Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
J Chromatogr A. 2013 Jan 11;1272:126-31. doi: 10.1016/j.chroma.2012.11.063. Epub 2012 Dec 1.
In this study, packed column supercritical fluid chromatography (SFC) was directly coupled to a continuous corona discharge (CD) ion mobility spectrometer (IMS) with several modifications. The main advantage of the developed detector is its capability to introduce full column effluent up to 2000 mL min(-1) CO(2) gas directly into the IMS cell relative to 40 mL min(-1) CO(2) gas as a maximum tolerance, reported for the previous IMS detectors. This achievement was made possible because of using corona discharge instead of (63)Ni as an ionization source and locating the inlet and outlet of the CO(2) gas in the counter electrode of the CD in opposite direction. In addition, a heated interface was placed between back pressure regulator (BPR) and the IMS cell to heat the output of the BPR for introducing sample as the gas phase into the IMS cell. Furthermore, a make-up methanol flow was introduced between the column outlet and BPR to provide a more uniform flow through the BPR and also to prevent freezing and deposition of the analytes in the BPR. The performance of the SFC-CD-IMS was evaluated by analysis of testosterone, medroxyprogesterone, caffeine, and theophylline as test compounds and figures of merit for these compounds have been calculated.
在这项研究中,填充柱超临界流体色谱(SFC)直接与连续电晕放电(CD)离子迁移谱仪(IMS)耦合,进行了一些改进。该开发的检测器的主要优点是它能够将整个柱流出物直接引入 IMS 池,流速高达 2000 mL min(-1)CO(2)气体,而相对于之前的 IMS 检测器报告的最大耐受流速为 40 mL min(-1)CO(2)气体。这一成就的实现是因为使用电晕放电代替(63)Ni 作为电离源,并将 CO(2)气体的入口和出口定位在 CD 的对电极中,方向相反。此外,在背压调节器(BPR)和 IMS 池之间放置了一个加热接口,用于加热 BPR 的输出,将样品作为气相引入 IMS 池。此外,在柱出口和 BPR 之间引入了甲醇补流,以提供更均匀的通过 BPR 的流量,并防止 BPR 中分析物的冻结和沉积。通过分析睾酮、甲羟孕酮、咖啡因和茶碱作为测试化合物来评估 SFC-CD-IMS 的性能,并计算了这些化合物的评价指标。