Cu^(2+)络合物紫外法测定枸橼酸钾的含量

Measurement of potassium citrate by UV spectrophotometry of Cu^(2+)complex

目的:确定测定枸橼酸钾含量的方法。方法:利用枸橼酸盐与 Cu^(2+)络合,络合物在紫外区有特定吸收波长,用紫外分光光度法测定枸橼酸钾缓释片中枸橼酸钾的含量,且用钾离子选择性电极法对该络合物紫外法进行了平行验证。结果:枸橼酸钾与硫酸铜形成络合物时最大摩尔比为1:1,枸橼酸钾浓度在20～50μg·mL^(-1)范围内,测定波长为(240±1)nm,吸收度与浓度呈良好线性关系,平均回收率(n=5)为100.5%(RSD 为0.83%)。结论:方法准确、简单、快速,可作为枸橼酸钾缓释片中枸橼酸钾的含量测定方法。

Objective：To determine the method to mesure the content of potassium citrate. Methods：To measure the content of potassium citrate by UV. Potassium citrate reacted with Cu^2＋ to form a complex compound which had a specific absorption wavelength at 240 nm. The ion selective electrode analytic method was used to make the preliminary appraisal and compared with the complex compound method. Results：The complex compound molar ratio was 1 ： 1. And there was satisfying linearization between the absorbency from UV and the concentration of the potassium citrate in 20 -50 μg· mL^-1. The average recovery（ n = 5 ） was 100. 5% and RSD 0. 83%. Conclusion：The method is accurate, simple, rapid, and can be used to measure potassium citrate in its the sustained - release tablets.