PORTABLE HAND-HELD GAS-CHROMATOGRAPHY ION MOBILITY SPECTROMETRY DEVICE

The concept of a portable gas chromatography/ion mobility spectrometry (GC/IMS) device is introduced. The potential of the GC/IMS unit is investigated for the separation and characterization of vapor mixtures of various chemical classes. Parameters such as internal cell pressure, GC column flow rate, and column temperature were varied to determine the effects on speed and resolution for separating and characterizing mixtures. It was generally found that by reducing both the internal IMS cell pressure and the isothermal GC column temperature, the peak widths, retention times, and peak overlap could be varied for different classes of analytes. The GC/IMS system shows versatility in the various compound classes that can conveniently be analyzed by a hand-portable version. Mixtures included phosphonates, phosphates, alkyl ketones, and chlorophenols with total separation times in the 7-s to 2-min time range. Positive or negative ion polarities in IMS were used depending upon the functional group.