Rapid Determination of Prazosin in Perfusion Media By HPLC With Solid Phase Extraction

Abstract A method is described for the quantitation of prazosin in tissue culture medium used for in vitro perfusion of human placental lobules. Prazosin was extracted using solid phase cartridges and the samples analysed by high performance liquid chromatography. The analysis utilised a C18 reversed-phase column maintained at 40°C with quantitation by fluorescence detection. The assay was linear to 100 ng/mL, intra-assay coefficients of variation measured at concentrations of 5 and 50 ng/mL were 5.8 and 6.2% respectively and inter-assay coefficients of variation were 4.9 and 2.7% for the same concentrations. The mean recovery of prazosin was 90.9 and 85.2% from solutions with concentrations of 5 and 50 ng/mL respectively. The minimum detectable limit was 0.1 ng/mL and the internal standard for this assay was propranolol. Analysis of a range of endogenous and exogenous compounds likely to be present in pregnancy plasma revealed only minor interference from lignocaine.