水中挥发性卤代烃测定的不确定度评定

污水中挥发性卤代烃为国标优先检测项目之一,是污水检测的一个重要参考指标。为了提高挥发性卤代烃测量的准确度,对污水中4种挥发性卤代烃:三氯甲烷、四氯化碳、三氯乙烯、四氯乙烯进行测定,结果表明:不确定度主要来源于系统误差,建议尽量选用不确定度较小的标准溶液,误差较小的移液管和容量瓶,从而减小系统误差;且尽可能的进行多次重复测定,提高测量的精密度、准确度。

Evaluation of uncertainty in the determination about Volatile Halogenated Halohydrocarbon in sewage water

Volatile halogenated hydrocarbo n in sewage was one of the national standard priority detection items, which was an important reference index for sewage detection. In order to improve the accuracy of the measurement of volatile halogenated hydrocarbons,the study measured four kinds of volatile halogenated hydrocarbons in sewage: trichloromethane, carbon tetrachloride, trichloroethylene and tetrachloroethylene. The results showed that the uncertainty mainly comes from the system error. It was suggested that the standard solution with less uncertainty and the pipette and volumetric flask with less error should be selected as far as possible to reduce the system error It was possible to carry out repeated measurement for many times to improve the precision and accuracy of measurement.