Proton-Transfer-Reaction–Mass Spectrometry

The mission of the agro-food industry is to guarantee food safety and, at the same time, improve perceived food quality and fulfill consumer expectations. One of the chief quality traits for the agro-food industry is the development of volatile organic compounds (VOCs), associated with the shelf life and taste quality of food products. Proton-transfer-reaction–mass spectrometry coupled with a time-of-flight mass analyzer gives the possibility of detecting and quantifying VOCs in a direct, simultaneous, and real-time approach at very low levels with both high mass and time resolution. External mass-scale calibration is performed before data acquisition for spectra alignment and for facilitating the online monitoring of ongoing experiment. Since proton-transfer reaction-mass spectrometry (PTR-MS) belongs to the class of Direct injection mass spectrometric techniques, its main capability is to sample and analyze gas samples continuously. For this reason, PTR-MS, from the very beginning, was mostly applied in the ambient and environmental studies of air pollutants.