REAL-TIME DETECTION OF PARTS-PER-TRILLION LEVELS OF CHEMICAL WARFARE AGENTS IN AMBIENT AIR USING ATMOSPHERIC-PRESSURE IONIZATION TANDEM QUADRUPOLE MASS-SPECTROMETRY

An atmospheric pressure ionization tandem quadrupole mass spectrometer system was used to detect, in real time, low levels of chemical warfare agents GB and VX in air. The system exhibits detection limits of 7.2 ppt (parts per trillion) for GB and 6 ppt for VX with a response time of 15 s, using a single reaction monitoring scheme. In order to increase the specificity of detection, two parent-to-daughter transitions can be monitored. However, when such a scheme is utilized, the detection limit for GB is 14.1 ppt and that for VX is 100 ppt.