卤乙酸分析方法(U.S.EPA)的改进

Improvement of US EPA Method for Analysis of Haloacetic Acids

对U.S.EPA Method552.3卤乙酸分析方法进行了改进.参照原方法中液-液微萃取、酸化甲醇衍生化技术,研究了以高纯水代替MTBE作溶剂配制贮备标准液、气相色谱/质谱联用的适宜检测分析条件和控制过程.结果表明,在所确立的检测条件下,样品运行时间短,内标、HAAs组分峰在谱图上能够得到很好的分辨.低、中、高三个浓度水平水样的HAAs回收率为82%～103%,方法检测限:二氯乙酸为0.72μg/L、三氯乙酸为0.44μg/L.用水作溶剂配制的贮备标准液4℃下贮存时间为两个月.

US EPA Method 552.3 was improved for analysis of haloacetic acids （HAAs）. Based on liquid-liquid micro-extraction and acidic methanol derivatization technology from the existing US EPA method 552.3,study was made on the condition suitable for gas chromatography （GC） / mass spectrometry （MS） detection method and control process by using high pure water instead of MTBE as solvent for preparation of stock standard liquid. The result shows that under the determined detection conditions, the sample test time is short, and the peak of internal standard and HAAs can be well resolved. The HAAs recovery rate of water sample at low, medium and high concentration level is 82% - 103% , and the detection limit for dichloroacetic acid and trichloroacetic acid is 0.72 μg/L and 0.44 μg/L respectively. The stock standard liquid prepared by using water as solvent can be stored at 4 ℃ for two months.