可见分光光度法测定火龙果中维生素C含量的条件优化及前后对比

The condition optimization and comparison of vitamin C content in Pitaya fruit by spectrophotometry

借鉴食品中还原型Vc的测定常用方法,对可见分光光度法测定火龙果中还原型Vc含量的方法进行优化。探讨了浸取液乙酸用量的前处理条件,以及EDTA-2Na用量、乙酸用量、显色剂固蓝盐B用量、反应温度、放置时间等测定条件对测量结果的影响,确定了测定火龙果中还原型Vc的最佳条件。然后用优化前后的测试条件各做了一条标准曲线,利用SPSS软件对两条标准曲线的差异进行了数理统计判断:残差检验、斜率检验、截距检验,得出总体上优化前后两条标准曲线是有差别的。因此利用优化后测定条件来分析火龙果中还原型Vc含量应该更加接近真实值。文章可以为相似的分析过程提供参考。

Based on the common determination method of reducing Vc in food,the visible spectrophotometry method for determination of reducing Vc in pitaya fruit was optimized.The pretreatment conditions of the amount of acetic acid in the extracted liquid and the influence of edTA-2NA,acetic acid,solid blue salt B,reaction temperature and placement time on the measured results were discussed.Then a standard curve was made with the test conditions before and after optimization,and the difference between the two standard curves was statistically judged by SPSS software:residual test,slope test and intercept test.It was concluded that the two standard curves before and after optimization were different on the whole.Therefore,the optimized determination conditions should be used to analyze the reduced Vc content in pitaya fruit,which should be closer to the true value.This paper can provide reference for similar analysis process.