论文信息 - Real-time monitoring of chlorinated aliphatic compounds in air using ion mobility spectrometry with photoemissive electron sources

Real-time monitoring of chlorinated aliphatic compounds in air using ion mobility spectrometry with photoemissive electron sources

Ion mobility spectrometry with a photoemissive electron source is a promising approach for monitoring vapors of highly electronegative species such as chlorinated solvents and explosives. Electrons are generated over well-defined intervals by ultraviolet irradiation of a metal plate or metal-coated window by either a flashlamp or a pulsed laser beam, so no gating of the drift process is required. The negative ion mobility spectrum of air exhibits features predominately due to clusters of oxygen anion with water molecules. These species readily transfer electrons to chlorinated aliphatic compounds that undergo dissociative electron attachment to generate chloride ions. The ion mobility spectra change in a predictable fashion, permitting real-time detection of chlorinated species at low ppmV concentration. In this presentation we shall describe our methodology, display the response characteristics of our instrument, and summarize our investigations of the relevant ion-molecule reactions.

Christopher J. Walls | Orven F. Swenson | Gregory D. Gillispie | O. Swenson | G. Gillispie

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