High-performance liquid chromatographic method with diode array detection to identify and quantify atypical antipsychotics and haloperidol in plasma after overdose.

For toxicological purposes, an HPLC assay was developed for the simultaneous determination of haloperidol and atypical antipsychotics (risperidone, 9-hydroxyrisperidone, olanzapine, clozapine) in human plasma. After a double-step liquid-liquid extraction, compounds were separated on a C(8) column eluted with a gradient of acetonitrile and phosphate buffer 50 mM pH 3.8. A sequential ultraviolet detection was used (260, 280 and 240 nm). Calibration curves were linear in the range 10-1000 ng/ml. The limits of quantification were 5 ng/ml for all drugs. Average accuracy at four concentrations ranged from 93 to 109%. Both inter- and intra-day variation coefficients were lower than 11% for all drugs. This simple and rapid method (run time<15 min) is currently used for poison management.