为了准确地评价苹果中的维生素C含量,比较了2,4-二硝基苯肼法和紫外分光光度法测定苹果中维生素C的差异.结果表明,前者在波长为500 nm处吸光度最大,水浴时间为3h,温度为37℃.线性回归方程为y=0.232 1x-0.001 2,R2=0.999 5;后者在243 nm处吸光度最大,标准曲线的R2＝0.9984,线形回归方程为y=0.007 5x-0.014.两种方法测定维生素C的结果分别为7.36 mg/100g和7.32 mg/100 g.
Comparison of Two Methods for Detecting Vitamin C in Apple
In order to determine vitamin C in apple, 2, 4-dinitrophenylhydrazine method and UV spectrophotometry were compared. In the 2, 4-dinitrophenylhydrazine method, the maximum absorbance wavelength was 500 nm, the reaction was carried out in 37℃ water bath for 3h. Its correlation coefficient (R2) for standard curve was 0.999 5, linear regression equation was y=0.232 lx-0.001 2. In UV spectrophotometry, the maximum absorbance wavelength was 243 nm, its correlation coefficient (R2) for standard curve was 0.998 4, linear regression equation was y=0.007 5x-0.014 0. The contents of vitamin C detected with these two methods were 7.36mg/100g and 7.32mg/100g, respectively.
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万方数据
维普
