饮用水中痕量碘的离子色谱积分安培测定法

Determination of trace iodide in drinking water by ion chromatography coupled with integrated amperometric detection

目的建立水中痕量碘的离子色谱分离积分安培检测法。方法采用IonPacASll亲水性阴离子交换柱，以40mmol／L氢氧化钠为淋洗液，通过向银工作电极上施加对应时间的循环电位进行积分安培检测。水样经0．22μm滤膜过滤，直接进样测定。结果碘离子的保留时间小于6min，在1．0-500μg/L浓度范围内，所得回归方程呈良好的线性关系，r=-0．9997。该方法的检出限为0．3μg/L，定量下量检测。限为1．0μg/L，RSD为1．8％，平均回收率在96．0％-103．5％。结论该方法的灵敏度高，操作简便，线性范围宽，准确可靠。

Objective To establish the method for determination of trace iodide in drinking water by ion chromatography coupled with integrated amperometric detection. Methods An anion exchange column, Ionpac AS11 column, was used, and 40 mmolfL NaOH solution was used as elute, iodide was separated and detected by integrated amperometry on a silver working electrode. After filtration by 0.22 μm filter, water samples could be injected directly. Results The retention time of iodide was less than 6 min. A good linear relationship was achieved in the range of 1.0-500 μg/L, r=0.999 7. The limit of detection was 0.3 μg/L and the limit of quantification was 1.0 μg/L. The relative standard deviation of the method for 10 μg/L iodide was 1.8%.The average recoveries for spiked samples were in the range of 96.0%-103.5%. Conclusion The method reveals several advantages including sensitivity, simplicity, broad linear range and accuracy, and it is applicable to the batch analysis of trace iodide in drinking water samples.