Recently, legislative decisions withdrew or temporarily suspended the use of neonicotinoids and fipronil as seeds tanning in many countries because of their endocrine-disrupting activity imputable to the bees' toxicity. In this study, the occurrence of acetamiprid, fipronil, clothianidin, flonicamid, imidacloprid, nitenpyram, thiacloprid and thiamethoxam was detected in 66 samples of commercial treated corn seeds, collected in the Italian market in the frame of ministerial institutional quality control activity. Because of the lack of a validated analytical protocol for neonicotinoid detection in seeds, a routinely suitable liquid chromatography-tandem mass spectroscopy (LC-MS/MS) analytical method was developed and statistically validated on fortified corn seeds. Survey results demonstrated that 88% of the investigated seed samples showed the presence of residues of clothianidin, fipronil, thiamethoxam and thiacloprid, either individually or simultaneously, with values that ranged from about 0.002 to 20 mg kg(-1), which evidenced the alarming illicit use of these pesticides in seed treatments.
Keywords: bees; insecticides; mass spectrometry; neonicotinoids; seed treatments.