反相合并带流动注射分析法测定维生素C的含量

Determination of Vitamin C by FIAwith Reversed Merging Zone

采用流动注射反相合并带技术，在乙酸介质中，维生素Ｃ与过量的Ｉ￣－＿３反应，剩余的Ｉ＿３￣－在３５０ｎｍ处由检测器检出，信号强度ΔＡ与维生素Ｃ含量在０～５．０×１０￣（－５）ｍｏｌ·Ｌ￣（－１）范围内呈良好的线性关系，相关系数ｒ＝０．９９９５，相对标准偏差ＲＳＤ＝０．４％（ｎ＝１１），采样频率为７０样次／ｈ。

he technique of reversed mergingzones of FIA has been applied to the deter-mination of vitamin C in acetic acid medium,in which vitamin C reacted with I￣-_3 and ex-cessive I_3￣- was determined by the detector at350nm. The linear relationship holds be-tween the signal ΔA and the vitamin C con-centration in the range of 0～5.0×10￣(-5)mol/L,the linear correlation coefficient(r)is 0.9995, the relative standard deviation(RSD)is 0.4%(n=11)and the samplingfrequecy is 70 times/h.