Penetration studies and residue determinations of 2,4-dichlorophenoxyacetic acid butyl ester in fertile hen eggs and chicks hatched from treated eggs.

Fertilized hen eggs were topically applied with 2,4-Dichlorophenoxyacetic acid butyl ester (3.1 mg/egg) before starting incubation. During the incubation time 20% of the compound applied on eggs was lost by volatilization. At different incubation times (0, 1, 5, 10 and 15 days) the wash-off technique was applied to fertile hen eggs and residue analyses of 2,4-D ester were determined and quantified by gas chromatography with an electron capture detector. We found that 2,4-D ester began to be detectable at the embryo from the 5th incubation day and the amount of the compound progressively increased during chick embryonic development. Furthermore chicks hatched from treated eggs showed the presence of the compound in all studied tissues and the highest levels were found in organs such as brain and kidney.