分光光度法测定大枣中的维生素C含量

Determination of Vitamin C Content in Ziziphus Jujuba by Spectrophotometry

目的：建立大枣中维生素C含量的测定方法。方法：用乙酸从大枣中提取维生素C，由维生素C形成脎，于波长490nm处测定脎的吸光度。结果：维生素C标准溶液的浓度在8～16μg／ml范围内线性关系良好（r=0．9997），平均回收率为99．76％，大枣中含维生素C4．752mg／g，与传统碘量法相比，测定结果基本一致。结论：本方法操作简便，结果可靠，重现性好，可作为大枣中的维生素C含量测定方法。

Objective：To estahlish a method for the determination of content of vitamin C in Ziziphus jujuba. Method ： Vitamin C was extracted from Ziziphus jujuba by HAc, and the osazone was formed by dealing with vitamin C. Its absorption was measured in 490 nm by spectrophotometry. Result ： Vitamin C had fine linear response （r =0. 999 7, ）in the concentration range of 8 ～ 16μg/ml,the recovery was 99.76%. There is 4.752 mg Vitamin C in 1 g Ziziphus jujuba, and the result obtained was similar to traditional titration of iodine. Conclusion：This method employed in this study is convenient and reliable with good repetition.