饮用水中六价铬2种测定方法的比较

目的建立饮用水中微量六价铬的灵敏、快速的测定方法。方法在弱酸性溶液中，水中微量铬（VI）与二苯碳酰二肼和阴离子表面活性剂十二烷基硫酸钠反应形成紫红色三元离子缔合物，正丁醇存在的可被氯仿萃取，在波长550nm处比色定量。结果方法的线性范围为1～40μg/L，最低检测质量为0．1μg，最低检测质量浓度为0．001mg／L，方法的RSD为1．1％～1．4％，回收率为95％～110％。灵敏度是GB／T5750．6—2006《生活饮用水标准检验方法·金属指标》中的二苯碳酰二肼分光光度法的3．8倍。结论该方法灵敏准确，能满足生活饮用水卫生标准检验方法的要求。

Comparison of 2 Methods of Hexavalent Chrome Determinations in Drinking Water

Objective ] To establish the sensitive and rapid determination of hexavalent chrome in drinking water. Methods ] In the weak acid solution, microchromium（ Ⅳ） in the water and diphenylcarbazide reacted with anion active agent and sodium dodecyl sulfate into purplish red ternary iron compound which could be extracted by chloroform and quantified at wavelength 550nm. Results] The calibration curve showed good linearity in the range of 1 - 40μg/L. The minimum detectable concentration was 0. 001 mg/L. The RSD was 1.1% - 1.4% and the recovery rate was 95% - 110%. The sensitivity of this method was 3.8 times that of diphenylcarbazide spectrophotometry of GB/T 5750.6 -2006 ＂Standard testing methods for drinking water o Metal Index＂. Conclusion] This method is sensitive and accurate that can meet the requirements of standard testing methods for drinking water.