方波溶出伏安法测定果蔬中Vc的方法研究

Study on Detection Methods of Vc in Fruits and Vegetables by Square Wave Stripping Voltammetry

[目的]探索用方波溶出伏安法测定果蔬中Vc的最佳测定条件。[方法]以方波溶出伏安曲线影响因子为研究对象,改变其中的任意一个影响因子,在其他影响因子不变的情况下,找出最好的曲线,建立方波溶出伏安法测定果蔬中Vc的最佳体系。[结果]选择pH值为6左右的柠檬酸钠(柠檬酸根无影响)、盐酸、氢氧化钠的混合液为底液,以-0.4 V为富集电位搅拌富集2 m in后平衡10 s,以电位增量0.35 mV,方波周期13 s,方波幅度8 mV,记录方波溶出伏安曲线,依据最佳试验条件采用标准加入法测量蔬菜中的Vc是最理想的方法。[结论]该方法便捷而实用,特别是用于成分复杂的果蔬试样,有良好的推广前景。

[Objective] The aim was to explore the optimum detection condition of Vc in the fruits and vegetables by square wave stripping voltammetry. [ Method] With the influencing factors of square wave stripping voltammetry curve as studying object, the best curve was found by changing any one of the influencing factors on the condition of other influencing factors without change, and the optimum system of the detection of the Vc in the fruits and vegetables by square wave stripping vohammetry was established. [ Result] Selecting mixed solution （pH as 6） of sodium citrate, hydrochloride and sodium hydroxide as the base solution, with - 0.4 V as the accumulation potential to stir and enrich for 2 min and then balance for 19 s, the square wave stripping voltammetry curve was recorded with the potential increment of O. 35 mV, square wave cycle of 13 s and square wave amplitude of 8 mV. It was an ideal method for the detection of Vc in the fruits and vegetables by the standard addition method according to the optimum experimental conditions. [Conclusion] The method was convenient and practical, and had good popularizing prospect especially for the fruit and vegetable samples with complicated composition.