Rapid determination of complex mixtures by dual-column gas chromatography with a novel stationary phase combination and spectrometric detection
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- 作者：Gordon R. Lambertus ; Jeffrey A. Crank ; Megan E. McGuigan ; Shai Kendler ; Daniel W. Armstrong ; Richard D. Sacks
- 关键词：Ionic liquids ; Gas chromatography ; Tunable selectivity ; Differential mobility spectrometry ; Modeling
- 刊名：Journal of Chromatography A
- 出版年：2006
- 出版时间：1 December 2006
- 年：2006
- 卷：1135
- 期：2
- 页码：230-240
- 全文大小：1155 K
文摘
Fast GC separations of a broad range of analytes are demonstrated using a capillary column coated with a novel immobilized ionic liquid (IIL) stationary phase. Both completely cross-linked and partially cross-linked columns were evaluated, yielding 1600 and 2000 theoretical plates per meter, respectively. Enhanced separation is demonstrated using a dual-column ensemble comprised of an IIL column, a commercially coated Rtx-1 column, and a pneumatic valve connecting the inlet to the junction point between the two columns. Enhanced separation of 20 components, with two sets of co-eluting peaks is shown in 150 s, while sacrificing only a length of time equivalent to the sum of the stop flow pulses, or about 15.5 s. A novel application of a band trajectory model that shows band position as a function of analysis time as analytes move through the column ensemble is employed to determine pulse application times. The model predicts component retention times within a few seconds. Another method of selectivity enhancement of the IIL stationary phase-coated columns is demonstrated using a differential mobility spectrometer (DMS) that provides a second dimension separation based on ion mobility in a high-frequency electrical field. The DMS is able to separate all but one set of co-eluting components from the IIL column. The separation of 13 components found in the headspace above U.S. currency is demonstrated using the IIL column in a dual-column ensemble as well as with the DMS.