Laboratory of Clinical Toxicology, C.H.U. de Liège, B-4000 Sart Tilman, Belgium

In this report, results on the determination of plasma neuroleptics and some investigations into the limits of detection of compounds difficult to identify like buprenorphine, LSD and pancuronium will be presented.

Neuroleptics represent a very heterogenous pharmacological group of drugs (phenothiazines, thioxanthenes, butyrophenones, etc) with a wide range of therapeutic and toxic concentrations (from ng/ml up to µg/ml). They are frequently used in suicide attempts but all existing systematic toxicological analysis procedures are just sensitive enough to find only the most concentrated ones (i.e. chlorpromazine, prothipendyl). More sensitive methods are generally focused on one specific compound like haloperidol or benperidol. Using liquid chromatography coupled with an ion trap mass spectrometry detector, we have developed a method to screen and identify the most relevant compounds in plasma. After a classical screening extraction procedure with Bond Elut Certify™ SPE column, 5 µl of the extract were injected into a C18 HPLC column (Phenomenex™ Jupiter 50 x 2.0 mm i.d.). Separation of neuroleptics was achieved with a mobile phase 2 mM formic acid pH 3.5/acetonitrile (50/50 ; v/v) at 0.5 ml/min. With multiple reactions monitoring (MRM), specific mass transitions allowed the identification of twelve of the most relevant neuroleptics. Limits of detection varied from 0.1 to 1 ng/ml depending on the drug.