Open AccessExternal Second Gate-Fourier Transform Ion Mobility Spectrometry.
Author(s) -
Edward E. Tarver
Publication year - 2005
Language(s) - English
Resource type - Reports
DOI - 10.2172/920775
Subject(s) - ion mobility spectrometry , signal (programming language) , explosive material , duty cycle , sensitivity (control systems) , resolution (logic) , fourier transform , mass spectrometry , ion , chemistry , analytical chemistry (journal) , computer science , engineering , physics , electronic engineering , chromatography , electrical engineering , voltage , organic chemistry , quantum mechanics , artificial intelligence , programming language
Ion mobility spectrometry (IMS) is recognized as one of the most sensitive and versatile techniques for the detection of trace levels of organic vapors. IMS is widely used for detecting contraband narcotics, explosives, toxic industrial compounds and chemical warfare agents. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention treaty verification as well as humanitarian de-mining efforts has mandated that equal importance be placed on the analysis time as well as the quality of the analytical data. (1) IMS is unrivaled when both speed of response and sensitivity has to be considered. (2) With conventional (signal averaging) IMS systems the number of available ions contributing to the measured signal to less than 1%. Furthermore, the signal averaging process incorporates scan-to-scan variations decreasing resolution. With external second gate Fourier Transform ion mobility spectrometry (FT-IMS), the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters to increase the spectral resolution. The FT-IMS entrance gate operates with a 50% duty cycle and so affords a 7 to 10-fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system