advances in determinations of metals by icpms, from ultra-small sampling to ultra- trace analysis....
TRANSCRIPT
Advances in Determinations of metals by ICPMS, from ultra-small
sampling to ultra-
trace analysis.
AES Department
Dr. Otto HerrmannTeresa Switzer
May 11, 2009
Historical Background and Application
1980’s atomic absorption – graphite furnace to low ppb and some fractional ppb
LATE 1980’S – introduction of ICPAES with routine 5 to 20 ppb – ultrasonic nebulization to improve about 10x (overlap with graphite
- Pb in boiler water – Bruce
2000+ ICPMS with DRC– routine compromise conditions 0.1 ppb and optimized to 0.01 ppb
- trace metals in moderator water; TIFAC at Darlington
- Gd precipitation and isotopic distribution in moderator
2009 next generation ICPMS – about 100x more sensitive and multiple sample introduction methods
OPERATION AND MAINTENANCE
↑
ICPMS-bare
↑
↑
ICPMS#2 – with attachments
ICPAES
AAS -GRAPHITE
↑
AAS - FLAME
THE NEXT GENERATION STARTREK
Varian 820-MS Instrument Design Features such as 90 degree mirror leading to superior sensitivity and
detection limits
Interference reduction capabilities – new mechanism not fully characterized
Isotope measurement as “radioanalytical” technique (direct -1500yr half-life;
indirect –neutron absorption capability B, Gd); non-active tracers
Laser Ablation- ICP-MS
Use of technique as a semi-quantitative tool and quantitative tool (more
difficult)
“non-destructive” analysis
HPLC and GC interfaces for speciation and matrix separation
Varian 820-MS
LA1 LASER ABLATION
LASER ABLATION SAMPLING ATTACHMENT NEW WAVE 266 NM LASER
LA2 LASER ABLATION +/-
No sample digestion required – direct analysis of solid material.
Relatively “non-destructive” analysis if sample cannot be destroyed.
Interferences and contamination from sample handling and digestion protocols are eliminated
BUT Difficult to calibrate for accurate quantitation
(standards – both physical form and composition critical)
Design special cells for large samples
LA3 Contamination via Handling – 5n AlICP ICP ICP ICPMS LA
Goodfellow Goodfellow Goodfellow Goodfellow Goodfellow
ZrN-old ZrN new drillTi new drillZrN-old NILB <16 <30 <30 <0.2 0.04
Ba <2 <2 <2 0.45
Ca <4 36 2 <2 0.06
Co <6 <5 <5 <0.2
Cr <6 <5 <5 7.08
Cu 29 <4 <2 26.9 0.87
Fe 150 46 21 151 13.1
Mg <2 2 1 4.0 4.7
Mn <2 <2 <2 4.25 0.59
Mo <10 <6 <3 0.64
Nd 0.04
Ni <10 <10 <10 7.25
P <40 <40 <40 <20 0.80
Pb <20 <20 <20 8.42 0.41
Sb <44 0.31 0.04
Sc 0.03
Si <20 <20 <20 <20 0.14
Sn <8 <8 <8 1.59 0.27
V <10 <10 <10 <2 0.02
Zn <2 11 <2 3.74
Zr <6 0.80 0.13
LA4 High Purity Aluminum (5n) Analysis by LA-ICPMS
ppm LA LA LASample 09-01551-1 09-01551-2 09-01551-3
isotope Goodfellow Ekain - China Giang&I -China
As75 <0.02 0.042 <0.02B11 0.039 0.037 0.035Ca43 0.064 0.072 0.088Ce140 0.645 0.220 0.792Cu65 0.863 0.940 0.869Fe57 13.080 21.408 20.951Mg24 4.688 5.694 5.519Mn55 0.585 1.012 0.750Nd146 0.044 0.031 0.038P31 0.798 1.121 1.262Pb208 2.275 0.170 2.393Sb121 0.039 0.025 0.028Sc45 0.032 0.042 0.043Si28 0.136 0.189 0.192Si29 0.110 0.155 0.180Sn118 0.267 0.428 0.271V51 0.017 0.019 0.031Zr90 0.127 0.040 0.647TOTAL 23.809 31.645 34.0895n=99.999% = <10 ppm impurities
LA5 LASER ABLATION Faults versus Bulk Analysis
20um to 600 um spot size determined by application Ablate in preset pattern – target vs. scan
PENNY WITH TARGET MARKING
BURN
BURN TRACK-20um
Combined Techniques
HPLC-ICPMS best known
- speciation (AS+3, AS+5, organo-As such as arsenobetaine); EPA legislation tributyl tin
- matrix removal or species concentration
GC-ICPMS – volatile species; Hg species; organometallics; least familiar