液液萃取/气相色谱法测定废水中的三氯甲烷

建立了液液萃取/气相色谱法测定水中三氯甲烷的分析方法。选取石油醚、四氯化碳、环己烷、二硫化碳四种有机溶剂作为三氯甲烷萃取剂,确定了萃取方法和萃取次数,配制4种标准系列溶液,并对标准溶液和萃取溶液进行色谱分析。结果表明:4条标准曲线相关系数>0.9950,标准偏差<4%,加标回收率>75%。其中,石油醚的萃取效果最好为5.88 mg/ml,标准偏差为1.09%,加标回收率最高为99.21%,最低检出限为5.56×10-3mg/L。二硫化碳萃取效果最差为3.15 mg/ml,标准偏差为3.89%,加标回收率75.63%,最低检出限为9.58×10-2mg/L。环己烷和四氯化碳介于两者之间。该方法具有重现性好、准确度高、快速、简便的特点,为三氯甲烷的萃取研究提供一定的参考价值。

Determination of Trichloromethane in Wastewater with Liquid-liquid Extraction/Gas Chromatography

An analytical method of trichloromethane in water with liquid-liquid extraction/gas chromatography was established.Trichloromethane was extracted from four organic solvents such as petroleum ether,carbon tetrachloride,cyclohexane and carbon disulfide.The extraction method and the extraction time were determined,standard solutions of four series were prepared and then standard solution and extraction solution were analyzed with gas chromatography.The results showed that four correlation coefficients of standard curve were over 0.995 0,the standard deviations were smaller than 4% and the recovery rates were over 75%.The extraction efficiency of petroleum ether was the best(5.88 mg/ml),the standard deviation was 1.09,the recovery rate was 99.21% and the limit of detection was 5.56×10-3mg/L.The extraction efficiency of carbon disulfide was the worst(3.15 mg/ml),the standard deviation was 3.89%,the recovery rate was 75.63% and the limitation of detection was 9.58×10-2 mg/L.Carbon tetrachloride and cyclohexane were between petroleum ether and carbon disulfide.This method with good reproducibility and high accuracy was rapid and simple and it can be provided as valuable references in the research on the trichloromethane extraction.