HPLC assay for 2-(3-aminopropylamino)ethanethiol (WR-1065) in plasma

A high pressure liquid chromatography (HPLC) plasma assay for WR-1065 is described which is both precise (coefficient of variation < 5%) and accurate (% average deviation ≤ 6.1) throughout the concentration range from 1 to 500 μg/mL of plasma. The analyte is separated by HPLC and detected with a thiol specific electrochemical transducer cell. The detector response is linear over the ranges 1 to 10 μg/mL (R 2 = 0.995), 10 to 100 μg/mL (R 2 = 0.995), and 100 to 500 μg/mL (R 2 = 0.974). The absolute retention times for WR-1065 and WR-1729 are 9 and 12 minutes, respectively. The assay uses 100 μL of plasma and requires a total chromatography cycle time of 40 minutes. The method has been found suitable for the determination of WR-1065 in plasma from a beagle dog after i.v. administration of S-2-(3-aminopropylamino)ethyl phosphorothioate (WR-2721).