Marriott Philip, Aryusuk Kornkanok, Shellie Robert, Ryan Danielle, Krisnangkura Kanit, Schurig Volker, Trapp Oliver
Department of Applied Chemistry, Australian Centre for Research on Separation Science, RMIT University, City Campus, GPO Box 2476V, Melbourne, Vic. 3001, Australia.
J Chromatogr A. 2004 Apr 9;1033(1):135-43. doi: 10.1016/j.chroma.2004.01.035.
Comprehensive two-dimensional gas chromatography (GC x GC) is shown to provide information on dynamic molecular behaviour (interconversion), with the interconversion process occurring on both columns in the coupled-column experiment. The experiment requires suitable adjustment of both experimental conditions and relative dimensions of each of the columns. In this case, a longer column than normally employed in GC x GC allows sufficient retention duration on the second column, which permits the typical plateau-shape recognised for the interconversion process to be observed. The extent of interconversion depends on prevailing temperature, retention time, and the phase type. Polyethylene glycol-based phases were found to result in high interconversion kinetics, although terephthalic acid-terminated polyethylene glycol had a lesser extent of interconversion. Much less interconversion was seen for phenyl-methylpolysiloxane and cyclodextrin phases. This suggests that for the oximes, interconversion largely occurs in the stationary phase. Examples of different extents of interconversion in both dimensions are shown, including peak coalescence on the first column with little interconversion on the second column.
全二维气相色谱（GC×GC）已被证明能够提供有关动态分子行为（相互转化）的信息，在联用柱实验中，相互转化过程在两根柱子上都会发生。该实验需要对实验条件以及每根柱子的相对尺寸进行适当调整。在这种情况下，使用比GC×GC中通常使用的更长的柱子能够在第二根柱子上获得足够的保留时间，从而可以观察到相互转化过程中典型的平台形状。相互转化的程度取决于当前温度、保留时间和固定相类型。发现基于聚乙二醇的固定相具有较高的相互转化动力学，尽管对苯二甲酸封端的聚乙二醇的相互转化程度较小。对于苯基甲基聚硅氧烷和环糊精固定相，相互转化的情况要少得多。这表明对于肟类化合物，相互转化主要发生在固定相中。展示了在两个维度上不同相互转化程度的示例，包括第一根柱子上的峰合并而第二根柱子上几乎没有相互转化的情况。
