CARBON SORBENTS AND THEIR UTILIZATION FOR THE PRECONCENTRATION OF ORGANIC POLLUTANTS IN ENVIRONMENTAL-SAMPLES

This review deals with carbon sorbents and their utilisation to trace analysis of organic pollutants in environmental samples. The first sec tions are devoted to the general characteristics of various kinds of c arbon sorbents, carbon formation, the structure of carbon, their class ification and characterisation (activated charcoal, graphitized carbon black, carbon molecular sieves and porous carbon). Information is giv en on the development of carbonaceous adsorbents, their characteristic s and properties, development of various preconcentration techniques, off-line or on-line combination with the analytical measuring system ( GC and HPLC), and the application of carbon sorbents to the enrichment of analytes is evaluated. The main use of carbon materials as a preco ncentration/preseparation step has been in the sampling and trapping o f volatile organic compounds (VOCs) froth air and water matrices. An o ther field of application is the trapping of semi-volatile and non-vol atile -compounds and/or their separation into subclasses. According to the characteristics of the sampled components, carbon sorbents have b een utilised in single-bed or multi-bed arrangement (combination of va rious carbon sorbents or combinations of carbon sorbents with other no n-carbonaceous materials) to achieve quantitative trapping of trace co mponents from environmental samples, followed by their desorption for subsequent identification and quantitation. Various achievements and p roblems, particularly in multicomponent-mixture analysis, are discusse d. The physico-chemical properties of recently developed carbon adsorb ents are superior compared to those of the ''traditional'' sorbent mat erials. Over the recent years much attention has been paid to the appl ication of carbon sorbents for the on-site automated analysis and moni toring of trace pollutants.