title: Evaluation of zirconium dioxide-based sorbents to decrease the matrix effect in avocado and almond multiresidue pesticide analysis followed by gas chromatography tandem mass spectrometry.
abstract: Two sorbents containing ZrO₂ (Z-Sep and Z-Sep+) were tested as a d-SPE clean-up in combination with the QuEChERS and ethyl acetate multiresidue method in the pesticide residues extraction in avocado. All extracts were analysed using gas chromatography coupled with a triple quadrupole mass spectrometer working in multi-reaction monitoring mode. GC QToF was used to compare the amount of matrix compounds present in the final extracts, prepared according to different protocols. The highest number of pesticides with acceptable recoveries and the lowest amount of coextracted matrix compounds were provided by QuEChERS with Z-Sep. Subsequently, this method was fully validated in avocado and almonds. Validation studies were carried out according to DG Sanco guidelines including: the evaluation of recoveries at two levels (10 and 50 μg/kg), limit of quantitation, linearity, matrix effects, as well as interday and intraday precision. In avocado, 166 pesticides were fully validated compared to 119 in almonds. The method was operated satisfactorily in routine analysis and was applied to real samples.
authors.affiliation: Pesticide Residue Research Group, European Union Reference Laboratory (EURL), Department of Hydrogeology and Analytical Chemistry, University of Almería, Ctra. Sacramento S/Nº, La Cañada de San Urbano, 04120 Almería, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Lozano
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Rajski
authors.forename: Samanta
authors.initials: S
authors.lastname: Uclés
authors.forename: Noelia
authors.initials: N
authors.lastname: Belmonte-Valles
authors.forename: Milagros
authors.initials: M
authors.lastname: Mezcua
authors.forename: Amadeo R
authors.initials: AR
authors.lastname: Fernández-Alba
mesh_terms: D000085:Acetates / Q000737:chemistry; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D027421:Persea / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D027861:Prunus / Q000737:chemistry*; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000085:Acetates; D010573:Pesticide Residues; C007650:ethyl acetate; D015040:Zirconium; C028541:zirconium oxide
keywords: Gas chromatography; High oil matrices; Mass spectrometry; Multiresidue pesticide analysis; Zirconium dioxide