Proton Transfer Reaction-Mass Spectrometry for On-line Analysis of Trace Volatile Organic Compounds

Proton transfer reaction mass spectrometry (FM-MS) is a technique developed almost exclusively for the detection of volatile organic compounds (VOCs). By using H(3)O(+) as the reacting agent, proton transfer reaction with proton acceptor VOCs can be obtained. Most of the common inorganic constituents of air possess proton affinities lower than that of H(2)O and, therefore, can not react with H(3)O(+). Consequently, PTR-MS can be used to detect trace VOCs in the environment at atmospheric conditions without interference from air. Compared to gas chromatography-mass spectrometry (GC-MS), PTR-MS has some significant advantages such as fast response time, high sensitivity, absolute measurements, and simple preparation for samples, thus making it the preferred method for VOC detection. In this review, we briefly introduced the principles and apparatus of PTR-MS. Moreover, we also discussed the development of PTR-MS, with special focus on domestic PTR-MS, and gave some typical example applications of PTR-MS in the fields of environmental science, food, and medical diagnostics.