Comment on 'Urinary Metabolites of Neonicotinoid Insecticides: Levels and Recommendations for Future Biomonitoring Studies in China': Quantification of 5-Hydroxyimidacloprid and Biomonitoring

摘要

We recently read the article of Song et al. on human biomonitoring of urinary metabolites of neonicotinoids with high interest. Our own experiments on the metabolism of imidacloprid after a single oral dose ofmg in a male volunteer do confirm the findings of Song and co-workers that-hydroxyimidacloprid (5-OH-IMI) and imidacloprid olefin are relevant metabolites of imidacloprid in humans. Unfortunatelythe articlelike several othershas a serious shortcoming from an analytical point of view. The metabolism of imidacloprid has previously been described in sufficient detail in mammals;' whereas data in humans are scarce and mostly qualitative. Available studies indicate that-OH-IMI is a major specific metabolite of imidacloprid;howevernot just 5-OH-IMI but one that is hydroxylated at theH-imidazol moiety (1,CAS no.155802-61-2). Thereforeusing the correct-OH-IMI standard material for chemical analyses for human biomonitoring of imidacloprid is a critical first step. For examplein preparation for our controlled studies in humanswe had to synthesize 1 and a ~(13)C_2,~(15)N isotope labeled analogue because the substances were not commercially available at that time.