离子色谱法同时测定饮用水中一碘乙酸、二碘乙酸

Simultaneous determination of monoiodoacetic acid and diiodoacetic acid in drinking water by ion chromatography

建立离子色谱法同时测定饮用水中一碘乙酸和二碘乙酸的方法。样品经Na柱、RP柱和滤膜过滤后直接进样分析,采用Ionpac AS19(4.0 mm×250 mm,7.5μm)色谱柱,氢氧化钾梯度淋洗,抑制电导检测进行测定。一碘乙酸、二碘乙酸的质量浓度在0.002~0.1 mg/L范围内与色谱峰面积线性关系良好,相关系数不小于0.9990。采用氢氧根淋洗液和动态量程电导检测器可以获得nS级的噪声,检出限达到ng/L级。自来水和黄河水中均未检出一碘乙酸、二碘乙酸,加标回收率在85.25%~115.00%,测定结果的相对标准偏差为0.49%~3.77%(n=6)。该方法精确度高,回收率和重现性良好,是检测新型碘代酸消毒副产物的可靠方法。

A method was developed for the simultaneous determination of monoiodoacetic acid and diiodoacetic acid in drinking water by ion chromatography.Sample was treated by Na column,RP Column and filtration for direct injection.The method use of Ionpac AS19(4.0 mm×250 mm,7.5μm)column and KOH gradient elution for separation and suppressed conductivity for detection.The mass concentration of monoiodoacetic acid and diiodoacetic acid showed good linear relationship with the peak area in the range of 0.002-0.1 mg/L,and the correlation coefficient were not less than 0.9990.The detection limits were down to ng/L due to the use of hydroxide eluent and dynamic range conductivity detector with nS baseline noise.There was no monoiodoacetic acid or diiodoacetic acid in tap water and Yellow River water,the stangard addition recovery was 85.25%-115.00%,and the relative standard deviations of determination results were 0.49%-3.77%,respectively.The method has high accuracy,good recovery and reproducibility,and is a reliable method for the detection of new iodoacid disinfection by-products.