库仑滴定法测定水果、蔬菜中Vc含量的研究

A METHOD FOR THE DETERMINATIAON OF VITAMIN C IN FRUITS AND VEGETABLES BY COULOMETRIC TITRATION

以1mol·L-1碘化钾和1mol·L-1磷酸(1∶1VV)为电解液,在阳极电生I2与抗坏血酸分子中—CC—不饱和双键发生加成反应,据此以恒电流库仑滴定法进行抗坏血酸的定量测定.测定了多种水果及蔬菜中抗坏血酸含量并与文献方法(碘量法)相对比,结果表明,本法具有设备简单、快速、灵敏,更准确等优点.

The titration was carried out in a mixture of 1.0 mol·L -1 KI-1.0 mol·L -1 H_3PO_4(1∶1V/V)when bromine was generated at the anode. Vitamin C reacted with one mole of bromine with an n value of 2.The advantages of this method are simple,rapid and accurate. The method has been used for the determination of ascorbic acid in fruit juice drink and vegetables with satiafactory results.