水与氯冉酸的荷移反应及其分析应用

Charge-transfer reaction between chloranilic acid with water and its application to water determination

用分光光度法研究了氯冉酸与水的荷移反应，探讨了反应机理，确定了反应条件。氯冉酸与水形成紫色络合物的最大吸收波长为530nm。水量在0．13％～6％范围内呈线性关系，检出限为体积分数0．13％，相对标准偏差小于2％。用本法测定乙醇、面粉及香料中的微量水，与标准方法测定值相符，回收率为97％～102％。

The reaction between chloranilic acid and water in alcohol was studied by spectrophotometric method. The conditions of reaction and the reaction mechanism were investigated. The stable purple complex formed from the reaction of chloranilic acid and water gave the maximum absorption at 530 nm. Beer＇s law was applicable in the range of 0.13% - 6.0% （V/ V）. The limit of detection is 0.13% （ V/ V）. The precision for five repetitive determinations was less than 2% （RSD）. This method is simple, sensitive and accurate. The proposed method was applied to the determination of trace water in flour, food flavor and ethanol. The recoveries of water in these samples were 97% - 102%.