包装饮用水中痕量溴酸盐的离子色谱测定法

Determination of trace bromate in packaging drinking water by ion chromatography

目的采用离子色谱氢氧根体系技术,优化检测方法建立包装饮用水中痕量溴酸盐的快速检测方法。方法使用氢氧化钾溶液作为淋洗液,采用InpacAS19阴离子柱(4 mm×250 mm),电导检测器检测,在淋洗液起始浓度为9 mmol/L KOH,进行梯度淋洗程序,进样体积为200μl,流速为1.00 ml/min,抑制电流为115 mA,柱温为30℃,池温30℃的条件下进行检测,运行时间18 min,外标法定量。结果溴酸盐线性范围为2.5~30μg/L,相关系数r≥0.999 3,方法检出限为0.51μg/L,定量下限为1.27μg/L,批内精密度为1.21%~3.40%,批间精密度分别为1.51%~4.09%,加标回收率为98%~104%。结论该研究建立的检测方法灵敏度高,进样量少,选择性好,分析时间短,检测结果稳定可靠,满足包装饮用水中痕量溴酸盐检测的要求。

[Objective] To developed an optimal method for the rapid determination of trace bromate in the packaging drinking water by ion chromatography with hydroxide-selective anion-exchange column. [Methods] By using the InpacAS19 column（4 mm×250 mm）with potassium hydroxide（KOH）solution as eluent,the samples were detected by a conductive detector,with the optimal chromatogrphic conditions of 9 mmol/L KOH for gradient elution,injection volume of 200 μl,flow rate of 1.00ml/min,electric current of 115 mA,column temperature of 30 ℃ and pool temperature of 30 ℃,duration of 18 min. The quantitive analysis was performed on the basis of external standard method.[Results]The linear range of bromate was 2.5-30 μg/L and the correlation coefficient was higher than 0.999 3. The detection limit was 0.51 μg/L and the lower limit of quantitation was 1.27 μg/L. The within-run precisions were between 1.21% and 3.40%,while between-run precisions were between 1.51% and 4.82%,and the average recoveries were between 98% and 104%.[Conclusion]The method has high sensitivity,low sample size,good selectivity,short analysis time,and stable and reliable test result,which meet the requirements for determination of trace bromate in the packaging drinking water.