Chlorpyrifos and its oxygen analogue: residues in the body tissues of dipped cattle.

Abstract

Residues of chlorpyrifos and its oxygen analogue (diethyl 3,5,6-trichloro-2-pyridyl phosphate) present in the body tissues of cattle and the rate of elimination were determined after multiple dippings in 0.025% emulsion of chlorpyrifos. The residues of chlorpyrifos were preponderantly in the fatty tissues, and the low residues found in other tissues could be attributed to the small amount of fat present. The highest residues in fat occurred 1 week after the 2nd 3rd dippings. No oxygen analogue was detected in any of the tissues.