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通过建立气相色谱-质谱联用检测土壤中8种不同有机氯农药残留(α-666、β-666、γ-666、δ-666、p,p′-DDE、`,p-DDD、o,p′-DDT、p,p′-DDT)的方法.土壤样品前处理是加萃取液(丙酮/正己烷=1.5)微波萃取,经脱水过滤浓缩后,用气相色谱-质谱联用法进行检测.在2.4～24.0μg/L质量浓度范围内,各农药的标准溶液的线性关系数在0.9956-0.9998之间.8种有机氯农药的平均回收率在83.6%～108.5%之间,相对标准偏差(RSD)≤10%(n=8),符合农残分析要求.有机氯农药的检出限(S/N=3)为0.1481～0.3871μg/L之间.实验结果表明:p,p′-DDT、p,p′-DDE、p,p′-DDD在有些地方还是有残留,说明它是降解速度相对比较慢的化合物.4种666和o,p′-DDT未检测出,说明它们在土壤中降解的速度还是比较快的.
Through the establishment of gas chromatography-mass spectrometry (GC-MS) to detect the content of 8 different organochlorine pesticide residues (α-666, β-666, γ-666, p’-DDT, p, p’-DDT) .The soil samples were extracted by microwave (acetone / n-hexane = 1.5), and the extracts were concentrated by dehydration and filtered, and detected by gas chromatography-mass spectrometry. The linear correlation coefficients of standard solutions of pesticides ranged from 0.9956 to 0.9998 in the concentration range of 2.4 ~ 24.0μg / L. The average recoveries of the eight kinds of organochlorine pesticides ranged from 83.6% to 108.5%, and the relative standard deviations (RSD) ≤10% (n = 8), in line with the requirements of pesticide residues analysis.The detection limit (S / N = 3) of organochlorine pesticides ranged from 0.1481 to 0.3871μg / L. The experimental results showed that: p, p’- DDT, p, p’-DDE, p, p’-DDD are still some residues, indicating that it is relatively slow degradation of the compounds .4 kinds of 666 and o, p’-DDT undetectable, indicating that they The rate of degradation in soil is still relatively fast.