ENANTIOSELECTIVE DETERMINATION OF TERAZOSIN IN HUMAN PLASMA BY NORMAL-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY ELECTROSPRAY MASS-SPECTROMETRY

A sensitive and selective analytical method for the enantioselective d etermination of terazosin in human plasma has been developed. The chro matography is based on the normal-phase chiral separation utilizing th e analogue prazosin as the internal standard. The detection involves t he direct introduction of the normal-phase eluent into an electrospray source followed by mass-selective detection. No pre-column derivatiza tion was required prior to analysis. The chiral stationary phase used was Chiralpak AD 100 mmX2.1 mm I.D. (10 mu m particle size). The metho d was utilized to determine the concentrations of terazosin enantiomer s in human subjects following a 5 mg single oral dose. Results were co mpared with those from an enantioselective HPLC-fluorescence method fr om the same subject plasma samples. The LC-MS results confirm with con fidence that the two terazosin enantiomers have different elimination profiles. (C) 1998 Elsevier Science B.V.