Real-time determination of volatile organic compounds (VOCs) by ion molecule reaction – mass spectrometry (IMR-MS)

Comprehensive analytical validation studies of a developed ion molecule reaction – mass spectrometer (IMR-MS) were undertaken for the real-time determination of volatile organic compounds (VOCs) in air. The instrument was developed with a focus on promoting chemical ionization (CI) in the reaction chamber by direct sample loading and enhancing maintenance efficiency and reliability of the results. Instrument stability was assessed through a system check and pre-performance check process, and consequently, the instrumental and analytical conditions including the plasma generation, pressure, temperature, and flow rate were successfully optimized. Relevant performance characteristics, such as mass resolution, mass detection range, accuracy, and precision were also investigated by VOC standards composed of benzene, toluene, perfluorotoluene, propylbenzene, and octane. To evaluate whether the performance of the technology is comparable to already accepted techniques, the quantitative results of the IMR-MS were compared with those of a commercial mass spectrometer. This evaluation was successful and suggests the applicability of the technology for spillage accidents of hazardous chemicals and identification of odor-causing substances as well as for real-time gas analysis.</p