FTIRFourier Transform Infrared

FTIR

IntroductionIntroduction

Air monitoring data is useful for:Air monitoring data is useful for:** Assessing the health risks to the public and response Assessing the health risks to the public and response

workers.workers.

** Selecting personal protective equipment.Selecting personal protective equipment.

** Delineating areas where protection is needed.Delineating areas where protection is needed.

** Determining actual or potential effects on the environment.Determining actual or potential effects on the environment.

** Selecting actions to mitigate the hazards safely and Selecting actions to mitigate the hazards safely and effectively.effectively.

FTIR

Toxic atmosphere monitoring is done to:Toxic atmosphere monitoring is done to:

** identify airborne concentrations that could pose a identify airborne concentrations that could pose a toxic risk to response workers and the public.toxic risk to response workers and the public.

** evaluate the need for and type of personal evaluate the need for and type of personal protective equipment.protective equipment.

** set up work zones or areas where contaminants are set up work zones or areas where contaminants are or are not present. Colorimetric Indicator Tubesor are not present. Colorimetric Indicator Tubes

Characteristics of Air Monitoring

To be useful air monitoring instruments To be useful air monitoring instruments must be:must be:

** Portable and rugged.Portable and rugged.

** Easy to operate.Easy to operate.

** Inherently safe.Inherently safe.

** Able to generate reliable and useful Able to generate reliable and useful results.results.

Reliable and Useful Results

The response time, sensitivity, selectivity, The response time, sensitivity, selectivity, accuracy and precision of an instrument are accuracy and precision of an instrument are important in evaluating the reliability and important in evaluating the reliability and usefulness of the data the instrument usefulness of the data the instrument generates. generates.

FTIR

Direct readingDirect reading Simultaneous monitoring of low level Simultaneous monitoring of low level

concentrationsconcentrations Higher efficiency than other IR methodsHigher efficiency than other IR methods QualitativeQualitative QuantitativeQuantitative

FTIR

Michelson interferometer detector utilized Michelson interferometer detector utilized to “observe” entire spectrum at same instantto “observe” entire spectrum at same instant

Light is split between two mirrorsLight is split between two mirrors Reflected light beam split is measured Reflected light beam split is measured Fourier transform is used to plot intensity Fourier transform is used to plot intensity

versus wave number comparing moving and versus wave number comparing moving and stationary mirrorsstationary mirrors

FTIR

Typically used in “extractive mode” as Typically used in “extractive mode” as compared to open-path modecompared to open-path mode Real-time monitoringReal-time monitoring Auto exhaust Auto exhaust Stack gasesStack gases Air pollutionAir pollution

FTIR

Useful becauseUseful because Able to monitor wide variety of Able to monitor wide variety of

compoundscompounds Non-invasive monitoringNon-invasive monitoring Covers large areasCovers large areas

FTIR

Calibration is “up in the air” but Calibration is “up in the air” but calibration cells are being developed.calibration cells are being developed.

Discrepancy between clean air and Discrepancy between clean air and monitored air can be troublesome in field monitored air can be troublesome in field scenariosscenarios

FTIR

References Cited

http://www.ftir.cz/http://www.ftir.cz/ Accessed 05/02/01 Accessed 05/02/01

http://www.nicoletindustrial.com/Antaris/Antaris.http://www.nicoletindustrial.com/Antaris/Antaris.htmlhtml

Accessed 05/02/01 Accessed 05/02/01

NIOSH Manual of Analytical Methods NIOSH Manual of Analytical Methods (NMAM®), 4th ed.(NMAM®), 4th ed.DHHS (NIOSH) Publication 94-113 (August, DHHS (NIOSH) Publication 94-113 (August, 1994),1994),Cassinelli, M.E. & Cassinelli, M.E. & O'Connor, P.F. (pfo1@O'Connor, P.F. (pfo1@cdccdc..govgov)), Eds., Eds.

Bibliography

DiNardi Salvatore R. (1998) DiNardi Salvatore R. (1998) The The Occupational Environment-Its Evaluation Occupational Environment-Its Evaluation and Controland Control, AIHA, Fairfax, Virginia , AIHA, Fairfax, Virginia

Goetsch David L. (1999) Goetsch David L. (1999) Occupational Occupational Safety and Health for Technologists, Safety and Health for Technologists, Engineers, and ManagersEngineers, and Managers, Prentice Hall, , Prentice Hall, Upper Saddle River, New Jersey Upper Saddle River, New Jersey