Cl-) = 10 mg/L), fluoride (c(F-) = 3 mg/L), nitrate (c(NO3-) = 20 mg/L),

phosphate (c(PO43-) = 20 mg/L) and sulfate (c(SO4

2-) = 20 mg/L).

For preparation of the standard solutions the both stock solutions were diluted to fit the

concentration range 20 mg/L to 1 mg/L.

10

For analysis the light aromatic solvent in AOT was evaporated. An amount of 100 mg of the

remainder was diluted with 50 mL of a mixture of 95/5 (v/v) water/methanol. The obtained

solution could be directly injected without further dilution accepted for the analysis of Na+,

where the sample solution had to be diluted 1:10 (v/v) to be inside the linear range.

Of all investigated inorganic ions only the contents of Na+, Ca2+, Cl-, NO3- and SO4

2- were

above the limit of quantification (LOQ) of 1 mg/L of the used analytical method. As this

LOQ corresponds to a content of 0.05 % (w/w) in AOT with the given sample preparation, no

further attempts were made to detect the other inorganic ions screened for, as their content

was considered negligible. In Figure S 2 is shown the chromatographic separation of the target

cation (a) and anions (b) for the analysis of the production batch a-1.

(a)

(b)

Figure S 2: Chromatographic separation of the cations Na+ and Ca2+(a) and the anions Cl-, NO3- and SO4

2-

via ion chromatography.

11

The obtained results are shown in Table S 4 and are visualized as box-plots in were indicated

with “<LOQ”. (a) for Na+, in (b) for Ca2+, in (c) for Cl-, in (d) for NO3- and in (e) for SO4

2-.

Those ions, which contents were below the LOQ of the used method, were indicated with

“<LOQ” and were not considered for the box-plot figures.

Table S 4: Content of Na+, Ca2+, Cl-, NO3- and SO4

2-in selected production batches of AOT of supplier A1,

supplier B, supplier C and supplier D. Those ions, which contents were below the LOQ of the used method

were indicated with “<LOQ”.

Sample[Supplier-Batch No.]

Na+

(w/w /%)Ca2+

(w/w /%)Cl-

(w/w /%)NO3

-

(w/w /%)SO4

2-

(w/w /%)a-1 4.7 0.07 < LOQ < LOQ 0.5a-2 5.3 <LOQ 0.06 0.05 0.3a-3 5.2 0.1 0.08 0.09 0.6a-4 7.5 0.1 0.05 0.07 0.4a-5 5.1 0.1 0.06 0.08 0.7a-6 3.8 <LOQ < LOQ < LOQ 0.4a-7 3.7 0.08 < LOQ < LOQ 0.3a-8 4.8 <LOQ < LOQ < LOQ 0.5

B-1 5.0 <LOQ 0.09 0.1 0.4B-2 5.2 <LOQ 0.06 0.08 0.3B-3 4.8 <LOQ 0.06 0.07 0.3B-4 5.4 <LOQ 0.16 0.2 0.5B-5 4.9 <LOQ 0.06 0.07 0.5B-6 5.3 <LOQ 0.14 0.1 0.5B-7 5.2 <LOQ 0.14 0.1 0.6B-8 5.4 <LOQ 0.14 0.2 0.5

C-1 5.7 <LOQ < LOQ < LOQ 0.3C-2 3.0 0.2 < LOQ < LOQ 0.2C-3 4.5 0.2 < LOQ 0.05 0.3C-4 3.5 0.09 0.05 0.07 0.3C-5 6.0 0.1 0.06 0.08 0.4C-6 4.4 0.08 < LOQ 0.05 0.3C-7 4.9 0.07 < LOQ < LOQ 0.4C-8 5.9 <LOQ < LOQ < LOQ 0.4

D-1 4.2 0.1 0.05 0.07 0.4D-2 6.9 0.1 0.2 0.07 0.4D-3 5.9 0.07 < LOQ < LOQ 0.3D-4 6.8 0.09 0.05 < LOQ 0.4D-5 5.7 0.1 0.1 < LOQ 0.3D-6 5.5 0.06 0.1 < LOQ 0.3

12

D-7 5.8 <LOQ 0.07 < LOQ 0.3D-8 2.7 0.08 0.05 0.05 0.3D-9 3.8 0.05 0.1 0.05 0.3D-10 5.3 0.2 0.08 0.1 0.3D-11 5.5 0.1 0.05 0.05 0.4D-12 4.7 0.1 0.05 0.05 0.3D-13 5.7 0.07 0.05 0.05 0.6D-14 5.7 0.3 0.2 0.1 0.4D-15 5.6 0.2 0.06 0.08 0.5D-16 5.3 0.1 0.06 0.08 0.4

a)

13

(b)

(c)

14

(d)

(e)

Figure S 3: Content of (a) Na+, (b) NH4+, (c) Ca2+, (d) Cl-, (e) NO3

- and (f) SO42- in selected production

batches of AOT of supplier A1, B, C and D displayed as box-plots.

15

As shown the content of the investigated inorganic ions, Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3

-

and SO42-in AOT was not different between the supplier A1, B, C and D. Therefore the

observed differences in the physico-chemical properties of a model agrochemical formulation,

containing AOT of either supplier A1, B or D, could not be explained by differences in the

content of inorganic ions.

6. Analysis of the composition of the solvent in AOT on differences between

the suppliers

Selected production batches of supplier A1, C and D were analyzed via GC-MS, to

investigate, if there are differences in the composition of the light-aromatic naphtha solvent in

which the actual surfactant of AOT, diester 1, is solved in, between the different suppliers.

