原子吸收分光光度法对果蔬型酸奶中Vc含量的测定

Determination of Vc Content of Fruit-Vegetable Yoghurt by the Method of AAS

[目的]建立测定果蔬酸奶中还原型Vc与Vc总量的方法。[方法]用钨酸钠沉淀酸奶中的大分子,过滤得到Vc提取液。采用原子吸收法测定含铜量,间接测定Vc含量,即样液不经DDT还原直接测定还原型Vc;经DDT还原后测定Vc总量。[结果]还原型Vc的RSD为3.2%,平均回收率为96.8%;Vc总量的RSD为3.3%,平均回收率为96.5%。[结论]原子吸收分光光度法精密度高,准确度好,适合用于测定果蔬酸奶中Vc含量。

[Objective] The study aimed to establish the method of determining content of reduced Vc and total Vc. [Method] macromolecule of fruit-vegetable yoghurt were precipitated by sodium tungstate,obtained Vc extract by filtering. The copper content were determined by AAS,Vc content was conducted by indirect determination,reduced Vc was determined directly without DDT reduction; total Vc was determined indirectly with DDT. [Result] The RSD was 3.2%,average recovery was 96.8% of reduced Vc; the RSD was 3.3%,average recovery was 96.5% of total Vc. [Conclusion] AAS had the higher precision and better accuracy,this method was suitable for determining the content of Vc in fruit-vegetable yoghurt.