《水质 化学需氧量的测定 重铬酸盐法》(HJ 828-2017)的实验室方法验证

Potassium Dichromate Method Verification for Chemical Oxygen Demand in Water

通过测定检出限、测定下限、准确度和精密度等特征参数对《水质化学需氧量的测定重铬酸盐法》(HJ 828-2017)进行了实验室方法验证,并探讨国标变更对实际水样测量结果的影响。结果显示,实验室测定化学需氧量的检出限为3.18 mg/L,小于方法要求的4 mg/L;测定下限为13 mg/L,小于方法要求的16 mg/L;对浓度为24.2±1.8 mg/L(编号2001102)以及142±8 mg/L(编号2001105)的有证标准样品进行六次测定,测得均值分别为24 mg/L及141 mg/L,相对偏差分别为6.29%及1.15%,准确度和精密度符合方法要求。对三种类型的水样分别采用新旧国标方法测定,测定结果无显著差异。

The report was based on the standard for the chemical oxygen demand of water quality(HJ 828-2017), measured the detection limit, the lower limit of measurement and other parameters to verify the potassium dichromate method. The influence of GB code revision on real water sample results was also discussed. The results showed that the detection limit of COD in the laboratory was 3.18 mg/L, less than the 4 mg/L required by the method and the lower limit of determination in the laboratory was 13 mg/L, less than the 16 mg/L required by the method. Six laboratory tests were carried out on the certified standard samples with concentrations of (24.2±1.8) mg/L and (142±8) mg/L. The results showed that the average values were 24 mg/L and 141 mg/L, the relative deviations were 6.29% and 1.15%, respectively. The accurate and precision can satisfy the needs of analysis. Three kinds of water samples were measured by new and old national standard method, and the results showed no significant difference.