Food Analytical Methods ( IF 2.9 ) Pub Date : 2019-11-01 , DOI: 10.1007/s12161-019-01662-w Yuanling Zhao , Xi’ai Hou , Dongmei Qin , Dan Liu
Abstract
In this study, a simple and rapid dispersive liquid-liquid microextraction method was established, and the residuals of four isomers of hexachlorocyclohexane and six kinds of pyrethroid pesticides in milk were simultaneously determined by gas chromatography electron capture detector (GC-ECD). The milk sample was first extracted with acetonitrile and cleaned with primary secondary amine (PSA). Then 0.5 mL of acetonitrile was mixed with 140 μL of cyclohexane and rapidly injected into 3 mL of pure water. After vortexing and centrifugation, the floating phase was removed with a 0.1-mL pipette into the GC-ECD. The type and volume of extraction solvent, volume of disperser solvent, volume of water, vortex time, and amount of salt were optimized. Under optimal extraction conditions, the ten pesticides showed a good linear relationship in a certain concentration range in milk matrix, and the correlation coefficients were greater than 0.99. The limits of detection ranged from 0.07 to 2 μg/kg, and the limits of quantitation ranged from 0.2 to 5 μg/kg. The average recovery rates were between 70.1% and 106.3%, and the relative standard deviations were less than 15.2%. This method can be used for the determination of hexachlorocyclohexane and pyrethroid pesticides in milk and for subsequent research.
中文翻译:
气相色谱电子捕获检测器同时测定牛奶中六氯环己烷的四种异构体和六种拟除虫菊酯类农药的分散液微萃取方法
摘要
本研究建立了一种简便,快速的分散液-液微萃取方法,并通过气相色谱电子捕获检测器(GC-ECD)同时测定了牛奶中六氯环己烷的四种异构体和六种拟除虫菊酯类农药的残留量。牛奶样品首先用乙腈萃取,并用伯仲胺(PSA)清洗。然后将0.5 mL乙腈与140μL环己烷混合,并快速注入3 mL纯水中。涡旋和离心后,用0.1 mL移液管将漂浮相移至GC-ECD中。优化了萃取溶剂的类型和体积,分散剂溶剂的体积,水的体积,涡旋时间和盐的量。在最佳提取条件下,十种农药在牛奶基质中一定浓度范围内呈良好的线性关系,相关系数均大于0.99。检测限为0.07至2μg/ kg,定量限为0.2至5μg/ kg。平均回收率在70.1%至106.3%之间,相对标准偏差小于15.2%。该方法可用于牛奶中六氯环己烷和拟除虫菊酯类农药的测定及后续研究。