摘要
本文提出一个具有简便、快速、准确等优点的步骤,应用紫外分光光度法测定水果蔬菜中的抗坏血酸(AA)和脱氢抗坏血酸(DHAA),用易配制、耐保存的三氯醋酸(TCA)溶液取代广泛使用、但难以配制和保存的偏磷酸溶液来提取样品中的维生素C(Vc);且在Cu^(2+)溶液里溶入1.0％的蔗糖,来增加Cu^(2+)催化氧化AA的能力,降低实际样品中AA进行氧化还原反应所需温度。
A simple,rapid and accurate procedure for determining ascorbic acid(AA)and dehydroascorbic acid(DHAA)by UV spectrophotometry in fresh fruits and vegetables is described.A widely used,but difficultly prepared and stored Vc extractant,metaphosplioric acid,is substituted with a better reagent,trichloroacetic acid(TCA).In the copper(Ⅱ)solution,1.0% sucrose which enhanced the catalytic action of copper(Ⅱ)on the oxidation of AA is dissolved.So it can lower the temperature which is needed for redox reaction of AA in real samples.
关键词
水果
蔬菜
维生素C
比色法
分析
Vitamin C
ascorbic acid
dehydroascorbic acid
UV spectropho-tometry
fruits
vegetables
