A method for the determination of thiamethoxam in mustard bloom and various matrices collected from honey bee colonies in mustard fields

Bees are at risk with the second generation neonicotinoid insecticide thiamethoxam. To evaluate the risk, first step is to determine its residues in various matrices to which bees are exposed. An easy and simple analytical method is reported for the purpose. The samples (mustard flowers, hive products and dead bees) were extracted and cleaned up by the QuEChERS method. The extracts were concentrated and residues determined by HPLC equipped with C₁₈ column and PDA detector. The retention time of the thiamethoxam was 18.581 min at 272 nm. The repeatability and reproducibility after spiking the samples with 0.01 mg kg⁻¹ thiamethoxam ranged from 0.82 4.08 and 1.68–2.73 per cent, respectively. The average recoveries in various matrices were above 83 per cent. The LOQ and LOD were 0.01 and 0.003 mg kg⁻¹ respectively. The method was applicable to all the matrices.