An improved sensitive assay for simultaneous determination of plasma haloperidol and reduced haloperidol levels by liquid chromatography using a coulometric detector.
A simple, highly sensitive and specific high-performance liquid chromatographic method that uses a coulometric detector for the simultaneous assay of haloperidol and reduced haloperidol in human plasma has been developed, using bromoperidol as the internal standard. A reversed phase C8 5-microns column (25 x 0.46 cm) and a mobile phase of phosphate buffer (pH 7.0), acetonitrile, and methanol (40:20:40 vol/vol) are used for separating the analytes. The analytes are extracted from alkalinized plasma using a mixture of pentane and isopropanol (95:5 vol/vol) and purified by back extraction into a perchloric acid solution. Teflon tubes with screw caps are used throughout the extraction work. The compounds are oxidized at a potential of +0.90 V against a Ag/AgCl reference electrode. The detection limit of the assay is 50 ng/L using 1 mL of plasma. The average interassay coefficient of variation for samples of concentration 1-40 micrograms/L is approximately 8%. Possible drug interferences in the assay have been studied. The absolute recovery of the method is approximately 80%. The assay has been validated by quantitating 150 schizophrenic patients' samples.
Hariharan
M
M
Department of Psychiatry, University of Michigan Medical School, Ann Arbor 48109-0656.
Kindt
E K
EK
VanNoord
T
T
Tandon
R
R
D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D004563:Electrochemistry; D006220:Haloperidol / Q000031:analogs & derivatives / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D011619:Psychotropic Drugs / Q000097:blood; D013056:Spectrophotometry, Ultraviolet
D011619:Psychotropic Drugs; D006220:Haloperidol; C006820:bromperidol