Chemical agent identification by field-based attenuated total reflectance infrared detection and solid-phase microextraction.
Attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy is used to identify liquid and solid-phase chemicals. This research examines the feasibility of identifying vapor-phase chemicals using a field-portable ATR-FT-IR spectrometer (TravelIR) combined with solid-phase microextraction (SPME). Two nerve agent simulants, diisopropyl methylphosphonate (DIMP) and di-methyl methylphosphonate (DMMP), and three sorbent polymers were evaluated. Each polymer was deposited as a thin film on the instrument's sampling interface to partition and concentrate the simulants from air samples prepared in Tedlar bags. The lowest vapor concentrations identified were 50 ppb (v/v) (DIMP) and 250 ppb (v/v) (DMMP). The ATR-FT-IR instrument demonstrated a linear response at concentrations of 1 ppm (v/v) and below. Increasing the sample exposure time, the sample air velocity, and the film thickness was demonstrated to increase the amount of analyte extracted from the air sample. This research demonstrates that it is feasible to use a portable ATR-FT-IR spectrometer with SPME sampling to detect and identify vapor-phase chemicals.
Bryant
Chet K
CK
Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814-4799, USA. Chet.Bryant@wpafb.af.mil
LaPuma
Peter T
PT
Hook
Gary L
GL
Houser
Eric J
EJ
D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry; D052617:Solid Phase Microextraction / Q000379:methods*; D013055:Spectrophotometry, Infrared / Q000379:methods*; D013997:Time Factors
D011108:Polymers