A capillary gas-liquid chromatographic method for the assay of the neuroleptic drug zotepine in human serum or plasma.

A capillary gas-liquid chromatographic method suitable for the assay of the atypical neuroleptic drug zotepine in human serum or plasma was developed. A liquid-liquid extraction with three subsequent extraction steps was applied for sample preparation. The minimum detectable concentration was 1.0 ng ml-1. The within-day relative standard deviation (RSD) (n = 6) was 5.3% at 5 ng ml-1, 3.6% at 10 ng ml-1 and 6.1% at 100 ng ml-1. The day-to-day RSD (n = 6) was 9.3% at 10 ng ml-1 and 5.1% at 100 ng ml-1. Steady-state serum levels of four schizophrenic patients were measured.