Solid-phase extraction procedures in systematic toxicological analysis

In systematic toxicological analysis (STA) the substance(s) present is (are) not known at the start of the analysis. in such an undirected search the extraction procedure cannot be directed to a given substance but must be a general procedure where a compromise must be reached in that the substances of interest are isolated at a yield as high as possible and the interfering substances from the biological material are removed. Wen using solid-phase extraction (SPE) it is desirable to have procedures using just one column. An overview of screening procedures using diatomaceous earth, polystyrene-divinylbenzene copolymer and mixed-mode bonded silica as column material in SPE is given. The latter type of sorbent is most popular at the moment and the critical steps in the procedure are outlined in more detail. Recent developments of SPE disks look very promising for STA. (C) 1998 Elsevier Science B.V. All rights reserved.