Article in ACS’ Analytical Chemistry journal: Discovery of a new dimension in selectivity for PTR-MS
We have already successfully demonstrated the ability of PTR-MS to detect common threat agents such as CWAs, TICs and Explosives in earlier studies. Using high-resolution IONICON PTR-TOFMS series instruments an unambiguous identification of most known substances has already been proven.
A new study shows that another potentially useful procedure for the elimination of false positives with regard to the detection of TNT using PTR-MS technology was found:
For protonated TNT, rather than decreasing signal intensity with increasing E/N (the ratio of the electric field strength E to buffer gas number density N in the drift tube), which is the more usual sensitivity pattern observed in PTR-MS studies, an anomalous behavior is observed, whereby the signal intensity initially rises with increasing E/N.
This dependence provides an easily measurable signature that can be used to provide a rapid highly selective analytical procedure to minimize false positives for the detection of TNT. This has major implications for Homeland Security and, in addition, has the potential of making instrumentation cost-effective for use in security areas.
Link to the ACS’ Analytical Chemistry journal article