Multidimensional Chromatography in Environmental Analysis

Multidimensional chromatography has important applications in environmental analysis. Environmental samples may be very complex, and the fact that the range of polarity of the components is very wide, and that there are a good many isomers or congeners with similar or identical retention characteristics, does not allow their separation by using just one chromatographic method. 

The main aims in environmental analysis are sensitivity (due to the low concentration of microcontaminants to be determined), selectivity (due to the complexity of the sample) and automation of analysis (to increase the throughput in control analysis). These three aims are achieved by multidimensional chromatography sensitivity is enhanced by large-volume injection techniques combined with peak compression, selectivity is obviously enhanced if one uses two separations with different selectivi-ties instead of one, while on-line techniques reduce the number of manual operations in the analytical procedure. 

In target-compound analysis, a particular compound, usually present in a complex matrix and at trace levels, needs to be quantified. Here, selectivity and 

Soil extracts are usually very complex. In water samples, humic and fulvic acids make analysis difficult, especially when polar substances are to be determined. Multidimensional chromatography can also make a significant contribution here to this type of analysis. 

The use of multidimensional chromatography in environmental analysis has been reviewed in the literature (1-6). Of the multidimensional systems described in previous chapters, GC-GC liquid chromatography LC-LC and LC-GC, whose applications to environmental analysis will be detailed in this chapter, are the ones most often used in environmental analysis. 

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