RP-HPLC Determination of Sodium Tiopronin in Plasma

A method of RP-HPLC for the determination of sodium tiopronin in plasma was proposed. Sample of plasma was extracted with acetonitrile and the eluate obtained was evaporated to dryness by N2-blowing at 40 ℃. The residue was dissolved with 10 mg·L-1 NaHSO3 solution and separated by using Agilent C18 column (250 mm×4.6 mm, 5 μm) as stationary phase and a mixture of acetonitrile-H2O (8+92) of pH 2.5 as mobile phase, and the eluate from the column was used for HPLC analysis with UV detector at the wavelength of 203 nm. Linear relationship between values of peak area and mass concentration of sodium tiopronin was kept in the range of 2.5 to 1 000 mg·L-1, with lower limit of determination (10S/N) of 0.65 mg·L-1. The proposed method was applied to the analysis of sample of plasma, giving values of recovery in the range of 102%-107%. Values of intraday and interday relative standard deviation (n=6) were found to be less than 10%.