液液萃取-超声辅助衍生化气相色谱法同时测定水中二氯乙酸、三氯乙酸和2.4 - 滴

目的 建立生活饮用水中二氯乙酸、三氯乙酸和2.4 - 滴的液液萃取 - 衍生气相色谱法。方法 水中被测物用甲基叔丁醚萃取，然后在50℃恒温超声下，硫酸 - 甲醇衍生，衍生产物采用DB - 5毛细管柱（30 m×320 μm， 0.25 μm）程序升温分离、电子捕获检测器检测，内标法定量。结果 方法的线性范围为0.003 mg/L～0.400 mg/L，检出限为0.0004mg/L～0.0030 mg/L，回收率为83.4%～109.7%，相对标准偏差为7.63%～9.31%。结论 本法快速，重现性好，灵敏度高，可用于饮用水中二氯乙酸、三氯乙酸和2.4 - 滴的同时测定。

Determination of dichloroacetic acid,trichloroacetic acid and 2.4-dicholrophenoxyacetic acid in drinking water by gas chromatography after liquid-liquid extraction and ultrasound-assisted derivatization

Objective To establish a gas chromatography-based analytical method after liquid-liquid extraction and ultrasound-assisted derivatization for simultaneous detection of dichloroacetic acid, trichloroacetic acid and 2.4-dicholrophenoxyacetic acid in drinking water. Methods The water was extracted with tert-Butyl methyl ether, the extracts were ultrasound-assisted derivatization by Sulfuric acid methanol at 50℃ constant temperature. The derivatives Chromatographic separation was achieved by DB-5(30 m×320 μm, 0.25 μm) with temperature programming and was used inelectron capture detector analysis was completed by internal standard method. Results The linear range of the method was 0.003-0.400 mg/mL, the detection limit was 0.0004-0.0030 mg/L, the average recovery rate was 83.4%-109.7%, and the relative standard deviation was 7.63%-9.31%. Conclusion The method is high-speed, good reproducibility, and high in sensitive, and can be used for the determination of dichloroacetic acid, trichloroacetic acid and 2.4-dicholrophenoxyacetic acid in drinking water.