Electrochemical detection of benperidol in serum for drug monitoring in humans.

A high-pressure liquid chromatographic (HPLC) method for the serum assay of benperidol is described. One ml of serum is required for a single estimation. The method involves a simple and rapid extraction step (BondElut columns), HPLC separation (C8 10-mu column), and electrochemical detection (+0.65 V). Haloperidol is used as internal standard. On the basis of this procedure, recovery (93-97%) and reproducibility (intra-assay and inter-assay coefficients of variation less than 9%) are satisfactory. The detection limit is 0.2 ng/ml of serum. After therapeutic doses, trough serum levels ranged from 3.8 to 12 ng/ml in five patients.