Scientists develop new method for airborne chemical warfare agent detection
Yasuo Seto, a scientist with Japan's National Institute of Police Science, and his research team developed a method that employs counter-flow introduction atmospheric pressure chemical ionization mass spectrometry. The researchers examined four highly toxic chemical agents using MS, including mustard gas, Lewisite 1, sarin and tabun.
Seto and his team conducted soft ionization using corona discharge to form reactant ions that were then sent against the airflow using an electric field. This process eliminated interfering molecules such as nitrogen oxide and ozone and allowed for the efficient ionization of the target chemical agents.
The researchers also developed quadrupole MS and ion trap tandem MS devices that were able to move on the floor of the building. They used optimized combinations of parent and daughter ion pairs to allow for real-time detection of the chemical agents.
The authors of the study found that the MS detection method was able to identify mustard gas, tabun and sarin in positive ion mode. Using negative ion mode, they were able to detect Lewisite 1. The agents were detected at limit of detection values as low as one microgram per cubic meter.
The study represented the first demonstration of specific and sensitive real-time detection of positively and negatively ionizable chemical weapon agents using MS instruments. The findings were published in the journal Analytical Chemistry.