电位滴定法测定氯代碳酸乙烯酯中的总氯

Determination of total chloric in chloroethylene carbonate by potentiometric titration

建立电位滴定法测定氯代碳酸乙烯酯(CEC)中总氯含量的分析方法,用于指导工业生产。以乙醇为溶剂,增加CEC和水溶液的互溶性,通过在氢氧化钾溶液(200 g/L)中沸水浴加热5 min,使CEC样品中不同形态的含氯化合物全部碱解成氯化钾;以银电极为测量电极,饱和甘汞电极为参比电极,用硝酸银标准溶液滴定氯离子,测定总氯的质量分数。考察碱的类型、浓度、加入量和碱解时间的影响。样品加标回收率为99.75%~100.32%,相对标准偏差(RSD)小于0.5%(n=9)。方法操作简单,精密度和准确度符合要求,对产品质量控制和生产有重要意义。

A method for the determination of total chloric in chloroethylene carbonate(CEC)by potentiometric titration was established for guiding industrial production.Ethanol was used as solvent to enhance the miscibility of CEC and aqueous solution.All forms of chloric compounds in CEC sample were alkaline hydrolyzed into potassium chloride by potassium hydroxide solution(200 g/L)for 5 min in boiling water bath.The chloride was titrated with silver nitrate standard solution to determine the mass fraction of total chloric compounds with the silver electrode as the measuring electrode,the saturated calomel electrode as the reference electrode.The influence of alkali types,alkali concentration,alkali dosage and reaction time was investigated.The recovery rate of samples was 99.75%-100.32%,relative standard deviation(RSD)was less than 0.5%(n=9).The method was simple to operate,the precision and accuracy met the requirements.It was of great significance for product quality control and production.