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

Contamination Control

Class 10, 100 hoods

Class 100 cleanrooms

Class 10,000 cleanroom

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

Chemical Form: Arsenic

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.

North Carolina Stream Data

Data from North Carolina Geological Survey – ca. 1993

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)

NMR spectrum

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

Peak No. Ret. Time (min) Rel. Ret. Time % of Total Area1 15.19 1 100

Identity/Purity - HPLC

LC analysis:

compare with standards.

0 10 20 30 40Time (min)