利用自动电位滴定法测定果汁中维生素C含量

Determination of vitamin C in fruit juice using automatic potentiometer titration

准确测定果汁中维生素C含量对评价果汁加工工艺、储藏条件和果汁品质具有重要意义。本试验应用自动电位滴定仪测定了苹果、脐橙、猕猴桃新鲜果汁中的维生素C含量。结果表明:自动电位滴定法标定结果精确度较高,重现性良好,相对标准偏差为0.27%～0.59%;果汁维生素C加标回收率为93.06%～98.21%,相对标准偏差为0.17%～1.26%。自动电位滴定法操作简便,可用于不同种类果汁或其他饮料维生素C含量的大批量检测。

Aecurate determination of the content of vitamin C is very important for evaluating processing protocol, storage conditions and nutritional value of fruit juice. In this experiment,the automatic potentiometrer titrator was employed to determine the content of vitamin C of fresh juices of apple, navel orange and kiwifruit. The calibration results were high precise with good reproducibility. The relative standard deviations （RSD） were 0.27% to 0.59%. The recovery rates of vitamin C were 93.06% to 98.21% and relative standard deviations were 0.17% to 1.26%. The method was highly practical because of the high accuracy and simplicity and might be suitable for determining the content of vitamin C of various fruit juices or other beverages.