磷钼杂多酸光度法测定药物和食品中抗坏血酸

Spectrophotometric Determination of Ascorbic Acid in Medicines and Foods With Phosphorus-molybdenum Heteropoly Acid

本文研究了抗坏血酸在磷钼杂多蓝形成反应中的现象,优选了测定条件,建立了测定其含量的磷钼蓝光度法。测定了波长在820nm、660nm处不同浓度区的摩尔吸光系数,求得其线性方程。线性范围为0.4～24ppm,方法检检限为0.2ppm,相对标准偏差为0.5％,回收率为96～99.6％。对分别溶液法和单一溶液法进行了比较,并成功地用于片剂维生素C的测定。

A new method is presented for spectrophotcmetric determination of ascorbic acid with phosphorusmolybdenum heteropoly blue. The method is based on the reaction of phospholus-molybdenum heteropoly acid with aseorbic acid. Optimum experimental conditions have been established. The determination range of 0.4～24 ppm, the detection limit of 0.2 ppm, the recovery of 96～99.6％, and the variation coefficient of 0.5％ are given. The apparent molar absorptivity has been calculated by determining the absorptivity of solutions of different concentration at 820 and 660 nm, and linear equations are obtained based on the observed data with the aid of computer. The method has been applied successfully to the determination of ascorbic acid in tabellae vitamin C.