Real-time monitoring traces of SF6 in near-source ambient air by ion mobility spectrometry

The leakage of sulphur hexafluoride (SF6) gas threats the global climate changes and personnel safety. Monitoring the concentration of SF6 in its application places is an industry regulation. In this study, ion mobility spectrometry (IMS) was developed for fast monitoring traces of SF6 in near-source ambient air. Due to the water is an important part of the natural air and affects most atmospheric measurements, the operating parameters of IMS monitoring SF6 were optimised for quantitative analysis of SF6 at different relative humidity (RH). It is discovered two main product ions SF6- and SOF4- by IMS at different RH. The calibration curves of SF6 were investigated by its relationship with the peak intensity of SOF4- for real application. The time resolution of the measurement was obtained less than 1 s and the limit of detection (LOD) achieved 0.16-0.68 ppm with a data averaging of 30 times. At last, the simulated application of monitoring SF6 leakage was tested in the fume hood of our lab. The results showed a great potential application prospect of IMS in monitoring SF6 in the ambient air of its application places