生活饮用水中二氯乙酸三氯乙酸检测方法的改进

目的改进和优化生活饮用水中二氯乙酸三氯乙酸气相色谱检测方法。方法样品在酸性条件下萃取，再经衍生反应，采用恒温方式毛细管色谱柱分离、ECD检测器气相色谱法测定，内标法定量。结果经改进后的方法通过提高衍生温度为60℃，衍生时间缩短为90min，柱温恒温为90cC，二氯乙酸、三氯乙酸出峰时间缩短。二氯乙酸、三氯乙酸在0-1001xg／L具有良好的线性，相关系数〉0．999，相对标准偏差RSD2．9％～8．8％，回收率为86％一95．4％。结论通过改进优化样品萃取、衍生及色谱条件，缩短了检测时间，减少了试剂的用量。大大提高了工作效率、节约了检测成本，有利于大批水样的分析测定。

The improvement of detection method for dichloroacetic acid and trichloroacetic acid in Drinking Water

Objective To improve and optimize the detection method of gas chromatography in drinking water.Methods The sam- ple was extracted at an acidic pH.After the derivatization reaction,the sample was quantified by capillary chromatographic column in thermostatic mode, gas chromatography with an electron capture detector （EDC） and internal standard method.Results After im- proving the derived temperature which was 60 ℃, the derived time was shorten to 90 min,the constant column temperature was 90℃, the appearance time of dichloroacetic acid and trichloroacetic acid was shorten.The dichloroacetic acid and trichloroacetic acid at 0--100μg/L obtained a good linear,the correlation coefficient was above 0.999,the relative standard deviation （RSD） was 2.9%-8.8%, coefficient of recovery is 86%--95.4%.Conclusion Through the optimization of sample extraction, derivatization and chromatographic conditions, the testing time of sample was shorten,reagent dosage was reduced.Improving the efficiency of opera- tion enormously,the detection expense was shorten, it facilitates the analytic determination of large quantities of water samples.