Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels

A system for on-line measurements of trace components with concentrations as low as a few pptv has been developed on the basis of proton transfer reactions. Medical applications by means of breath analysis allow the monitoring of metabolic processes in the human body, and examples of food research include investigations of volatile organic compound (VOC) emissions from fruit, coffee and meat. Investigations of VOC emissions from decaying biomatter and on-line monitoring of the diurnal variations of VOCs in ambient air are typical examples of environmental applications.