Simultaneous determination of neonicotinoid insecticides in sunflower-treated seeds (hull and kernel) by LC-MS/MS |
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Authors: | Laura Sánchez-Hernández Mariano Higes María T Martín María J Nozal |
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Affiliation: | 1. I.U. CINQUIMA, Analytical Chemistry Group, University of Valladolid, Valladolid, Spain;2. Bee Pathology Laboratory, Regional Apiculture Center, Marchamalo, Spain |
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Abstract: | A validated analytical method to determine seven neonicotinoids (dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid, acetamiprid and thiacloprid) in sunflower seeds (hull and kernel) using HPLC coupled to electrospray ionisation mass spectrometry (ESI-MS) is presented. Sample clean-up based on a solid–liquid extraction, and the removal of lipid fraction, in the case of kernels, is proposed and optimised. Low limits of detection and quantification were obtained, ranging from 0.3 × 10–3 to 1.2 × 10–3 µg g–1 and from 1.0 × 10–3 to 4.0 × 10–3 µg g–1, with good precision, and recovery values ranged from 90% to 104% for hulls and kernels. The method was applied for the analysis of five thiamethoxam-dressed sunflower seeds and four non-treated seeds, where, besides thiamethoxam, residues of the other neonicotinoid, clothianidin, were also detected and confirmed via tandem mass spectrometry (LC-ESI-MS/MS). Finally, the presence of residues of thiamethoxam and clothianidin in collected sunflower seeds (hulls) coming from coated seeds confirmed the translocation of these neonicotinoids through the plant up to these seeds. |
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Keywords: | HPLC-MS/MS hull kernel neonicotinoid sunflower seed thiamethoxam translocation |
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