基质固相分散萃取—气相色谱法测定土壤中有机氯农药含量

建立了一种基质固相分散萃取—气相色谱法测定土壤中8种有机氯农药含量的方法,优选了固相分散剂及其用量、洗脱溶剂以及土壤样品与分散剂的质量比。实验结果表明,在弗罗里硅土作为分散剂、正己烷和丙酮（体积比为1∶1）为洗脱溶剂、土壤样品与分散剂的质量比为1∶3的优化条件下,8种有机氯农药在50~250 μg/kg范围内表现出良好的线性关系,相关系数大于0.99,加标回收率为60.3%~94.3%,相对标准偏差为6.83%~8.95%。实际土壤质控样测试结果显示,本方法的测试结果在标准值的不确定度范围内,可满足土壤中有机氯农药残留的检测分析。

Determination of organochlorine pesticides in soil by matrix solid phase dispersion-gas chromatography

A matrix solid phase dispersion-gas chromatograph method was established for determination of 8 kinds of organochlorine pesticides in soil. The solid phase dispersant and its dosage,elution solvent and the mass ratio of soil sample to dispersant were optimized. The experimental results show that under the optimum conditions of using florisil as dispersant,n-hexane and acetone（（with 1∶1 of volume ratio） as eluent solution,and the ratio of soil samples to dispersant being 1∶3,the linear range of each organochlorine pesticide is 50-250 μg/kg with correlation coefficient greater than 0.99,their standard addition recoveries are 60.3%-94.3%,and their relative standard deviations are 6.83%-8.95%. Moreover,the determination results of the quality control samples reveal that the determination data are in the uncertainty range of standard value. The developed method can meet the requirements for determination of organochlorine pesticide residues in soil.