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JA0027 QuEChERS-Based Method for the Multiresidue Analysis of Pesticides in Beeswax by LC-MS/MS and GC×GC-TOF
来源:Journal Of Agricultural and Food Chemistry | 作者:Silvina Niell | 发布时间: 2142天前 | 3395 次浏览 | 分享到:
The validation of an analytical procedure for the determination of pesticide residues in beeswax, an interesting matrix for environmental pollution monitoring, is presented. Using the QuEChERS template, the impacts of wax particle size, sample amount, and cleanup procedure (water addition, dispersive solid phase extraction, freeze-out, and combinations thereof) on extraction yield and coextractive load were studied. Sample preparation through liquid-liquid partitioning between acetonitrile and melted wax (∼80 °C), followed by freeze-out and primary-secondary amine dispersive cleanup, was performed on incurred and pesticide-free samples for 51 residues. Determinations were made through LC-MS/MS and GC×GC-TOF, and the whole procedure was validated. Matrix effects were evaluated, with recoveries between 70 and 120% and RSDs below 20% in almost all cases. LC-MS/MS LOQs ranged from 0.01 to 0.1 mg/kg for most pesticides, but for GC-amenable pesticides, GC×GC-TOF sensitivity was lower (0.1-0.2 mg/kg). This methodology can be applied for routine analysis of pesticide residues in beeswax.

14 There are some other methods for the quantitative analysis of particular groups of pesticides, such as acaricides11,12 or lipophilic pesticides,17 using either LC or GC techniques.2,3,18 Mullin et al. analyzed 259 real samples from beehives in the United States covering a very broad scope of GC- and LC-amenable analytes. A total of 87 different pesticides and metabolites were identified using the QuEChERS approach as sample preparation method. Nevertheless, the evaluation of the analytical method employed was not published.19 The methodologies employed in the studies mentioned above involved mainly beeswax dissolution followed by liquid-liquid extraction and solid phase extraction for cleanup. A simple variation of the QuEChERS method20 allowing the determination of 51 pesticides in beeswax by LC and GC is presented in this work. Thirteen GC-amenable and 38 LCamenable pesticides employed in this study were selected on the basis of their relevance for beeswax as reflected by the frequency of residue findings in beeswax and other apiarian products according to the literature and the pesticides-online

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