离子色谱法同时测定饮用水中亚氯酸盐、氯酸盐和高氯酸盐

Simultaneous Determination of Chlorite,Chlorate and Perchlorate in Drinking Water by Ion Chromatography

建立离子色谱法同时测定饮用水中亚氯酸盐、氯酸盐和高氯酸盐的方法。样品过0.22μm水系微孔滤膜后直接进样,进样体积为500μL,以IonPac AS20阴离子交换柱进行分离,以KOH溶液进行在线梯度淋洗,以电导检测器测定。结果表明:亚氯酸盐、氯酸盐和高氯酸盐标准曲线的线性范围均为0.005~0.750mg·L^(-1),检出限(3S/N)分别为0.78,0.56,1.50μg·L^(-1);对实际水样进行3个浓度水平的加标回收试验,得到的回收率为88.0%~104%,89.0%~97.4%,89.2%~94.9%,测定值的相对标准偏差(n=6)均小于2.0%。按此方法分析了36份样品[自来水(12份)、桶装水(12份)和井水(12份)],亚氯酸盐、氯酸盐和高氯酸盐平均检出率分别为22.2%,55.6%,38.9%,残留量均小于标准限值(0.7,0.7,0.07mg·L^(-1))。

A method for simultaneous determination of chlorite,chlorate and perchlorate in drinking water was established by ion chromatography.The sample was filtered by 0.22μm qeuosystem filter membrane,and then introduced into ion chromatography with sample injection of 500μL.IonPac AS20 anion exchange column was used for separation with KOH solution for online gradient elution,and electrolytic conductivity detector was used for determination.The results showed that linearity ranges of chlorite,chlorate and perchlorate were found in the same range of 0.005-0.750 mg·L^(-1),with detection limits(3 S/N)of 0.78,0.56,1.50μg·L^(-1).Test for recorery was made by standard addition method on the actual water samples at three concentration levels,giving recoveries in the ranges of 88.0%-104%,89.0%-97.4%,89.2%-94.9%,and RSDs(n=6)of the determined values were all less than 2.0%.The proposed method was used for the analysis of 36 samples composed of 12 tap water,12 bottled water and 12 well water,and the average detection rates of chlorite,chlorate and perchlorate were 22.2%,55.6%,38.9%,with their residual values all less than the standard limits(0.7,0.7,0.07 mg·L^(-1)).