Real-time and on-line monitoring volatile organic compounds（VOCs） are valuable for real-time evalua- ting air quality and monitoring the key source of pollution. A self-developed proton transfer reaction-mass spectr...Real-time and on-line monitoring volatile organic compounds（VOCs） are valuable for real-time evalua- ting air quality and monitoring the key source of pollution. A self-developed proton transfer reaction-mass spectro- meter（PTR-MS） was constructed and applied to on-line monitoring trace VOCs in ambient air in Hefei, China. With the help of a self-developed catalytic converter, the background signal of the instrument was detected and the stability of the instrument was evaluated. The relative standard deviation of signal at m/z 21 was only 0.74% and the detection limit of PTR-MS was 97 part per trillion（97x 10-12, volume ratio）. As a case of the air monitoring in Hefei, the am- bient air at Dongpu reservoir spot was on-line monitored for 13 d with our self-developed PTR-MS. Meanwhile, a solid-phase micro-extraction（SPME） technique coupled to gas chromatography-mass spectrometry/mass spectrometry （GC-MS/MS） was also used for the off-line detection of the air. The results show that our self-developed PTR-MS can be used for the on-line and long-term monitoring of VOCs in air at part per trillion level, and the change trend of VOCs concentration monitored with PTR-MS was consistent with that detected with the conventional SPME-GC-MS. This self-developed PTR-MS can fully satisfy the requirements of air quality monitoring and real-time monitoring of the key pollution sources.展开更多
基金Supported by the National Natural Science Foundation of China（Nos.21477132, 21577145）, the National Key Technology Research and Development Program of China（No.2015BAI01B04）, the National Key Research Program of China （No.2016YFC0200200）, the Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology of China（No.2014FXCX007） and the Functional Development Program of Instrument and Equipment in Chinese Academy of Sciences.
文摘Real-time and on-line monitoring volatile organic compounds（VOCs） are valuable for real-time evalua- ting air quality and monitoring the key source of pollution. A self-developed proton transfer reaction-mass spectro- meter（PTR-MS） was constructed and applied to on-line monitoring trace VOCs in ambient air in Hefei, China. With the help of a self-developed catalytic converter, the background signal of the instrument was detected and the stability of the instrument was evaluated. The relative standard deviation of signal at m/z 21 was only 0.74% and the detection limit of PTR-MS was 97 part per trillion（97x 10-12, volume ratio）. As a case of the air monitoring in Hefei, the am- bient air at Dongpu reservoir spot was on-line monitored for 13 d with our self-developed PTR-MS. Meanwhile, a solid-phase micro-extraction（SPME） technique coupled to gas chromatography-mass spectrometry/mass spectrometry （GC-MS/MS） was also used for the off-line detection of the air. The results show that our self-developed PTR-MS can be used for the on-line and long-term monitoring of VOCs in air at part per trillion level, and the change trend of VOCs concentration monitored with PTR-MS was consistent with that detected with the conventional SPME-GC-MS. This self-developed PTR-MS can fully satisfy the requirements of air quality monitoring and real-time monitoring of the key pollution sources.
