RT info:eu-repo/semantics/article T1 Fast determination of neonicotinoid insecticides in beeswax by ultra-high performance liquid chromatography-tandem mass spectrometry using an enhanced matrix removal-lipid sorbent for clean-up A1 Valverde Bastardo, Silvia A1 Ares Sacristán, Ana María A1 Bernal Yagüe, José Luis A1 Nozal Nalda, María Jesús del A1 Bernal del Nozal, José K1 Beeswax; Core-shell column; Dispersive solid-phase extraction; EMR-lipid sorbent; Neonicotinoid insecticides; UHPLC-MS/MS AB This study is concerned with the development of a simple, rapid analytical method for simultaneously determining seven neonicotinoid insecticides (dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid, acetamiprid and thiacloprid) in beeswax, by means of ultra-high performance liquid chromatography coupled to a quadrupole-time-of-flight mass detector. An efficient sample treatment is proposed (with average analyte recoveries between 93% and 106%) involving solvent extraction with a methanol and ethyl acetate mixture (70:30, v/v), centrifugation, freezing with dry ice, a dispersive solid phase extraction (enhanced matrix removallipid) followed by evaporation. Chromatographic analysis (10.5 min) was performed on a core-shell technologybased column (Kinetex® EVO C18). The method was fully validated in terms of selectivity, ruggedness, limits of detection (LODs) and quantification (LOQs), matrix effect, linearity, uncertainty, trueness and precision. Low LOQs, ranging from 1.2 to 4.9 μg/kg, were obtained in all cases. Finally, the proposed methods were applied to neonicotinoid analysis of twenty one beeswax samples from different Spanish regions, only one of the pesticides (imidacloprid) being detected at low levels (< LOQ). PB Elsevier SN 0026-265X YR 2018 FD 2018 LK https://uvadoc.uva.es/handle/10324/64386 UL https://uvadoc.uva.es/handle/10324/64386 LA eng NO Microchemical Journal, Junio 2018, vol. 142. p. 70-77. NO Producción Científica DS UVaDOC RD 18-nov-2024