METHOD AND APPARATUS FOR IMPROVING THE SPECIFICITY OF AN IONMOBILITY SPECTROMETER UTILIZING SULFUR DIOXIDE DOPANT CHEMISTRY

摘要

An improved ion mobility spectrometer (IMS) and method for operating the same which enables analysis of a specific acid gas analyte in a mixture of such gases when air is used as the carrier gas and the drift gas in the IMS. A controlled concentration of sulfur dioxide dopant is added to the air carrier gas stream prior to application of the carrier gas stream. In the IMS, the drift times of the ions generated from the doped air carrier gas differ from the drift times of the ions generated from the acid gas analyte, thereby enabling identification and quantification of the analyte.