METABOLISM, DISTRIBUTION, AND EXCRETION OF DELTAMETHRIN BY LEGHORN HENS

Studies were conducted to determine the metabolic fate of deltamethrin in Leghorn hens. The birds were administered orally 7.5 mg of 14C-labeled (gem-dimethyl or benzyl) deltamethrin/he per day on each of 3 consecutive days, and the elimination of radiocarbon (14C) in excreta and eggs was monitored for five days after the last dose. About 83% of the administered 14C was eliminated during the first 24 h after dosing. Tissue residues were generally very low with the exception of those for liver and kidney. Residues derived from the gem-demethyl portion of the molecule tended to be higher than those from the benzyl moiety. Egg yolks contained considerably higher levels of residues than egg albumen. Various metabolites were isolated and identified by a combination of TLC, GC, GC-MS [gas chromatography mass spectrometry], and high-resolution MS techniques. The compounds identified indicated that the metabolic routes of deltamethrin in laying hens include hydrolysis of ester linkage, followed by hydroxylation of one or both gem-dimethyl groups, hydroxylation of the 2''-, 4''-, 5-, or 6-position of the phenoxybenzyl moiety.