Enantioselective determination of terazosin in human plasma by normal phase high-performance liquid chromatography–electrospray mass spectrometry

• Published in: Journal of Chromatography A Vol. 794; no. 1-2; pp. 45 - 56
• Main Authors: Zavitsanos, A.Paul, Alebic-Kolbah, Tanja
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 23.01.1998
• Subjects: Adrenergic alpha-Antagonists - blood; Chromatography, High Pressure Liquid; Humans; Indicators and Reagents; Mass Spectrometry; Prazosin; Prazosin - analogs & derivatives; Prazosin - blood; Spectrometry, Fluorescence; Stereoisomerism; Terazosin; Terazosin; Prazosin; Enantiomer separation
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(97)00892-3

A sensitive and selective analytical method for the enantioselective determination of terazosin in human plasma has been developed. The chromatography is based on the normal-phase chiral separation utilizing the analogue prazosin as the internal standard. The detection involves the direct introduction of the normal-phase eluent into an electrospray source followed by mass-selective detection. No pre-column derivatization was required prior to analysis. The chiral stationary phase used was Chiralpak AD 100 mm×2.1 mm I.D. (10 μm particle size). The method was utilized to determine the concentrations of terazosin enantiomers in human subjects following a 5 mg single oral dose. Results were compared with those from an enantioselective HPLC–fluorescence method from the same subject plasma samples. The LC–MS results confirm with confidence that the two terazosin enantiomers have different elimination profiles.