小麦子粒中五种有机磷农药多残留分析方法研究

采用索氏提取法和溶剂提取法对小麦子粒中的甲胺磷、乙酰甲胺磷、乐果、甲基对硫磷、马拉硫磷进行前处理.采用SUB~(TM)-5型毛细管柱、NPD(Ni~(63))在优化的气相色谱条件下,对添加的5种农药的标准样品进行检测,结果显示,方法的平均回收率均在75.0%以上,相对标准偏差为3.52%-9.74%,最低检测限分别是0.0012mg.kg~(-1),0.0019 mg·kg~(-1),0.0026mg·kg~(-1),0.0031mg·kg~(-1)和0.004 4 mg·kg~(-1).同时,确立了以氧化乐果为内标物的样品定量分析方法,内标物氧化乐果在0.05-3.20 mg·L~(-1).浓度范围内线性回归方程为y=17.7436 x+1.2749.R~2=0.9898.本方法准确、简便、重现性好.采用同样的试验方法还获取了所采3个批次实际样本的残留结果.

Detection of 5 Organophosphorus Pesticide Residues in Wheat Grain

The residue of Methamidophos,Acephate,Dimethoate,Parathionmethyl and Malathion in wheat grains were extracted and purified by Soxhlet and solvent extraction.The prepared analytical samples were analyzed by GC-NPD(Ni~(63))on the optimized chromatographic conditions with SUB~(TM)-5 column.The results showed that the average recovery were all more than 75.0%.and the relative standard deviations were 3.52%-9.74%after spiked pesticides into wheat grain.The detection limit was,0.0012mg/kg,0.0019ms/kg,0.0026ms/ks,0.0031mg/kg and 0.004 4 mg/kg respectively.At the same time,the inter-standard quantitative method based on omethoate was established and its linear regression equation and the correlation coefficient Wag y=17.743 6x+1.2749 and R~2=0.9898.respectively.Using this method,3 samples were analyzed.As a result,this method Was. Simple,accurate and precise for these 5 organophosphorus pesticides detection.