The analysis was performed via gas chromatography coupled to mass spectrometry with

electron impact ionization on an Agilent 5973 GC/MS. The sample was injected with 0.2 µL,

with a split of 1:60 (GC:waste) on a HP-5 capillary column of Agilent with an inner diameter

of 0.18 mm, a length of 20 m and film thickness of 0.18 mm. Separation of the analytes was

achieved with a temperature gradient, starting with 60 °C, raising temperature to 200 °C in 28

min. For column cleaning the temperature was then raised to 280 °C in 4 min and held for 3

min at 280 °C. Total run time was 35 min with N2-gas stream set at 150 kPa constant pressure.

The Inlet temperature was set at 260 °C, the aux temperature at 280 °C, the temperature in the

MS inlet at 250°C and in the MS quadrupole at 150 °C.

An amount of 20 mg each AOT sample was solved in 50 mL of a mixture of 1:1 (v/v)

ACN/H2O. The obtained solution was then injected into the GC-MS, without further dilution

or treatment.

16

The main components of the light-aromatic naphtha solvent was chromatographically

separated and identified via a spectra library. The chromatographic separation is shown in

Figure S 4 (a) for the early eluting and in Figure S 4 (b) for the late eluting compounds. The

most likely hit regarding retention time and spectrum for the main components are displayed

in .

(a)

(b)

Figure S 4: Chromatographic separation of the light-aromatic naphtha solvent in AOT, shown in (a) are

the earlier eluting and in (b) the late eluting compounds.

17

Table S 5: Compounds in the light-aromatic naphtha solvent in AOT, which were identified via spectra

library. Shown are the most likely hits according to retention time and spectrum.

Retention time [min] Compound2.48 1,3-dimethyl-benzene2.79 (1-methylethyl)-benzene3.15 Propyl-benzene3.30 1-ethyl-3-methyl-benzene3.42 1-ethyl-2-methly-benzene3.95 (2-methylpropyl)-benzene3.99 (1-methylpropyl)-benzene4.23 1, 2, 3-trimethylbenzene4.43 Indane4.66 1, 3-diethyl-benzene4.69 1-methly-3-propyl-benzene4.77 Diethyl-benzene4.83 4-ethyl-1,2-dimethyl-benzene4.88 1, 2-diethyl-benzene4.98 1-methly-4-propyl-benzene5.18 2-ethyl-1, 4-dimethyl-benzene5.34 2-ethyl-1 ,3-dimethyl-benzene5.97 1, 2, 4, 5-teramethly-benzene6.06 1, 2, 3, 4-teramethly-benzene7.19 alpha, 4-diemethyl-benzene-methanol8.99 6-methylheptyl ester 2- propionic acid29.24 Bis(2-ethylhexyl) maleate30.24 1 ,2-Cyclohexanedione

As shown the main compounds identified are benzyl derivates of benzene, which confirms the

characterization of the light-aromatic naphtha solvent by its supplier [3;4]. 8 different

production batches each supplier A1, C and D were analyzed accordingly, on the composition

of their light-aromatic solvent. Exemplary, are given in Figure S 5 the results for one

production batch of AOT each supplier, as variations between the analyzed production

batches for suppliers were not detected. Shown are separately the range of time 0-10 min in

A1-1, C-1 and D-1 and the time range 10-35min in A1-2, C-2 and D-2.

18

(A1-1)

(A1-2)

(C-1)

19

(C-2)

(D-1)

(D-2)

Figure S 5: Comparison of the chromatographic pattern of the light-aromatic naphtha solvent of selected

production batches of AOT of the suppliers A1, C and D. Shown are separately the retention time range

0-10 min (A1-1), C-1 and D-1) and 10-35 min (A1-2, C-2 and D-2). The analysis of the solvent was

conducted on GC-MS

The compounds listed in were found for all three suppliers. Observed were, however,

differences between the investigated suppliers of AOT regarding the abundance of some

compounds in the retention time window 2.0-7.0 min.

20

7. Statistical evaluation of the usefulness of the contents of diester 1 and

monoester 2 and 3 for product identification

After having analyzed the content of diester 1, monoester 2 and monoester 3 in AOT samples

from production batches of different suppliers the question arose if in the future such

analytical data could be potentially helpful for identifying the supplier from which an

unknown sample originates. The corresponding statistical analysis was performed with R, a

language and environment for statistical computing and graphics [5]. Therefore two further

documents are provided in the Supporting Information. The first one is the document

"evaluation.pdf" which explains the statistical evaluation in detail. The second one is a stand-

alone R script (evaluation.R) which can be immediately executed by the reader. This needs

the input files "data_set_1.txt" (samples from batches of various suppliers) and

"data_set_2.txt" (trial storage formulation samples) which are also included in the Supporting

Information.

Reference List

1. Porter MR (1994) Handbook of Surfactants. vol. 2 Chapman & Hall, Glasgow2. Tadros TF (2008) In: Applied Surfactants, Principles and Applications. Wiley-VCH,

Weinheim.3. Shell Chemicals (Accesed: December 2013) Material Safety data sheat ShellSol A100

http://aglayne.com/wp-content/uploads/2010/10/Shellsol-A-100.pdf.4. Exxon Mobil Chemical (Accesed: December 2013) Material safety data sheat Solvesso

100 https://www.exxonmobilchemical.com/Chem-English/Files/Resources/aromatic-100-product-safety-summary.pdf

5. R Development Core Team (2012) R: A Language and Enviroment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria, ISBN 3-900051-07-0.

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