[Yeretzian2000a] "Time-resolved headspace analysis by proton-transfer-reaction mass-spectrometry",
ACS Symposium Series
, vol. 763: ACS Publications, pp. 58–72, 2000.
A recently developed technique, Proton-Transfer-Reaction Mass-Spectrometry (PTR-MS), is reviewed based on applications on coffee. PTR-MS is a sensitive and fast method for on-line trace gas analysis. It consists of a specially designed chemical ionization cell, where headspace gas is continuously introduced and volatile organic compounds ionized by proton-transfer from H3O+. Protonated compounds are then mass analyzed in a quadrupole mass filter. First a description of the method will be given, with emphasis on the ionization mechanism. We then discuss a series of experiments that allow mass spectral intensities to be related to chemical compounds. Finally, two applications on coffee are discussed.