动力学荧光法测定药物、水果、蔬菜中的维生素C

Kinetic-fluorimetric Determination of Vitamin C in Pharmaceutical, Fruit Juites and Vegetubles

提出了动力学荧光法测定维生素C的新方法。该法基于脱氢抗坏血酸(DAsA)对还原型罗丹明B在钒(Ⅴ)催化下自动氧化的活化作用。在pH为3.7的HAc-NaAc缓冲溶液中,还原型罗丹明B在钒(Ⅴ)催化下的氧化反应速度与DAsA的浓度成正比,采用固定时间法,测定在λ_(ex)=554 nm,λ_(em)=580 nm时的荧光强度。DAsA的线性范围为0～4.0×10^(-7)mol/L, 检测限4.0×10^(-9)mol/L。用该法测定药物、水果、蔬菜中维生素C含量,回收率在93%～108%之间。

A new method is presented for kinetic-fluorimetric determination of vitamin C. Thismethod is based on the activating effect of dehydroascorbic acid on the aerial oxidation ofreduced rhodamine B (RRB) in the present of vanadium (Ⅴ), which acts as a catalyst. In abuffer solution of HAc-NaAc. (pH 3.7), the oxidate reaction of RRB in the present of V(Ⅴ)is directly proportional to the concentration of vitamin C under the described condition.Fluoresence intensity is measured by the fixed-time method. The linear range of determinationfor vitamin C is 0～4.0×10^(-7)mol/L. The detection limit is 4.0×10^(-9)mol/L and the recoveryrate of vitamin C 93%～108%.