离子色谱法测定工艺冷媒中的氯离子

Determination of chloride ion in process refrigerant by ion chromatography

建立了离子色谱法测定冷媒中氯离子的分析方法。取冷媒样品1 g置于马弗炉中,以550℃高温灼烧2 h,煮沸溶解10 min后定容至100 mL容量瓶中,采用离子色谱仪对样品溶液进行测定。氯离子的质量浓度在0.20~1.00 mg/L范围内与色谱峰面积线性关系良好,相关系数为0.99991,方法检出限为0.008 mg/L,定量限为0.08 mg/L,测定结果的相对标准偏差为1.7%~2.9%(n=6),样品加标回收率为90.0%~96.7%。与GB/T 14571.5中的溶解稀释法分析结果相比,该方法能够将冷媒中的杂质离子消除,将有机态的氯转化为氯离子,分析结果准确度更高,可用于冷媒中氯离子含量的测定。

An analytical method for the determination of chloride ion in refrigerant by ion chromatography was established.1 g refrigerant sample was burned at 550℃for 2 h in Muffle furnace,boiled and dissolved for 10 min,and then the sample solution was measured by ion chromatography.Under the optimized experimental conditions,the mass concentration of chloride ion has a good linear relationship with the peak area in the range of 0.20-1.00 mg/L,and the correlation coefficient was 0.99991.The detection limit and quantitative limit of chlorine were 0.008 mg/L and 0.08 mg/L,respectively.The relative standard deviation of the determination results was 1.7%-2.9%(n=6),and the standard recovery of the samples was 90.0%-96.7%.Compared with the analytical results of dissolution and dilution method in GB/T 14571.5,this method can eliminate the impurity ions in refrigerant and convert the organic chlorine into chloride ions.The analytical results have higher accuracy and can be used for the determination of chloride ion content in refrigerant.