紫外分光光度法测定尿液中枸橼酸的浓度

目的:建立紫外分光光度法,测定人尿液中枸橼酸药物浓度,以适应于大样本的尿样样本的测定。方法:柠檬酸(又名枸橼酸)在柠檬酸裂解酶的作用下,生成α-酮酸(草酰乙酸),在弱酸条件下,α-酮酸与苯肼生成相应的α-酮酸苯腙,α-酮酸苯腙在330nm处有强的吸收峰,吸光度的变化程度可反映出柠檬酸含量。结果:线性范围为0.1~4mmol/L,γ=0.9953;平均回收率大于90%,低、中、高浓度样品的日内和日间RSD均小于9.00%,且各种条件下血浆样品的稳定性良好。结论:该方法适用于枸橼酸大样本尿药浓度测定。

Determination of the Concentration of Citrate in the Urine by Ultraviolet Spectrophotometric

Objective:To establish an ultraviolet spectrophotometric method to determinate the concentration of citrate in human urine,so as to adapt to the determination of large urine samples.Methods:The citric acid(also known as citric acid)producesα-keto acid(oxaloacetic acid)by citric acid lyase,and under weak acid conditions,α-keto acid and phenylhydrazine are transformed into the correspondingα-phenylhydrazone keto acid.Theα-phenylhydrazone keto acid has strong absorption peak in 330 nm,and the degree of absorbance can reflect the citric acid content.Results:The linearity range was 0.1~4 mmol/L,γ=0.9953;and the average recovery was over 90%.RSDs of within-day and between-day of low,medium and high concentration samples were all less than 9.00%and plasma samples have good stability under various conditions.Conclusion:This method was applicable to the determination of urinary concentration in large samples of citric acid.