磷钼杂多酸光度法测定沙田柚中维生素C

Spectrophotometric Determination of Vitamin C in Shatian Pomelo by Phosphorus-molybdenum Heteropoly Acid

基于维生素C定量地与磷钼杂多酸反应生成磷钼蓝,通过测定磷钼蓝的吸光度,从而间接地测定维生素C的含量。显色体系最大吸收波长为826.2 nm,维生素C在0.0000-0.01200 mg/m L浓度范围内与A呈良好的线性关系,线性回归方程为A=-0.0067＋30.536ρ（mg/m L）,相关系数r=0.9991。方法用于沙田柚中维生素C的含量测定,结果与药典法相符。

Vitamin C react with phosphorus-molybdenum heteropoly acid to form phosphor-molybdic blue, the content of Vitamin C was determinate indirectly through determination the absorbance of the phosphomolybdic blue. The maximum absorption wavelength of chromogenic system was 826.2 nm, good linear relationship was obtained between A and the concentration of Vitamin C in the range of 0.0000-0.01200 mg/m L, the equation of the linear regression was A=-0.0067＋30.536ρ（mg/m L）, with a linear correlation coefficient was 0.9991. The proposed method had been successfully applied to the determination of Vitamin C in Shatian pomelo, and the results agree well with those by pharmacopoeial method.