Chemical vapor identification using field-based attenuated total reflectance Fourier transform infrared detection and solid phase microextraction

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) technology is used to identify chemicals in a liquid or solid phase but not in a vapor phase. This research identified vapor phase chemicals using a field-portable ATR-FTIR spectrometer combined with a solid phase microextraction (SPME) film. Two nerve agent simulants, diisopropyl methylphosphonate (DIMP) and dimethyl methylphosphonate (DMMP), and three polycarbosiloxane polymers were evaluated using a TravelIR(TM) ATR-FTIR instrument. A SPME film was adhered to the TravelIR(TM) sampling interface to extract and concentrate vapors to be identified by the TravelIR(TM). The lowest air concentration identified was 50 ppb DIMP and 250 ppb DMMP. A remote sampling technique where SPME films were exposed to vapors and then transferred to the TravelIR(TM) was only able to identify DMMP down to 10 ppm. This research demonstrates it is feasible to use ATR-FTIR to detect vapor phase chemicals when combined with SPME film concentration techniques.