Source Determination for Indoor Toluene and Xylene Pollution by Portable Time-of-light Mass Spectrometer

Health, risk caused by indoor pollution has aroused increasing concerns, and most of indoor pollutants are regarded as volatile organic compounds (VOCs). In this study, indoor VOC source determination based on real-time monitoring was successfully demonstrated by portable time-of-flight mass spectrometer (P-TOF-MS) while toluene and xylene were used as model compounds. The concentration distribution of toluene and xylene in a 1394 m super(2) room was studied under both contaminated and ventilated conditions. Air samples from 40 sampling sites were analyzed within 1.5 h; the highest concentrations of toluene and xylene were 2633 mu g/m super(3) and 223 mu g/m super(3) when the indoor air was contaminated; however, these concentrations decreased significantly to 113 mu g/m super(3) and 173 mu g/m super(3) after ventilating the room for 24 h. This result indicates P-TOF-MS can be used as a promising technique for indoor (e. g., home, workshop) VOC monitoring as well as its source determination.