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The use of a Transportable Fourier Transform Infrared (FTIR) spectrometer for the direct measurement of solvents in breath and ambient air - I: methanol.
Franzblau A; Levine SP; Burgess LA; Qu S; Schreck RM; D'Arcy JB
Am Ind Hyg Assoc J 1992 Apr; 53(4):221-227
The usefulness of Fourier transform infrared (FTIR) spectroscopy for determining methanol (67561) in expired air was evaluated. Four human volunteers were exposed to 200 parts per million (ppm) methanol vapor for 6 hours in an exposure chamber. End expired (alveolar) air and blood samples were collected before, and at various times during and after exposure. The air samples were analyzed for methanol and carbon-dioxide (124389) using a transportable FTIR spectrometer. Methanol concentrations in the chamber air were analyzed by the spectrometer and a MIRAN infrared analyzer. Carbon-dioxide concentrations in the alveolar air samples were confirmed by a nondispersive infrared (NDIR) analyzer specific for carbon-dioxide. The blood samples were analyzed for methanol by head space gas chromatography. The methanol detection limit of the FTIR spectrometer was 0.50ppm. Methanol concentrations in the ambient air of the chamber were consistently 10ppm higher than those measured by the MIRAN analyzer. FTIR accuracy was assessed by using standard additions of methanol vapor from a compressed gas cylinder. For methanol vapor in ambient air using only concentrations above the 0.50ppm detection limit, the regression line had a correlation coefficient of 0.9998. For methanol vapor in alveolar air analyzed under the same conditions, the regression line had a correlation coefficient of 0.97. The relative standard deviation for seven determinations of alveolar air methanol over the concentration range 13.6 to 21.6ppm was 6.8%. The mean difference in alveolar air carbon-dioxide concentrations measured by the NDIR analyzer and the FTIR spectrometer was -0.092% for concentrations in the range 6.07 to 7.59%. The difference was not statistically significant. The detection limit of methanol in blood was 0.5 micrograms per milliliter. The blood methanol concentrations paralleled those in alveolar air. The authors conclude that FTIR spectroscopy is suitable for determining methanol vapor in alveolar and ambient air, and carbon-dioxide in alveolar air.
NIOSH-Publication; NIOSH-Grant; Grants-other; Alcohols; Organic-vapors; Analytical-methods; Infrared-spectroscopy; Analytical-instruments; Air-samples; Blood-samples
Environmental & Indust Health University of Michigan 1420 Washington Heights Ann Arbor, MI 48109-2029
Issue of Publication
Other Occupational Concerns; Grants-other
American Industrial Hygiene Association Journal
University of Michigan at Ann Arbor, Ann Arbor, Michigan
Page last reviewed: September 22, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division