Abstract: AIM: To establish a reversed phase highperformance liquid chromatography method for the determination of antipyrine in plasma.Methods: Plasma samples were prepared with acetonitrile.The chromatographic separation was performed on a Kromasil C18 column at column temperature of 30 ℃.The mobile phase, a mixture of 0.025 mol·L^-1 aqueous solution of sodium acetate and acetonitrile (74:26, v v), was delivered at a flow rate of 0.8 ml·min^-1.The detection wavelength was 254 nm and the sample size was 20 μl.Results: Excellent line relationship was obtained in the range of 0.1 to 30 μg·ml^-1 (r=0.9995).The average recovery rate was 93.44%-97.21%.The intra-day and interday coefficients of differentiation were both less than 4.26%.CONCLUTION: The method is simple, accurate and can be used for studies on the model of antipyrine pharmacokinetics.

Key words: antipyrine, reversed phase high-performance liquid chromatography, plasma drug concentration