Multidimensional fast gas chromatography on basis of flow-field thermal gradient gas chromatography

点击翻译按钮获取中文摘要

The project within the framework of the program New devices for research is aimed at the development of a new type of fast multidimensional gas chromatography. Currently the measurements are made with complex measurement systems whose data are and difficult to interpret. This prevents a broad adoption of this technology in basic research. The new gas chromatographic method will be fast and easy to use. In different areas of basic research a more differentiated look on chemical complexity will be established. Furthermore, dynamic processes can be observed by the fast cycling measurement system. New research over extensive sample numbers becomes possible. In classical gas chromatography co-elution is frequent, especially in fast and low resolution measurements. Two dimensional gas chromatography suppresses co-elution with two successive columns and two different separation mechanisms. Two different methods are established. With heart-cutting GC selected time intervals from the first dimension separation are cut to the second dimension column. In comprehensive GC, or GCxGC, the whole first dimension separation is modulated in very short time intervals and separated on a short and fast second column. The proposal describes an alternative approach which has some advantages compared to the present state-of-the-art. It is based on a new basic technology, the flow-field thermal gradient gas chromatography. This separation method yields high resolution in short cycles even below one minute. The thermal gradient focuses the signals, the modified chromatographic transport lowers elution temperatures substantially. Therefore the application range of GC is expanded. The conceptual and technical simplicity makes FF-TG-GC an ideal module for multidimensional gas chromatographic set-ups. The basic idea is the coupling of two FF-TG-GC systems. The sample mixtures are separated on a short first column in an intermittent way. This has become possible with the very fast cooling flow-field principle. By valveless switching (e.g. a Deans switch) the eluates are directed to the second column. Here, complete temperature and gradient programmed separation on an orthogonal column takes place in the thermal gradient mode.