离子色谱法测定饮用水中的5种卤代乙酸

Determination of five halogenated acetic acids in water using ion chromatography

利用IonPac AS19大容量阴离子交换色谱柱对水中的一氯乙酸、二氯乙酸、三氯乙酸、一溴乙酸、二溴乙酸5种卤代乙酸（HAAs）进行了分离,优化了分离条件。通过控制分离温度实现了二氯乙酸（DCAA）与NO2^-的分离;通过梯度洗脱使三氯乙酸（TCAA）与SO4^2-得到较好、较快的分离;通过中和脱气法解决了在大量CO3^2-（HCO3^-）存在时对实验的干扰。DCAA、TCAA的检出限（以3倍信噪比计）分别达到了2.50μg/L和3.75μg/L。5种HAAs在10.0-2 000.0μg/L线性范围内线性相关系数在0.999以上。

The five halogenated acetic acids （HAAs）, monochloroacetic acid （MCAA）, dichloroacetic acid （DCAA）, trichloro acetic acid （TCAA）, monobromoacetic acid （MBAA）, dibromoacetic acid （DBAA）, were separated on an IonPac AS19 column specially designed for oxyhalides, and the separating conditions were optimized. DCAA and nitrite were separated by controlling the temperature. TCAA and sulfate were well separated rapidly by the concentration gradient of mobile phase. The interfering of carbonate （bicarbonate） was eliminated by the method of neutralization vacuum exhausting gas. The experimental results showed that the five HAAs, nitrite, bromide, nitrate, sulfate, etc. can be separated and detected simultaneously, and the detection limits of the DCAA and TCAA were 2.50 μg/L and 3.75 μg/L respectively, and the linearity ranges were from 10.0 to 2 000.0 μg/L with the correlation coefficients of 0. 999. The method is satisfied for the determination of drinking water.