Design, development, and performance of a fieldable chemical and biological agent detector

A detector based on an ion trap mass spectrometer is being developed for the U.S. Army for battlefield detection of both chemical and biological weapons (CW/BW). The primary operating modes for this instrument are selected via a multiport valve that directs the sample flow into the detector from one of several inlets designed to admit volatilized chemical agents, liquid chemical agents on the ground, or aerosolized particles that may contain a biological agent. The instrument is designed to be highly sensitive in order to minimize false negatives; it therefore makes use of an ion trap mass spectrometer as the detector. Significant effort is also being placed on efficient sample transmission using deactivated sample transport lines and in situ derivatization of the less volatile BW biomarkers. In addition to being sensitive, the instrument must be highly selective in order to minimize false positives. Particle-size discrimination, chemical ionization, and MS/MS experiments combine to provide a high degree of chemical selectivity. Fatty-acid standards, gamma-killed bacteria, dimethylmethylphosphonate, and methyl salicylate have been analyzed with the use of a preproduction instrument to demonstrate the primary operating modes of this instrument. © 2000 John Wiley & Sons, Inc. Field Analyt Chem Technol 4: 93–110, 2000