Wang Y H, Wong P K
College of Environmental Sciences, Peking University, Beijing 100871, China.
Water Res. 2005 May;39(9):1844-8. doi: 10.1016/j.watres.2005.02.010. Epub 2005 Apr 7.
A simple and rapid headspace method for gas chromatographic determination of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in drinking water was developed. Acidic methanol esterification followed by a headspace technique using a capillary column gas chromatograph (GC) equipped with an electron capture detector (ECD) was applied to determine the levels of DCAA and TCAA in drinking water. The major advantages of this method are the use of acidic methanol as the derivatization agent instead of the hazardous diazomethane, and esterification is carried out in water instead of organic solvent. DCAA and TCAA methyl esters produced in the reaction were determined directly by a headspace GC/ECD method. The linear correlation coefficients at concentrations ranging from 0 to 60 microg/L were 0.992 and 0.996 for DCAA and TCAA, respectively. The relative standard deviations (RSD, %) for the determination of DCAA and TCAA in drinking water were 15 and 21.3%, respectively (n=3). The detection limits of this method were 3 and 0.5 microg/L for DCAA and TCAA, respectively, and the recovery was 68-103.2% for DCAA and TCAA.
建立了一种简单快速的顶空气相色谱法，用于测定饮用水中的二氯乙酸（DCAA）和三氯乙酸（TCAA）。采用酸性甲醇酯化，随后利用配备电子捕获检测器（ECD）的毛细管柱气相色谱仪（GC）顶空技术，测定饮用水中DCAA和TCAA的含量。该方法的主要优点是使用酸性甲醇作为衍生化试剂，替代了危险的重氮甲烷，且酯化反应在水中而非有机溶剂中进行。反应生成的DCAA和TCAA甲酯直接用顶空GC/ECD法测定。DCAA和TCAA在0至60μg/L浓度范围内的线性相关系数分别为0.992和0.996。饮用水中DCAA和TCAA测定的相对标准偏差（RSD，%）分别为15和21.3%（n = 3）。该方法对DCAA和TCAA的检测限分别为3和0.5μg/L，DCAA和TCAA的回收率为68 - 103.2%。
