中文摘要：

采用高效液相色谱-紫外检测法测定了对羟基苯丙酮酸烯醇一酮式互变异构动力学．结果表明，在以甲醇与13mmol／LNaH2PO4-Na2HPO4缓冲液（pH为5．91）（体积比为10：90）为流动相，流速O．8mL／min时，对羟基苯丙酮酸烯醇式和酮式在10min内得以完全分离．根据酮式结构的含量测定工作曲线的线性范围为1．0×10^-5～1．0×10^-3mol／L，相关系数R2=0．9988，峰高和保留时间的相对标准偏差为3．4％和0．6％．对羟基苯丙酮酸互变异构符合一级反应动力学，测得其在20℃下的速率常数为k=0．005min^-1，半衰期为t1／2=138．6min．

英文摘要：

The kinetics of keto-enol tautomerism of p-hydroxyphenylpyruvic acid （pHPP） in aqueous solution at room temperature （20 ℃ ） was first investigated by High Performance Liquid Chromatography with UV detection at 216 nm. The result showed that two tautomers could be separated and detected within 10 min by using a mobile phase of 13 mmol/L phosohate and methanol （90 ： 10 v/v; pH5. 91） at a flow rate of 0. 8 mL/min . According to the ketonic form of pHPP, the linear range is between 1.0 × 10^-5-1. 0 × 10^-3 mol/L with correlation coefficient （R2） 0. 998 8. Relative standard deviation （RSD） for retention time and peak height is 3.4% and 0. 6%, respectively. The kinetics of keto-enol tautomerism of pHPP is first-order reaction. Under 20 ℃, the distribution fractions of enolic pHPP, kinetic rate constant and half-life were determined.