气相色谱法测定饮用水中二氯乙酸、三氯乙酸的检测方法探索

Exploration of Determination of DCAA and TCAA in Drinking Water with Gas Chromatography

为方便检测,对《生活饮用水标准检验方法消毒副产物指标》(GB/T 5750.10—2006)中气相色谱法测定二氯乙酸(DCAA)、三氯乙酸(TCAA)进行了简化和验证试验。结果表明,DCAA和TCAA的加标回收率分别为91.2%~116.0%和92.7%~113.0%,精密度小于5.0%,证明该试验可以在水样中直接加入硫酸-甲醇溶液衍生,使水样中卤乙酸形成卤代乙酸甲酯,加入正己烷萃取后进入毛细管柱气相色谱柱进行分离,用电子捕获检测器(ECD)检测,以保留时间定性、外标法定量。

A simplified test method for DCAA and TCAA by gas chromatography in GB/T 5750.10—2006 was verificated for convenience.Results showed that standard addition recovery rate of DCAA and TCAA were 91.2%~116.0%and 92.7%~113.0%respectively,RSD was less than 5.0%,the experiment of directly adding sulfuric acid-methanol solution in water samples to form halogenated acetic acid methyl acetate in water,after joining n-hexane extraction capillary column gas chromatography column separation,an electron capture detector(ECD),retention time was qualitatively determined and the amount of these two DBPs were quantitatively determined with external standards qualitative and quantitative external standard method.