High pressure liquid chromatographic determination of the rodenticide brodifacoum in rat tissue.

An HPLC method was developed to determine residues of individual isomers of brodifacoum (3-[3-4'-bromo[1,1'-biphenyl]-4-yl)-1, 2, 3, 4-tetrahydro-1-naphthalenyl]-4-hydroxy-2H-1-benzopyran-2-one) in rat tissue. The compound was extracted twice with 10% methanol in chloroform, filtered, and cleaned up by using automated gel permeation chromatography. A final cleanup on a silica gel SEP-PAK was added to protect the analytical column from irreversible adsorption and to reduce analysis time. The analysis was done on a microPorasil column; a UV detector was used for quantitation. Recoveries of brodifacoum added to rat tissue in concentrations of 0.12-5.0 ppm were greater than 90%.