污染土壤和底泥中可提取态有机卤化物的分析方法研究

Study on an analytical method of extractable organic halogens in contaminated soils and sediments

选用甲苯 正己烷、丙酮 正己烷两种混合溶剂作为污染土壤和底泥中可提取态有机卤化物的提取剂 ,与乙酸乙脂作为提取剂进行三种溶剂超声法提取效率的比较 ,采用微库仑法进行测定方法改进的研究 .实验结果表明 ,采用 1∶9的丙酮 正己烷混合溶剂的提取效率较高 ,其平均回收率与乙酸乙脂法接近 ,而且回收率范围比乙酸乙脂法波动更小 .以 1∶9的丙酮 正己烷混合溶剂作为提取剂的方法还表明 :无机可溶性卤化物对EOX测定不产生干扰 ,分析方法的最低检出浓度范围为 0 1—0 4mg(Cl) kg,测定范围为 0— 2 5 0 0 0mg(Cl) kg ,添加标准样品的相对标准偏差为 3 38%— 5 0 9% .

Two mixed solvents,toluene/n\|hexane and acetone/N\|hexane were used as extractant for determination of extractable organic halogens (EOX) in contaminated soils and sediments. A comparison of extractable efficiency between the two mixtures and ethyl acetate as an extractant was made using the improved method of ultrasonic extraction and micro\|coulometric determination. The experimental results showed that the extractable efficiency of acetone/N\|hexane ( V/V = 1∶9) was higher than that using other extractants and its recovery rate was close to that of ethyl acetate. There was a small fluctuation in the recovery rate when the acetone/N\|hexane was used. It was also indicated that the soluble inorganic halogens does not interfered the determination of EOX,the lowest detectable concentration is 0.1—0 4?mg(Cl)/kg, the determining range is 0—250 00?mg(Cl)/kg, and the relative standard deviation is 3 38%—5 09 %, when 1∶9 acetone/n\|hexane is used as an extractant.