Rapid preseparation of interferences for ion mobility spectrometry.

Two new approaches to reduce false positive interferences commonly observed with explosives and drugs detection in the field were reported for ion mobility spectrometry (IMS). One of the approaches involved the rapid preseparation of potential interferences prior to detection by IMS. Firstly, it was found that the introduction of a short column packed with adsorption packing material before an IMS could help to reduce the false positive rates. Secondly, the retention time at which the most intense response occurred over the analysis time period could be utilized to separate false positive responses from target analytes with the same drift times. Rapid preseparation of potential interferences provided a greater degree of confidence for the detection (in less than 30s) of drugs, explosives and chemical warfare agents (CWAs). Detection limits as low as 10 pg of TNT with a sensitivity of 12 A g(-1) were reported. Successful development of this technique may lead to the construction of a simple interface fitted with a short column of adsorption packing material to enhance either initial separation or to hold-back interferences mixed with explosive and drug responses in the field.