加速溶剂萃取-气相色谱-质谱法测定土壤中半挥发性有机物的残留量

采用加速溶剂萃取-气相色谱-质谱法测定土壤中半挥发性有机物的含量。土壤样品以二氯甲烷-丙酮(1∶1)混合溶液进行萃取,所得萃取物用硅酸镁固相萃取小柱净化。在气相色谱分离中用TG-5MS(30 m×0.32 mm×0.25μm)色谱柱进行分离,在质谱分析中采用选择离子监测模式,内标法定量。该方法在1.56~50.0μg/ml相关系数大于0.99,检出限为0.01~0.03 mg/kg,测定下限为0.04~0.12 mg/kg。对土壤中3个添加水平(0.10、0.70 mg/kg和1.50 mg/kg)下的回收率进行了测定,回收率为74.1%~101%,相对标准偏差(RSD)为0.1%~7.1%。该方法样品前处理简单、灵敏、可靠,灵敏度、准确度和精密度均符合检测要求,适用于土壤中半挥发性有机物的检测。

Determination of Semi-volatile Organic Compounds in Soil by Accelerated Solvent Extraction/gas Chromatography Mass(ASE/GC-MS)

Gas chromatography mass(GC-MS)was applied to the determination of semi-volatile organic compounds(SVOCs)in soil with accelerated solvent extraction(ASE).The soil sample was extracted with a mixture of dichloromethane and acetone(1∶1)and the extract was then purified on florisil solid phase extraction column.The SVOCs were separated by TG-5MS column(30 m×0.32 mm×0.25μm)and selected ion monitoring mode was adopted in MS determination,and was quantification by internal standard method.The method of calibration curve was linear in the range of 1.56~50.0μg/ml with coefficient of 0.99,the detection limit is 0.01~0.03 mg/kg,and the lower limit is 0.04~0.12 mg/kg.The recoveries of SVOCs at three levels of 0.10,0.70 and 1.50 mg/kg were from 74.1%~101%with the relative standard deviations(RSDs)of 0.1%~7.1%.The method is simple,sensitive,and efficient with acceptable precision and accuracy to meet analysis requirements.This method is suitable for the detection of SVOCs in soil.