气相色谱法测定土壤中21种有机氯农药和4种有机磷农药

GC Determination of 21 Organochlorine and 4 Organophosphorus Pesticides in Soil

应用气相色谱法测定土壤中21种有机氯农药和4种有机磷农药(OCP′s及OPP′s)的含量。土壤样品(10g)以丙酮-正己烷(1+1)混合液(200mL)在65℃用索氏提取7h。提取液蒸缩至约2mL,用经固相萃取小柱净化。用上述混合液6mL分3次从柱上洗脱,洗脱液浓缩至1mL供气相色谱分析。测定OCP′s时用CLPⅡ型毛细管色谱柱分离,电子捕获检测器检测;测定OPP′s时用1701型毛细管色谱柱分离,火焰光度检测器检测。21种OCP′s和4种OPP′s在一定的质量浓度范围内与其峰面积呈线性关系。方法的检出限(3S/N)在0.14~0.38μg·kg-1之间。加标回收率在68.0%~125%之间,测定值的相对标准偏差(n=10)在2.8%~5.9%之间。

GC was applied to the determination of 21organochlorine and 4organophosphorus pesticides(OCP′s and OPP′s)in soil.The sample(10g)was extracted for 7hwith 200mL of a mixture of acetone and nhexane(1+1)at 65℃by soxhlet extraction.The extract was evaporated to ca.2mL and purified on SPE column.The column was eluted thrice with aceton-n-hexane(1+1)mixture,2mL of which were used in each elution.The eluate was evaporated to 1mL and used for GC analysis.Separation on CLPⅡcapillary column and detection by ECD were used for determination of OCP′s,and separation on 1701capillary column and detection by FPD were used for determination of OPP′s.Linear relationships between values of peak area and mass concentration of the 21organochlorines and 4organophosphoruses were kept in definite ranges.Detection limits(3S/N)found were ranged from 0.14to 0.38μg·kg-1.Values of recovery found by standard addition method were in the range of 68.0%-125%,with values of RSD′s(n=10)the range of 2.8%-5.9%.