Multivariate optimization of extraction and cleanup procedure for the analysis of eight neonicotinoid insecticides in honey from Argentina by UHPLC-MS/MS

MICHLIG, MELINA P.; BRASCA, ROMINA; DEMONTE, LUISINA D.; MAGNI, FLORENCIA V.; REPETTI, MARÍA R.

Bologna

Workshop; 14TH European Pesticide Residue Workshop (EPRW); 2022

Neonicotinoid insecticides are widely applied because they provide systemic protection of crops. However, several studies reported their translocation to the nectar and pollen, posing a potential risk to pollinator insects. Seven active compounds from this family, are registered (acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, thiacloprid and thiamethoxam) for a varied set of crops in Argentina. Likewise, beekeeping is a widespread activity in Argentina, where approximately 95% of the local honey production is exported; hence, ensure traceability and quality control along the honey production chain is essential. Here, a QuEChERS-based methodology was optimized to evaluate the content of neonicotinoids in honey samples collected from apiaries located in areas of intensive livestock and agricultural production. Multivariate strategies were implemented to determine the optimal extraction and cleanup conditions of the analytical method to simultaneously analyze eight neonicotinoids. A two-step experimental design method was carried out to determine the optimal extraction and cleanup conditions. Firstly, a two-level fractional design was carried out considering seven independent variables: temperature, pH and time for the sample soaking stage, the concentration of magnesium sulfate and sodium chloride to improve the extraction of the analytes, as well as the amount of C18 and PSA sorbents, were also investigated. After the screening stage, a Box-Behnken design was performed composed of the three significant variables: soaking time and pH, and the amount of PSA. The factorial design methodology combined with the surface response analysis allowed to optimize the process for the efficient extraction of neonicotinoid compounds from honey. The extracts were evaluated on a UHPLC-MS/MS system. The method was validated following the SANTE 12682/2019 guidelines, with recovery percentages between 79 and 120%, and limits of quantitation between 0.25 and 1.00 μg kg-1. In the evaluation of the 151 honey samples, three neonicotinoids were detected at concentrations below 1.5 μg kg-1. Considering that the European MRLs for these neonicotinoids in honey were established at range of concentrations of 0.01 - 0.2 mg kg-1, the detected levels indicated no human health risk from consumption, but potential risks to honey bees from chronic exposure. The obtained data showed that two nitro-substituted neonicotinoids, i.e. imidacloprid and thiamethoxam, dominated the overall distribution in the central region of Santa Fe. To the best of our knowledge, the type of monitoring conducted in this work is the first one for Argentina and should contribute to the worldwide data on exposure of bees to neonicotinoids.