Performance evaluation of hand-held ion mobility spectrometer for field screening detection system

Ion mobility spectrometry (IMS) is a vanguard analytical technique that provides analytical information in a simple, rapid and, inexpensive manner. Some advantages of IMS are low detection limits (nanogram), fast analysis time (provides output data in seconds), operation in atmospheric pressure eliminating bulky vacuum systems, can be miniaturization capability along with battery mode operation. In addition, it is comparably less expensive to purchase and operate than other trace detection technologies [1,2]. Because of these, design and construction of Hand-held ion mobility spectrometer having been done for first time in Iran in Materials and Energy Institute of Esfahan, Spectrometry and Microelectronic Devices department. This instrument has the advantages of a simple, rugged system, fast response and fast clear down time. The potential of Hand-held IMS was investigated for explosive detection capabilities. Thermal solid introduction configuration provides fast and easy applied method for direct detection with no additional sample preparation or extraction, rapid cleaning time and without using special kind of sampling filter or wand. The time required for total analysis and readiness for next analysis is less than 20 sec. The wide range of solid matrixes, including nitrate esters, nitroaromatics, nitramines and also liquid and gas samples are determined by Hand-held IMS. The fast analysis time limits degradation of the thermally labile compounds and decreases the peak widths, which results in larger peak intensities and a simultaneous improvement in detection limits. For signal-to-noise ratio equals to 5, the detection limits for instrument for TNT, DNT and RDX were attained 3, 5 and 30 ng/µL respectively. The combination of short analysis time and low detection limits make this instrument a potential candidate for field screening techniques.