瓶装纯净水中卤代乙酸含量研究

Study on the Content of Halogenated Acetic Acids in Bottled Purified Water

建立了气相色谱法同时测定瓶装饮用水中六种卤代乙酸的分析方法。实验以MTBE(叔丁基甲醚)为萃取溶剂,优化了色谱柱类型,前处理条件和衍生时间等分析条件。结果表明,待测物在选用DB-1色谱柱的条件下可获得满意的峰形和较高的分离度;样品55℃的温度下衍生90 min,甲酯化反应已经达到平衡。六种卤代乙酸均可获得最大的衍生效率。优化条件下,待测物在1.0~40.0μg/L范围内线性关系良好,相关系数均大于0.998,检出限可达到0.1μg/L。对五种瓶装饮用水样品进行三水平的加标回收实验,六种卤代乙酸的平均回收率为82.0%~120.0%,相对标准偏差不大于8.5%。该方法前处理过程步骤较多、分析时间适中。电子捕获检测器灵敏度高,可实现对水中卤代乙酸的定量和定性分析。

The method lbr simultaneous determination of six halogenated acetic acids in bottled drinking water by gas chromatography was developed, In this experiment, MTBE （tert butyl ether） was used as extraction solvent to optimize chromatographic column type, pretreatment conditions and derivatization time. The results show that the analyte can obtain satisfactory peak shape and high degree of separation in the selection of DB-1 column under the condition of 90 min derived samples; the temperature of 55 ℃, methyl esterification has reached equilibrium. The maximum derivatization efficiency can be obtained for the six kinds of halogenated acetic acid. Under the optimized conditions, the internal relations of the analytes in the range of 1-40 μg/L are good, the correlation coefficients are greater than 0.998, and the detection limit can reach 0.1 μg/L. Five kinds of bottled drinking water samples were spiked at three levels. The average recovery rate of six kinds of halogenated acetic acid was 82.0 % to 120.0 %, and the relative standard deviation was not more than 98.5 %. The method has many steps and moderate analysis time. The electron capture detector has high sensitivity and can be used for quantitative and qualitative analysis of halogenated acetic acid in water.