Abstract
Chemical Ionization Mass Spectrometry (CI-MS) techniques are appropriate for the determination of volatile organic compound (VOC) emissions from terrestrial vegetation, provided that these compounds have unique analytical ions. In practice, however, many plant volatiles, and mainly those emitted by the isoprenoid and lipoxygenase biochemical pathways, have CI product ions at overlapping m/z values. In this paper, Selected Ion Flow Tube (SIFT) gas phase ion chemistry studies of several series of plant volatile classes using H3O+ and NO+ reagent ions, which have provided the kinetic and mechanistic parameters required for plant volatile quantification by SIFT-MS, are reviewed. The available information has been gathered into tables which allow the reader to decide which analytical ions are best monitored to quantify specific biogenic VOC emissions by SIFT-MS in the presence of interfering compounds. Some typical examples of interferences and how they can be resolved are subsequently given. The reviewed ion chemistry, obtained under SIFT conditions, is also relevant to the analysis of biogenic VOC emissions by Proton Transfer Reaction - Mass Spectrometry (PTR-MS).
Keywords: Green leaf volatiles, isoprenoids, plant volatiles, selected ion flow tube mass spectrometry, SIFT-MS, proton transfer reaction mass spectrometry, PTR-MS.
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