超声波提取-气相色谱法测定土壤中21种酚类化合物

建立了超声波提取-气相色谱法同时测定土壤中21种酚类化合物的分析方法。用二氯甲烷和正己烷混合溶剂提取土壤中的酚类化合物,提取液经碱性水溶液分配净化,去除非酸性有机杂质,再酸化萃取酚类化合物,浓缩后采用气相色谱-氢火焰离子化检测器进行检测,外标法定量。以10 g土壤样品计,酚类化合物的检出限为0.01~0.06 mg/kg。实际样品添加回收试验的回收率为62.9%~111.4%,相对标准偏差为4.3%~24.0%(n=6),准确度和精密度均较好。结果表明:该法操作方便,净化效果好,可用于土壤中多种酚类化合物的测定。

Determination of 21 phenolic compounds in soil by ultrasonic extraction-gas chromatography

An effective method was developed to determine phenolic compounds in soil by ultrasonic extraction-gas chromatography (GC). The soil sample was extracted with methylene dichloride-hexane (2:1, v/v) for 3 min with the extraction temperature lower than 50 ℃ for 3 times. The extract was purified by alkaline aqueous solution (pH >12), and the phenolic compounds were dissolved in aqueous solution. After the organic solution was discarded, the aqueous solution was adjusted to pH<3 and subsequently extracted with methylene dichloride-ethyl acetate (4:1, v/v) twice. The analytes were determined by GC-FID and quantified by external standard method. The limits of quantification for all tested phenolic compounds were 0.01-0.06 mg/kg in about 10 g soil samples. The recoveries were between 62.9% and 111.4% with the relative standard deviations (RSDs) in the range of 4.3%-24.0% (n=6). The results showed that this method is sensitive, accurate, and suitable for the determination of the 21 phenolic compounds in soil.