分光光度法测定水中六价铬测量不确定度评定

The Uncertainty Evaluation of Analyzing Cr(Ⅵ) in Water with Spectrophotometry

根据测量不确定度评定与表示理论,采用二苯碳酰二肼分光光度法测定水中六价铬的测定不确定,通过计算和评定,得出该测定水中六价铬的测量结果为0.05595 mg/L时,取包含因子k=2(约95%置信概率),扩展不确定度U=0.001 mg/L。该不确定度评价方法在实际工作中具有较强的实用价值。

According to Evaluation and Expression of Uncertainty in Measurement theory,the method uncertainty of analyzing Cr（Ⅵ） in water by 1,5-diphenylcarbazide spectrophotomerty was evaluated.The result showed that extended uncertainty U=0.001 mg/L,when the concentration of Cr（Ⅵ） was 0.05595 mg/L,and the coverage fact or k=2（confidence probability was 95%）.This method was of practical value.