High-performance liquid chromatography using electrochemical detection for the determination of prazosin in biological samples

For the quantitation of prazosin a sensitive high-performance liquid chromatographic (HPLC) method was developed. This HPLC analysis method uses an electrochemical detection technique for the identification and quantitation of prazosin. In this assay the serum samples were deproteinized by using a simple acetonitrile precipitation technique that was followed by n-hexane extraction. Prazosin in the deproteinized serum sample was separated by an isocratic elution with an ODS Hypersil HPLC column (150 × 4.6 mm) using a mobile phase consisting of 0.05 M Na₂HPO₄-acetonitrile (60:40), pH 8.4. Prazosin that was eluted from the column was detected using a Coulochem II electrochemical detector. The precision of this assay method was assessed by performing inter- and intra-assay by spiking prazosin free fetal bovine serum samples with 20 and 40 ng/ml concentrations of prazosin. In the intra-assay the recovery was 95.40±4.82% and 97.80±3.40%, respectively, for 20 and 40 ng/ml concentrations of prazosin that were used to spike the serum samples. This electrochemical detection HPLC assay method could be very useful in monitoring plasma levels of prazosin.