【摘要】 目的建立绿茶中硫丹及虫螨腈残留的固相萃取-气相色谱同时测定方法。方法试样研碎混匀后过45目筛,再经水浸润、乙腈提取、弗罗里硅土固相萃取柱净化后,用HP-5毛细管柱分离、电子捕获检测器检测其中α-硫丹、β-硫丹、硫丹硫酸酯及虫螨腈的残留量。以保留时间定性,外标法定量。结果方法线性范围均为0.02μg/ml~1.00μg/ml,相关系数均≥0.999 8;回收率为78.6%~95.3%;相对标准偏差(RSD)为1.29%~3.31%(n=6);以仪器3倍信噪比计算方法检出限为0.260μg/kg~0.395μg/kg,以10倍信噪比计算方法的定量限为0.866μg/kg~1.32μg/kg。结论该法简便、灵敏、准确,可用于茶叶中硫丹及虫螨腈残留的测定。更多还原

【Abstract】 Objective To develop a method for the determination of endosulfan and chlorfenapyr in green tea by solid-phase extraction coupled with gas chromatography. Methods The samples were homogenized,filtered by 45 screen mesh,and the target pesticides were extracted with acetonitrile and then purified with florisil solid-phase extraction column. The samples were separated with a HP-5 capillary column,and the residues of alpha-endosulfan,beta-endosulfan,endosulfan sulfate and chlorfenapyr were detected with ECD. The retention times were used for qualification and standard curves were used for quantification. Results The linear ranges of the method were within 0. 02 μg/ml-1. 00 μg/ml; the correlation coefficients were ≥0. 999 8. The average recoveries were within 78. 6%-95. 3%; the relative standard deviations( RSDs) were within1. 29%-3. 31%( n = 6),and the detection limit of 3 times signal-to-noise ratio of the instrument was within 0. 260 μg/kg-0. 395 μg/kg,and the limit of quantification was within 0. 866 μg/kg-1. 32 μg/kg calculated by 10 times signal-to-noise ratio. Conclusion The method is simple,sensitive and accurate,and it is suitable to determine the residues of endosulfan and chlorfenapyr in green tea.更多还原