Determination of brodifacoum and bromadiolone residues in rodent and canine liver.
A method to determine residue concentrations of anti-coagulant rodenticides, brodifacoum (BF) and bromadiolone (BD) in liver was developed, using gas chromatography/mass spectrometry. Nine dogs were given 1.1 mg of BF/kg of body weight, PO, in polyethylene glycol 400, one time. Rats were fed BF or BD (via commercial baits) in amounts from 0.28 to 11.25 mg/kg over 1- to 4-day periods. Fresh liver samples were collected at necropsy from all rats and 3 dogs, ground with Na2SO4, and extracted with CHCl3:MeOH (9:1). After evaporation and silica cartridge purification were performed, residues were oxidized with a 0.16M chromic acid solution, and an oxidation product (4-bromobenzoic acid) was partitioned into CHCl3. The methylated derivative (port derivatization with trimethylanilinium hydroxide) was assayed, using gas chromatography/mass spectrometry. Bromadiolone was detected in livers from rats given greater than 6 mg of BD/kg of body weight, but not in livers of rats given 1.25 mg of BD/kg. In contrast, BF was detected (with one exception) in livers from dogs (given 1.1 mg of BF/kg) and from rats given high (11.25 mg of BF/kg) and low (0.28 mg of BF/kg) doses. This protocol, which does not differentiate between BF and BD because of the formation of a common product after chromic acid oxidation, was used to diagnose anticoagulant toxicosis in 3 dogs, 1 human being and 1 llama naturally poisoned.
Ray
A C
AC
Texas Veterinary Medical Diagnostic Laboratory, College Station 77841.
Murphy
M J
MJ
DuVall
M D
MD
Reagor
J C
JC
D015110:4-Hydroxycoumarins / Q000032:analysis* / Q000506:poisoning; D000818:Animals; D002161:Camelids, New World; D002849:Chromatography, Gas; D004283:Dog Diseases / Q000175:diagnosis; D004285:Dogs; D005260:Female; D006801:Humans; D008099:Liver / Q000032:analysis*; D008297:Male; D013058:Mass Spectrometry; D010573:Pesticide Residues / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D012378:Rodenticides / Q000032:analysis* / Q000506:poisoning; D013997:Time Factors
D015110:4-Hydroxycoumarins; D010573:Pesticide Residues; D012378:Rodenticides; C013418:bromfenacoum; C021636:bromadiolone