电位滴定法测定维生素U制剂中维生素U的含量

Determination of Vitamin U in Vitamin U Preparations by a Potentiometric Titration Method

目的:改进维生素U制剂中维生素U的含量测定方法。方法:建立电位滴定法测定维生素U制剂中维生素U的含量,并与现行质量标准的手动滴定法进行比较。结果:电位滴定法测定维生素U的含量不受处方中其他组分、辅料以及滴定过程中产生的沉淀的影响,两种结构的维生素U(氯化甲基蛋氨酸和碘化甲基蛋氨酸)的平均回收率分别为99.47%(RSD=1.0%,n=9)和100.22%(RSD=1.4%,n=9)。3个不同厂家的6批次产品测定结果表明,本法测定结果与现行标准中的手动滴定法测定结果相对误差≤0.5%。结论:该方法操作简单方便、灵敏度高、准确度好,适于各种维生素U制剂中维生素U的含量测定。

Objective：To improve the determination method of vitamin U in vitamin U preparations. Methods： A potentiometric titration method was established for the determination of vitamin U and the results were compared with those of the manual titration method described in the current quality standard. Results：The determination results of vitamin U by the potentiometric titration method were affected by neither the excipients and the other components contained in the preparations,nor the precipitation produced in the ti-tration process. The recoveries for two types of vitamin U （ methylmethinine sulfonium chloride and s-methy-L-methionine iodide） were 99. 47%（RSD=1. 0%,n=9） and 100. 22%（RSD=1. 4%,n=9）, respectively. The determination results of 6 samples from 3 dif-ferent companies detected by the method were basically consistent to those detected by the manual titration method described in the cur-rent quality standards with the relative deviation less than or equal to 0. 5%. Conclusion：The method is simple,accurate and reliable, and can be used for the quantitative determination of vitamin U in various vitamin U preparations.