RAPID-DETERMINATION OF PRAZOSIN IN PERFUSION MEDIA BY HPLC WITH SOLID-PHASE EXTRACTION

A method is described for the quantitation of prazosin in tissue cultu re medium used for in vitro perfusion of human placental lobules. Praz osin was extracted using solid phase cartridges and the samples analys ed by high performance liquid chromatography. The analysis utilised a C-18 reversed-phase column maintained at 40 degrees C with quantitatio n 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 reco very 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. Analys is of a range of endogenous and exogenous compounds likely to be prese nt in pregnancy plasma revealed only minor interference from lignocain e.