Study on the metabolism and tissue distribution of diazepam in Carassius auratus from angling bait
Objective To study the tissue distribution and metabolic regulation of diazepam(DZP)in Carassius auratus after feeding with positive bait containing DZP.Methods Carassius auratus was selected as the study object and exposed to DZP-enriched bait through gavage,and tissue samples including scales,skin,muscle,plasma,gills,intestines,liver,gallbladder,gonads,and brain were collected at specific intervals ranging from 1 h to 456 h post-exposure.High performance liquid chromatography coupled with tandem high-resolution mass spectrometry was employed to detect DZP and its metabolites—nordazepam(NZP),temazepam(TZP),and oxazepam(OZP)—in these tissues,analyze their distribution and metabolic patterns.Results Following exposure to DZP-enriched bait,DZP rapidly accumulated in Carassius auratus tissues,with substantial residues persisting for up to 456 h.The highest concentrations were primarily found in the gonads,liver and gallbladder,with the gonads consistently showing elevated levels.NZP and TZP emerged as the primary metabolites.Conclusion DZP predominantly exists in its prototype form in Carassius auratus and tends to accumulate in the gonads.The prolonged metabolic cycle of DZP and its metabolites in Carassius auratus indicates potential food safety and health risks for consumers of aquatic products caught with DZP-containing bait.