气相色谱-质谱法测定饮用水中的卤乙酸

Analysis of Haloacetic Acids in Drinking Water by Gas Chromatography-Mass Spectrometry

参照美国EPA Method 552．3方法中的液-液微萃取、酸化甲醇衍生化技术，以高纯水代替甲基叔丁基醚（MTBE）做溶剂配制标准贮备液，采用气相色谱／质谱联用技术对饮用水中的卤乙酸（HAAs）进行测定。结果表明：在所确立的检测条件下，样品分析时间短，内标、HAAs组分峰在谱图上能够得到很好的分离。低、中、高3个浓度水平的加标水样的HAAs回收率为82％-103％。该方法的检测限：二氯乙酸为0．72μg/L、三氯乙酸为0．44μg/L。用水做溶剂配制的标准贮备液在4℃条件下贮存时，贮存时问为2个月。

Based on liquid-liquid micro-extraction and acidic methanol derivatization methods from EPA Method 552.3, a gas chromatographic-mass spectrometric （GC-MS） method has been studied for determining haloacetic acid （HAAs） in drinking water using ultrapure water instead of methyl tert-butyl ether （MTBE） as solvent for preparing standard stock solution. The results showed that the peaks of l, 2-dibromo propane （internal standard ） and HAAs were separated very well. With the improved method, the recoveries for HAAs （82% - 103% ） were high at concentrations ranging from 5 to 80 μg/L, the detection limits for dichloroacetic acid （DCAA） and trichloroacetic acid （TCAA） were 0.72 and 0.44 μg/L. With the improved method, the runtime could be also significantly reduced without compromising the analytical resolutions. It is also demonstrated that the stock standard was stable under storage for 2 months at 4 ℃.