2022 Volume 27 Issue 1 Pages 49-62
An MX908 portable mass spectrometer utilizing low-vacuum (high pressure) mass analyzer was evaluated for the detection of chemical warfare agents. The MX908 mass spectrometer accommodates volatile agents like sarin (GB) in the vapor mode and low-volatile agents like VX in the trace mode. We verified that VX could be detected in the trace mode, however a Nomex swab was superior to the original PTFE swab in terms of the alarm limit of VX. For the screening of VX on stainless-steel or plastic surface, we recommend to wet the Nomex swab with 2-propanol (10 μL) prior to wiping the surface or drop 2-propanol (10 μL) on the surface and wipe with the Nomex swab immediately. The optimized wiping methods could detect 100 ng of VX on both of the surfaces. GB was detected at 0.25-0.50 mg/m3 in the vapor mode, which was compatible with a common ion-mobility spectrometry instrument (LCD 3.3). Tabun (GA) was properly detected at 1 mg/m3, however neither MX908 nor LCD 3.3 could discriminate soman (GD) and cyclohexylsarin (GF) at 1 mg/m3. Sulfur mustard (HD) could not be detected at 64 mg/m3. Because significant loss (18-54%) during vapor preparation presumably due to the adsorption on the surface of the sampling bag and the transfer tube was observed, actual sensitivity would be superior to the above-mentioned nominal values.
