间断化学分析仪自动样品空白校正测定地表水中痕量六价铬

研究了以DPC为显色剂，采用AQ2间断化学分析仪自动样品空白校正测定地表水中痕量六价铬的新方法，消除了地表水样本身颜色或浊度对测定的影响。在最佳实验条件下，六价铬浓度在0．0020．10mg／L范围内与吸光度呈良好线性关系，相关系数为0．9997，方法检出限为0．5μg／L，加标回收率在92．5％～105％之间，且具有较好的精密度及准确度。水样测定结果与传统分光光度法相比，无显著性差异。该方法自动扣除样品空白，无需手工样品前处理过程，自动化程度高，操作简单，分析速度快，适合大批量地表水样中六价铬浓度的测定。

Determination of trace hexavalent chromium with automatic sample blank correction in surface water by discrete analyzer

A DPC spectrophotometric method for determination of hexavalent chromium with automatic Sample blank correction by AQ2 discrete analyzer was investigated, which eliminated the influence from sample color or turbidity in surface water. Under optimized experimental con- ditions, it had a good linear relationship in the range of 0.002-0.10 mg/L with correlation coefficient 0. 9997. The method detection limit was up to 0.5μg/L, the spike recovery rate was between 95.5%＂-105%, and the accuracy and precision was pretty good. There was no significant difference when comparing with traditional spectrophotometric method. AQ2 discrete analyzer could perform automatic sample blank correction without the need for sample pretreatment. It could be widely used to measure hexavatent chromium in large quantities of surface water samples with simple operation and high analysis rate.