Guardia-Rubio María, Fernández-De Córdova María Luisa, Ayora-Cañada María José, Ruiz-Medina Antonio
Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Paraje Las Lagunillas, s/n, E-23071 Jaén, Spain.
J Chromatogr A. 2006 Mar 10;1108(2):231-9. doi: 10.1016/j.chroma.2006.01.006. Epub 2006 Jan 23.
In the present work, an analytical multiresidue method has been developed for the analysis of 32 organochlorine, organophosphorus and organonitrogen pesticides at microg kg(-1) levels in virgin olive oil. The method consists of the extraction of the pesticides with acetonitrile saturated in n-hexane followed by a clean-up process based on gel permeation chromatography (GPC) with ethyl acetate-ciclohexane (1:1) as mobile phase to separate the low-molecular mass pesticides from the high-molecular mass fat constituents of the oil. The target compounds were determined in the final extract by gas chromatography (GC) using thermoionic specific (TSD) and electron-capture (ECD) detection. In the case of positive samples, the amounts found were confirmed by GC-MS/MS, being the results in good agreement. Recoveries and RSDs (n = 10) values were 91-124% and 1-8% (GC-ECD), 82-100% and 9-20% (GC-TSD), and 89-105% and 4-14% (GC-MS/MS), respectively. The three proposed methods were applied to samples collected directly in two olive mills located in the Jaén province (Spain). Specifically, 24 samples of virgin olive oil were collected. The most frequently pesticide residues found were the herbicides terbuthylazine and diuron and endosulfan sulfate, a degradation product of the insecticide endosulfan. The herbicide concentration was higher in those oil samples obtained from olives which were collected from the ground after they had fallen down than in those oil samples from olives harvested directly from the tree. The GC-MS/MS developed method was also applied to the analysis of an olive oil sample from a proficiency test spiked with organochlorine pesticides and all the values obtained were within the specified "satisfactory" range.
在本研究中，已开发出一种分析多残留方法，用于测定初榨橄榄油中微克每千克（μg kg⁻¹）水平的32种有机氯、有机磷和有机氮农药。该方法包括用正己烷饱和的乙腈萃取农药，随后基于凝胶渗透色谱（GPC）进行净化，以乙酸乙酯 - 环己烷（1:1）作为流动相，将低分子量农药与油中的高分子量脂肪成分分离。通过气相色谱（GC）使用热离子特异性（TSD）和电子捕获（ECD）检测来测定最终提取物中的目标化合物。对于阳性样品，通过GC - MS/MS确认所测含量，结果吻合良好。回收率和相对标准偏差（RSD，n = 10）值分别为：GC - ECD法为91 - 124%和1 - 8%，GC - TSD法为82 - 100%和9 - 20%，GC - MS/MS法为89 - 105%和4 - 14%。所提出的三种方法应用于直接采集自西班牙哈恩省两家橄榄油厂的样品。具体而言，采集了24个初榨橄榄油样品。最常检测到的农药残留为除草剂特丁津和敌草隆以及杀虫剂硫丹的降解产物硫酸硫丹。从掉落地面后收集的橄榄中获得的油样中的除草剂浓度高于直接从树上采摘的橄榄所制油样中的浓度。所开发的GC - MS/MS方法还应用于一份添加了有机氯农药的能力验证橄榄油样品的分析，所有获得的值均在规定的“满意”范围内。
