Dissipation of six neonicotinoids in cotton by high performance liquid chromatography and quechers methodology

Neonicotinoids have been identified as the main reason for the colony collapse disorder (CCD) of pollinators, thus making it imminent to estimate the residues of neonicotinoids in a crop that acts as host for the pollinators. A simple Quechers (Quick, Easy, Cheap, Effective, Rugged and Safe) modified and validated method is reported for estimation of residues of six neonicotinoids viz. imidacloprid, thiacloprid, thiamethoxam, acetamiprid, clothianidin and dinotefuran in different substrates (flowers, nectariferous tissues and pollens) of cotton crop using high-performance liquid chromatography with photodiode array detector (PDA). Sample preparation involved the extraction of residues from matrices using acetonitrile followed by clean up using dispersive solid phase tubes. The dissipation and persistence pattern was studied and the half-lives calculated for all the six test insecticides against different substrates to collate it with the earlier reported results. The limit of quantification (LOQ) of the method was 0.01 mg kg⁻¹.