一种快速绿色测定果汁中VC的方法

A quick determining of vitamin C content in fruit juice

目的:建立一种操作简单、分析快速、绿色环保的果汁中VC含量测定方法。方法:基于间接碘量法的两点电位滴定法,该法利用定量KIO_3标准物质与过量KI反应生成定量I_2,在此反应体系中加入样品,最后用Na_2S_2O_3标准溶液滴定剩余碘,两点电位滴定法确定滴定终点。结果:样品测定结果的相对标准偏差在0.47%~1.2%之间,标准回收率在101.0%~102.9%之间。结论:该法是一种简便快速、绿色环保的果汁中VC含量测定方法,具有准确、快速、安全无污染、所需仪器简单的特点,适用于基层农林科研院所推广应用。

Objective. To establish a simple, rapid, environmental-friendly method of determining vitamin Ccontent in fruit juice. Methods ： Two-point potentiometric titration based on indirect iodine quantity method was used.Quantitative KIO3 standard substance with an excess of KI reacted quantitatively to 12, the sample was added to thereaction system, and finally the remaining 12 was titrated by Na2S203 standard solution. Results. The relative standarddeviations of the sample were between 0.47% to 1.2% and the recovery ratios were between 101.0% - 102.9%.Conclusion ： It is an effective and environment-friendly method of determining vitamin C content in fruit juice, whichis accurate, fast-speed, safe and non-pollution. The instrument is simple and this method will be widely used in locallevel agricultural and forestry institute.