DRUG SCREENING IN BIOLOGICAL-FLUIDS - THE NEED FOR A SYSTEMATIC-APPROACH

In this paper the key steps towards drug screening in biological fluid s are considered: (i) sample work up-isolation-concentration: (ii) dif ferentiation-detection; (iii) identification. For (i) solid-phase extr action has very good potential; for (ii) thin-layer chromatography, ga s chromatography and high-performance liquid chromatography, in combin ation with their respective detection modes, each have their particula r advantages and disadvantages; for (iii) extensive computerized data bases are essential. It is emphasized that each step must be approache d and carried out in a systematic way, not only to make sure that all substances of interest can be detected, but also for their correct ide ntification. To this end all analytical procedures and techniques used require extensive validation of their detection and identification pr operties.