SDEP measure segment matching


Gas chromatography, because of its high resolution, is widely used in environmental analysis to determine a wide range of pollutants. This technique is applied to both volatile and, after a derivatization step, to nonvolatile analytes. Environmental samples are usually quite complex because of the different pollutants which may be present. Multidimensional chromatography (MDGC) or GC-GC coupling would therefore be expected to be widely applied in environmental analysis. Despite its many advantages, however, a major drawback with MDGC is that, in principle, many heart-cuts from the first column should be subjected to a second separation. In other words, the method can become extremely time consuming. One remedy is to combine several heart-cuts and analyse these in one second run. However, the risk of co-elution then markedly increases and this is particularly dangerous when detection with no identification power is used. This is what happens, for example, with chlorinated analytes, for which electron-capture detection is the most widely used, due to its high sensitivity (5).  [c.336]


Molecular modelling Principles and applications (2001) -- [ c.540 ]