Analytical and Testing Center, Sichuan University, Chengdu 610064, P.R. China.
College of Chemical Engineering, Sichuan University, Chengdu 610065, P.R. China.
Sci Rep. 2017 Mar 13;7:44051. doi: 10.1038/srep44051.
This work demonstrates the application of a novel microwave induced plasma ionization (MIPI) source to ion mobility spectrometry (IMS). The MIPI source, called Surfatron, is composed of a copper cavity and a hollow quartz discharge tube. The ion mobility spectrum of synthetics air has a main peak with reduced mobility of 2.14 cmVs for positive ion mode and 2.29 cmVs for negative ion mode. The relative standard deviations (RSD) are 0.7% and 1.2% for positive and negative ion mode, respectively. The total ion current measured was more than 3.5 nA, which is much higher than that of the conventional Ni source. This indicates that a better signal-to-noise ratio (SNR) can be acquired from the MIPI source. The SNR was 110 in the analysis of 500 pptv methyl tert-butyl ether (MTBE), resulting in the limit of detection (SNR = 3) of 14 pptv. The linear range covers close to 2.5 orders of magnitude in the detection of triethylamine with a concentration range from 500 pptv to 80 ppbv. Finally, this new MIPI-IMS was used to detect some volatile organic compounds, which demonstrated that the MIPI-IMS has great potential in monitoring pollutants in air.
本工作展示了一种新型微波诱导等离子体电离（MIPI）源在离子迁移谱（IMS）中的应用。MIPI 源称为 Surfatron，由铜腔和空心石英放电管组成。正离子模式下的合成空气的离子迁移谱具有一个主峰，其迁移率降低为 2.14 cmVs，负离子模式下的迁移率降低为 2.29 cmVs。正离子模式和负离子模式的相对标准偏差（RSD）分别为 0.7%和 1.2%。测量得到的总离子电流超过 3.5 nA，远高于传统的 Ni 源。这表明可以从 MIPI 源获得更好的信噪比（SNR）。在分析 500 pptv 甲基叔丁基醚（MTBE）时，SNR 为 110，导致检测限（SNR = 3）为 14 pptv。在检测三乙胺时，线性范围接近 2.5 个数量级，浓度范围为 500 pptv 至 80 ppbv。最后，将这种新型 MIPI-IMS 用于检测一些挥发性有机化合物，证明了 MIPI-IMS 在监测空气中污染物方面具有巨大的潜力。
