动力学光度法测定药物、果蔬中的抗坏血酸

Flow Injection Kinetic Spectrophotometric Determination of Ascorbic Acid Based on an Inhibiting Effect

基于在硫酸介质中， 抗坏血酸对草酸根加速重铬酸钾－ 碘化钾／ 罗丹明６Ｇ 这一反应体系具有抑制作用， 建立了动力学抑制光度法测定抗坏血酸的新方法． 方法的线性范围为０－１０ ～４－００ｍｇ／Ｌ， 检出限为０－０８ｍｇ／Ｌ． 该方法已用于维生素Ｃ 药片、维生素Ｃ注射液、西红柿、橙子、西芹、西瓜皮中抗坏血酸的测定， 结果令人满意．

A new flow-injection kinetic spectrophotometric method is proposed for the determination of ascorbic acid.The procedure is based on the inhibiting effect of ascorbic acid on the enhancing effect of oxalate on the potassium dichromate-potassium iodide/rhodamine6G system.The detection limit and linear range are 0 08mg/Land 0 10～4 00mg/L,respectively.This method has been successfully used to determine ascorbic acid in pharmaceuticals,tomato,celery and watermelon rind.