applications of analytical chemistry at rti international argon plasma instruments atomic emission...
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Applications of Analytical Chemistryat RTI International
Argon plasma instruments Atomic Emission (ICP-AES) – 3
Quadrupole Mass Spectrometers (ICP-MS) - 2
Sector Field Mass Spectrometer (SFICP-MS) -1
FluorescenceCold Vapor (for Hg)
Hydride Generation (for As, Se, etc.)
Absorption
Analytical Support
RTI has performed major component, trace and ultra-trace level organic & inorganic analyses in support of variety of studies…
Animal toxicology/ADME studies - Bulk chemical characterization, impurity analysis, tissue burden analysis.
Human exposure studies - (Hg in hair; Pb in blood; As, Cd, Se, Cu, etc. in blood and plasma, etc.)
Environmental studies – drinking water, food, air samples, sediments, etc.
Atomic Spectrometry at RTI International
Essential Trace Metals: Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Se…?
Assessment of Human Exposure to Arsenic
Exposure:
Ingestion - Drinking water and food.
Inhalation – negligible
Internal dose:
Urine analysis
Hair analysis
Toxicity of Species:
As(III), As(V), AsB, AsC, MMA, and DMA
Interferences – Atomic Masses
High-Resolution ICP-MS solves many problems…
…but is not a magic bullet
As=74.921594
ArCl=39.962384+34.965903=74.928287
As
As
73.9216 Mass Resolution 75.9605 74.9150 Mass Resolution 74.9670
Isobaric Interference on 75As
Nominal[As]
0 ppm Chloride 5000 ppm Chloride Urine Matrix
Calculated[As]
% Bias Calculated[As]
% Bias Calculated[As]
% Bias
0 0.06 NA -0.06 NA 0 NA
0.5 0.51 2.0 0.57 14 0.55 10
1.0 1.06 6.0 0.94 -6.0 1.05 5.0
5.0 4.85 -3.0 5.06 1.2 4.87 -2.6
30 30.0 0 30.0 0 30.0 0
Calibration Standard – Urine matrix
Chromatogram 10ppb calibration standard (urine).
Key:
1- AsB, 2 - As3+
3-DMA, 4-AsC
5-MMA, 6-As5+
IS - Internal standard (Potassium Hexahydroxy Antimonate V).
0
2000
4000
6000
8000
Arsen
ic Sign
al Inte
nsity (
cps)
0
2000
4000
6000
8000
Antim
ony S
ignal I
ntensi
ty (cps
)
0 5 10 15 20 25 30 35 Retention Time (min.)
1
2
3
4
5
6
IS
0
100
200
300
400
500
600
700
Arsen
ic Sign
al Inte
nsity (
cps)
0 5 10 15 20 25 30 Retention Time (min.)
1
2
3
Urine sample. 1-AsB, 2-DMA, and 3-MMA.
L-ephedrine
Mol wt.: 165.23
Mol formula: C10H15NO
Analytical work:
Identification/Confirmation
Impurity determination
Identity - FTIR
Assignments: 3470-N-H Stretch; 3298-N-H Stretch; 3085-O-H Stretch; 2979- Aromatic C‑H Stretch; 1491-N‑CH3 Bend; 1450-N‑CH3 Bend; 1373-N‑CH3 Bend; 1353-C‑O Stretch; 1136-C‑N Stretch; 1089-O‑H Stretch; 983-C‑H Bend; 750-Aromatic C‑H Bend; 702-Aromatic C‑H Bend.
-30
-20
-10
0
10
20
30
40
50
60
70
80
%T
500 1000 1500 2000 2500 3000 3500 4000
Wavenumbers (cm-1)
Identity - NMR
Chemical Shift (ppm)
MultiplicityIntegral Ratio
Assignment
0.85-0.89 d 3.0 a
2.52-2.54 s 3.1 b
2.69Exchange
peak2.5 *
2.82-2.90 m 1.4 c
4.84-4.86 s 1.0 d
7.28-7.36 s 5.0 e
7.25-7.27 - solvent