饮用水中无机阴离子检测方案

抑制型电导检测离子色谱法测定饮用水中的痕量溴酸盐 应 波， 李淑敏， 岳银玲， 鄂学礼 (中国疾病预防控制中心环境与健康相关产品安全所，北京100050) 摘要：建立一种直接进样测定饮用水中痕量溴酸盐的电导检测离子色谱法。选用 Metrosep A Supp 5 阴离子交换分离柱，碳酸盐淋洗液。抑制型电导检测采用化学抑制器和CO， 抑制器顺序双抑制系统。实验结果显示，溴酸根阴离子与常见共存阴离子完全分离，溴酸盐含量在5~100 ug/L范围内具有良好的线性(r=0.9999)，精密度高(相对标准偏差(RSD)<4%)，方法的检出限为0.50 ug/L，样品加标平均回收率为96.1%~107%。该方法操作简单，分离效果好，可与常见阴离子实现同时分析，灵敏度高，重现性好，可作为饮用水中溴酸盐的标准测定方法. 关键词：离子色谱法；溴酸盐；饮用水 Determination of Trace Bromate in Drinking Water by IonChromatography with Suppressed Conductivity Detection YING Bo， LI Shumin， YUE Yinling， E Xueli (Institute for Environmental Health and Related Product Sofety， Chinese Centerfor Disease Control and Prevention， Beijing 100050， China) Abstract： Bromate is a common disinfection by-product produced from the ozonation of sourcewater containing bromide. An ion exchange chromatographic method with suppressed conduc-tivity detection for the determination of trace bromate in drinking water was developed. Theseparation of the bromate in drinking water was achieved on a Metrosep A Supp 5 anion ex-change column and a Metrosep A Supp 4/5 Guard column with a carbonate eluent. A new dualsuppressed system， an MSMⅡ chemical suppressor combined with a CO， suppressor， was usedto suppress the background conductivity， and to improve the detection limit of bromate. Ionchromatographic experiments were carried out by using a Metrosep A Supp 5 anion exchangecolumn with a suppressed conductivity detector and an eluent of 3.2 mmoL/L Na，CO，-1.0mmol/L NaHCO， at a flow rate of 0.65 mL/min. This method had good linearity(r=0.999 9)in the range of5-100 ug/L and high precision (relative standard deviation (RSD)<4%) forthree concentration levels of bromate. The average recoveries of the spiked samples includingtap water， pure water and mineral water were 96.1%-107%， and the detection limit for bro-mate was 0. 50 ug/L. This method has a simple operation procedure， good separation results，high sensitivity and good repeatability. It can be used as a standard method for the determina-tion of bromate in drinking water. Key words： ion chromatography； bromate； drinking water