Hyphenated liquid chromatographic techniques in forensic toxicology

The prerequisite of applicability of hyphenated methods in forensic analysi s is the achievement of a stage of "final maturity". In the field of liquid chromatography, HPLC coupled with diode array detection (DAD) seems to ful fill this criterion, whilst the combination with atmospheric pressure ioniz ation mass spectrometry (HPLC-API-MS) is still in a development stage. HPLC -DAD is broadly used as identification tool in forensic and in emergency to xicology. Two main approaches were observed; development of retention index scales for intra-laboratory exchange of data and establishing of databases only for intra-laboratory use. Using these approaches, several databases w ere established for toxicological relevant substances (illicit and therapeu tic drugs and their metabolites, environmental poisons etc.) in biological fluids. Also, complete HPLC-DAD identification systems are commercially ava ilable. Further possibility of progress depends on the on-line combination ("triple hyphenation") with other detection methods, preferably API-MS. HPL C-API-MS, both in electrospray (ESI) and atmospheric pressure chemical ioni zation (APCI) options, underwent dramatic development in the last decade an d is reaching its final shape. The method was broadly applied for various g roups of toxicologically relevant substances, a lot of them unaccessible fo r other techniques, including GC-MS. Particularly important was application of HPLC-API-MS for detection and quantitation of active, polar metabolites of various drugs and for analysis of macromolecules. APCI seems to be more useful for analysis of less polar compounds, whereas ESI is particularly v aluable for determination of polar, large molecules (e.g., toxic peptides, polar metabolites etc.) Up to now, HPLC-API-MS has been mainly applied for dedicated analyses, but the introduction of APCI or ESI in systematic toxic ological screening may be expected in the near future. (C) 1999 Elsevier Sc ience B.V. All nights reserved.