Simultaneous determination of some phenothiazine derivatives in human blood by headspace solid-phase microextraction and gas chromatography with nitrogen-phosphorus detection.

Chlorpromazine, levomepromazine, promazine, triflupromazine, and trimeprazine were simultaneously determined in human whole blood and plasma by combining headspace solid-phase microextraction and gas chromatography with nitrogen-phosphorus detection. Extraction efficiency for the phenothiazine derivatives was 0.013-0.117% for both sample types. Regression equations were linear [correlation coefficient (r) = 0.9951-0.9999] within the range 2.5-200 ng/0.5 mL for triflupromazine and trimeprazine, and 6.3-200 ng/0.5 mL for chlorpromazine, levomepromazine, and promazine. The limit of detection for each compound was 0.2-3.9 ng/0.5 mL whole blood and plasma. Intraday and interday coefficients of variation for all phenothiazines in both human samples were commonly < 15 and 20%, respectively. We also report the determination of levomepromazine in human plasma after oral administration.