摘要
目的:为能及时有效地运行《生活饮用水标准检验方法第10部分:消毒副产物指标》(GB/T 5750.10—2023)中规定的三卤甲烷新检测方法,对气相色谱法测定生活饮用水中5种挥发性氯化消毒副产物三卤甲烷含量的不确定度进行评定。方法:依据《测量不确定度评定与表示》(JJF 1059.1—2012)建立数学模型,对气相色谱法测定生活饮用水中5种三卤甲烷(三氯甲烷、四氯化碳、二氯一溴甲烷、一氯二溴甲烷及三溴甲烷)进行不确定度评定。结果:当饮用水中5种三卤甲烷含量分别为1.97μg·L^(-1)、2.01μg·L^(-1)、1.96μg·L^(-1)、2.03μg·L^(-1)和1.98μg·L^(-1)时,包含概率为95%,包含因子k=2,其扩展不确定度分别为0.21μg·L^(-1)、0.16μg·L^(-1)、0.14μg·L^(-1)、0.16μg·L^(-1)和0.24μg·L^(-1)。结论:通过对不确定度的分析,发现标准曲线拟合残差是气相色谱法测定生活饮用水中5种挥发性氯化消毒副产物不确定的主要来源。实验操作时应注意操作规范,提高标准曲线的检测次数,降低曲线拟合不确定度。
Objective:In order to timely and effectively operate GB/T 5750.10—2023,the uncertainty of the determination of five volatile chlorinated disinfection by-products trihalomethanes in drinking water by gas chromatography was evaluated.Method:According to JJF 1059.1—2012,a mathematical model was established to evaluate the uncertainty of five trihalomethanes(chloroform,carbon tetrachloride,dichloro-bromomethane,chlorodibromomethane and tribromomethane)in drinking water by gas chromatography.Result:When the contents of the five trihalomethanes in drinking water were 1.97μg·L^(-1),2.01μg·L^(-1),1.96μg·L^(-1),-12.03μg·L and 1.98μg·L^(-1),respectively,the inclusion probability was 95%,and the inclusion factor k=2 had extended uncertainties of 0.21μg·L^(-1),0.16μg·L^(-1),0.14μg·L^(-1),-10.16μg·L and 0.24μg·L^(-1),respectively.Conclusion:Through the analysis of uncertainty,it is found that the standard curve fitting residuals are the main source of uncertainty for the determination of five volatile chlorination by-products in drinking water by gas chromatography.Attention should be paid to the operation specification during the experimental operation,so as to increase the number of detections of the standard curve and reduce the uncertainty of curve fitting.
作者
周晓军
ZHOU Xiaojun(Laboratory Department of Sheyang Disease Control and Prevention Center,Sheyang 224300,China)
出处
《食品安全导刊》
2024年第4期68-73,共6页
China Food Safety Magazine
