G市大学城管网末梢水中二氯乙酸、三氯乙酸含量的测定及煮沸时间对含量的影响

Research on Contents and Boiling Time of Dichloroacetic Acid and Trichloroacetic Acid in the Terminal Tap Water of University City in G City

为了了解G市大学城管网末梢水中二氯乙酸(DCAA)、三氯乙酸(TCAA)含量情况,并通过煮沸法找到去除DCAA和TCAA的最佳时间,实验采集G市大学城五所高校早、中、晚三个时点的管网末梢水,采用气相色谱法检测,考察了分析方法的线性关系、检出限、回收率和精密度,进而应用该分析方法检测DCAA、TCAA的含量.实验结果表明:TCAA在0～160 g·L^(-1)内呈线性关系,直线方程分别为y=0.0089x+0.0096和y=0.0051x-0.01196,相关系数均大于0.999;回收率为98.3%～103.2%,精密度为1.85%～3.09%.五所高校管网末梢水DCAA、TCAA最高含量分别为(5.42±0.09) g·L^(-1)和(4.31±0.13) g·L^(-1),最低含量分别为(2.36±0.07) g·L^(-1)和(1.48±0.09) g·L^(-1),含量均未超出国家标准限值;中午时DCAA、TCAA含量相对较高,随煮沸时间增加,去除率逐渐增高,推荐将管网末梢水煮沸3 min后饮用.

To understand the content of dichloroacetic acid(DCAA) and trichloroacetic acid(TCAA) in the terminal tap water in G city university city,and the best time to remove them by boiling method,and provide the reference for drinking water of residents,teachers and students in the university city.According to the three time points of early(8:00),middle(12:00),late(18:00),terminal tap water of living areas was collected as the sample group in the G city university city.The samples were analyzed using gas chromatography referring to GB 5749-2006.The linear equations,correlation coefficients,precision,minimum detection limit,recovery and precision of experiments were calculated.The good linearity was obtained when the mass concentration of DCAA and TCAA among 0 μg·L^-1~160 μg·L^-1,and both of the correlation coefficients were above 0.999.The recovery was 98.3%~103.2%,the precision was 1.85%~3.09%.The results showed that the highest contents of DCAA and TCAA were respectively(5.42±0.09)μg·L^-1 and(4.31±0.13)μg·L^-1, the lowest contents were respectively(2.36±0.07)μg·L^-1 and(1.48±0.09)μg·L^-1 in the terminal tap water in G city university city. Contents of DCAA and TCAA were higher at noon,and contents were lower in early and late.With the increasing of boiling time,the removal rate increased gradually.Contents of DCAA and TCAA did not exceed the national standard in the terminal tap water of the five universities in G city university city.The contents of DCAA and TCAA were lower in early and late,and were higher at noon.It was recommended that the residents,teachers and students in G city university city boil the terminal tap water for 3 minutes before drinking.