Modern chromatographic procedures in systematic toxicological analysis

The fact that the toxicologist in systematic toxicological analysis never knows what he is looking at but has to take into account a vast number of toxicologically relevant substances makes this field a very difficult, yet challenging task. Because of the strong qualitative emphasis gas and thin-layer chromatography are at present the techniques of choice, and can be used with other relevant techniques such as spray reactions on the plate, UV spectrophotometry and mass spectrometry. However, as a single chromatographic technique will never provide unequivocal identification, the techniques have to be used side by side, so that the final identification matches the results from all the techniques applied. This approach requires that the advantages and disadvantages of each technique be well known so that a combination of techniques can be chosen that provides the optimum identification power. After the unknown substance(s) have been analysed by a number of techniques and their particular behaviour in these techniques has been established, these findings are then matched against a data bank containing the behaviour of reference substances. This data bank should be as large as possible. Moreover, the search process used with the data bank must take into account the identification power of each individual technique, otherwise a well balanced “yes-no” decision about the presence or absence of a given substance is impossibl