液液萃取-液相色谱法测废水中的氯酚

摘要

建立液液萃取-液相色谱法测废水中2,4-二氯酚、2,4,6-三氯酚、五氯酚的方法.对废水样品用硫酸酸化至DH值为2～3,用二氯甲烷20 mL分2次萃取,合并有机相,再用10 mL浓度为0.5 mol/L K2CO3分2次萃取,定容后,采用可变波长紫外检测器进行定量分析.结果表明,3种氯酚的最低检出质量浓度为2.6～ 3.7 μg/L,回收率为88.4％～106％,测定结果的相对标准偏差为2.67％～4.55％,R2为0.9997～0.9999.该方法所需前处理设备少,操作简单,具有较好的准确度和精密度,适用于废水中2,4-二氯酚、2,4,6-三氯酚、五氯酚的检测.%Liquid-liquid extraction-liquid chromatography was used to detect 2,4-chlorophenol,2,4,6-trichlorophenol and 5-chlorophenol.The pH value of the wastewater sample was adjusted to 2-3 by sulfuric acid,and then,20 mL of dichloromethane was used to extract different kinds of chlorophenols two times,meanwhile,the organic phases were also combined.After that,10 mL of K2CO3 (0.5 mol/L) was used to extract chlorophenols two times.The quantitative analysis on the constant volume sample was carried out using variable wavelength ultraviolet detector.The results showed that,the minimum detection limit of the said three kinds of chlorphenols was 2.6-3.7 μg/L,the recovery rate was 88.4％-106％,the relative standard deviation was 2.67％-4.55％,the value of R2 was 0.999 7-0.999 9.It could draw a conclusion that,the said method needed less equipments for pretreatment,easy to manipulate,and had good accuracy and precision,which was suitable for the detection of 2,4-chlorophenol,2,4,6-trichlorophenol and 5-chlorophenol in wastewater.