López-Blanco Rafael, Nortes-Méndez Rocío, Robles-Molina José, Moreno-González David, Gilbert-López Bienvenida, García-Reyes Juan F, Molina-Díaz Antonio
Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, Edif. B-3, 23071 Jaén, Spain.
Institute of Food Science Research, CIAL (CSIC-UAM), Nicolás Cabrera, 9, 28049 Madrid, Spain.
J Chromatogr A. 2016 Jul 22;1456:89-104. doi: 10.1016/j.chroma.2016.06.019. Epub 2016 Jun 6.
In this article we have evaluated the performance of different sorbents for the cleanup step in multiresidue pesticide analysis in fatty vegetable matrices using QuEChERS methodology. The three different matrices tested (olive oil, olives and avocado) were partitioned using acetonitrile prior to cleanup step. Afterwards, the supernatant was purified using different sorbents: C18+PSA (primary secondary amine), Z-Sep(+) (zirconium oxide and C18 dual bonded to silica), Z-Sep (zirconium oxide bonded to silica) and a novel sorbent Enhanced Matrix Removal-Lipid (EMR) whose composition has not been disclosed. The different cleanup strategies were compared for a group of 67 representative pesticides in terms of recovery rates, matrix effects, extract cleanliness and precision using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The best extraction efficiencies in olive oil matrix were obtained using EMR, while the results for olives and avocado were pretty similar amongst the different sorbents with an overall lower performance in terms of matrix effects and recovery rates compared to olive oil data, particularly in olives due to the higher complexity and concentration of coextracted species. On the other hand, the average reproducibility was clearly better when EMR sorbent was employed in all selected matrices for most pesticides (RSD<10% for 45, 52, and 56 pesticides in avocado, olives and olive oil respectively). The best results in terms of matrix effects were also obtained with EMR; with signal suppression lower than 20% for 79%, 16% and 51% of pesticides tested in olive oil, olives and avocado respectively. Using EMR as cleanup sorbent, limits of quantitation using UHPLC-MS/MS, ranged from 0.10 to 90μgkg(-1), allowing their determination at the low concentration levels demanded by current olive oil regulations in most cases.
在本文中，我们使用QuEChERS方法评估了不同吸附剂在富含脂肪的蔬菜基质多残留农药分析净化步骤中的性能。在净化步骤之前，使用乙腈对三种不同的测试基质（橄榄油、橄榄和鳄梨）进行了分配。之后，使用不同的吸附剂对上清液进行净化：C18 + PSA（伯仲胺）、Z-Sep(+)（氧化锆和C18双重键合到硅胶上）、Z-Sep（氧化锆键合到硅胶上）以及一种新型吸附剂增强型基质去除脂质（EMR），其成分尚未公开。使用超高效液相色谱串联质谱（UHPLC-MS/MS），从回收率、基质效应、提取物清洁度和精密度方面对一组67种代表性农药的不同净化策略进行了比较。在橄榄油基质中使用EMR获得了最佳提取效率，而在橄榄和鳄梨中，不同吸附剂的结果非常相似，与橄榄油数据相比，在基质效应和回收率方面总体性能较低，特别是在橄榄中，因为共提取物的复杂性和浓度更高。另一方面，当在所有选定基质中对大多数农药使用EMR吸附剂时，平均重现性明显更好（鳄梨、橄榄和橄榄油中分别有45、52和56种农药的RSD<10%）。在基质效应方面也获得了使用EMR的最佳结果；在橄榄油、橄榄和鳄梨中分别有79%、16%和51%的测试农药信号抑制低于20%。使用EMR作为净化吸附剂，UHPLC-MS/MS的定量限范围为0.10至90μgkg(-1)，在大多数情况下能够满足当前橄榄油法规要求的低浓度水平的测定。
