ArticlesTherapeutic Drug Monitoring of Haloperidol, Perphenazine, and Zuclopenthixol in Serum by a Fully Automated Sequential Solid Phase Extraction Followed by High-Performance Liquid ChromatographyAngelo, Helle R.; Petersen, AndreasAuthor Information Department of Clinical Biochemistry, Bispebjerg Hospital, Copenhagen, Denmark Received February 18, 2000; accepted November 16, 2000. Address correspondence and reprint requests to Helle Angelo, Ph.D., Department of Clinical Biochemistry, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark; E-mail: [email protected] Therapeutic Drug Monitoring: April 2001 - Volume 23 - Issue 2 - p 157-162 Buy Abstract In Denmark, haloperidol, perphenazine, and zuclopenthixol are among the most frequently requested antipsychotics for therapeutic drug monitoring. With the number of requests made at the authors' laboratory, the only rational analysis is one that can measure all three drugs simultaneously. The authors therefore decided to develop an automated high-performance liquid chromatography (HPLC) method. Two milliliters serum, 2.0 mL 10 mmol/L sodium phosphate buffer (pH 5.5), and 150 μL internal standard (trifluoperazine) solution were pipetted into HPLC vials and extracted on an ASPEC XL equipped with 1 mL (50 mg) Isolute C2 (EC) extraction columns and acetonitrile–methanol–ammonium acetate buffer (60:34:6) as extracting solution. Three hundred fifty microliters was analyzed by HPLC; a 150 × 4.6-mm S5CN Spherisorb column with a mobile phase of 10 mmol/L ammonium acetate buffer–methanol (1:9), a flow rate of 0.6–1.7 mL/min, and ultraviolet detection at 256 and 245 nm were used. Reproducibility was 5–12% and the lower limit of quantitation was 10, 1, and 5 nmol/L (4, 0.4, and 2 ng/mL) for haloperidol, perphenazine, and zuclopenthixol, respectively. The method was found to be sufficiently selective and robust for routine analysis. © 2001 Lippincott Williams & Wilkins, Inc.