Department of Food Science and Technology, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran.
Food and Drug Safety Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
J Sep Sci. 2020 Sep;43(18):3674-3682. doi: 10.1002/jssc.202000507. Epub 2020 Aug 19.
A sample pretreatment method based on the combination of a three-phase solvent extraction system and deep eutectic solvent-based dispersive liquid-liquid microextraction has been introduced for the extraction of four organochlorine pesticides in cocoa samples before their determination by gas chromatography-electron capture detection. A mixture of sodium chloride, acetonitrile, and potassium hydroxide solution is added to cocoa bean or powder. After vortexing and centrifugation of the mixture, the collected upper phase (acetonitrile) is removed and mixed with a few microliters of N,N-diethanol ammonium chloride: pivalic acid deep eutectic solvent. Then it is rapidly injected into deionized water and a cloudy solution is obtained. Under optimum conditions, the limits of detection and quantification were found to be 0.011-0.031 and 0.036-0.104 ng/g, respectively. The obtained extraction recoveries varied between 74 and 92%. Also, intra- (n = 6) and interday (n = 4) precisions were less than or equal to 7.1% for the studied pesticides at a concentration of 0.3 ng/g of each analyte. The suggested method was applied to determine the studied organochlorine pesticide residues in various cocoa powders and beans gathered from groceries in Tabriz city (Iran) and aldrin and dichlobenil were found in some of them.
介绍了一种基于三相溶剂萃取体系和基于深共晶溶剂的分散液液微萃取相结合的样品预处理方法，用于提取可可样品中的四种有机氯农药，然后通过气相色谱-电子捕获检测进行测定。将氯化钠、乙腈和氢氧化钾溶液的混合物加入可可豆或可可粉中。混合后涡旋和离心，收集上层（乙腈），并与几微升 N，N-二乙醇铵：戊酸深共晶溶剂混合。然后迅速注入去离子水，得到浑浊溶液。在最佳条件下，检测限和定量限分别为 0.011-0.031 和 0.036-0.104ng/g。所得萃取回收率在 74%至 92%之间变化。此外，在 0.3ng/g 每种分析物的浓度下，研究的农药在 0.3ng/g 的浓度下，日内（n=6）和日间（n=4）精密度均小于或等于 7.1%。该方法应用于测定来自伊朗大不里士市杂货店的各种可可粉和可可豆中的研究有机氯农药残留，发现其中一些含有艾氏剂和敌草隆。
