title: Confirmation of indandione rodenticide toxicoses by mass spectrometry/mass spectrometry.
abstract: Mass spectrometry/mass spectrometry (MS/MS) with collision-activated dissociation (CAD) was utilized to unequivocally distinguish 1,3-indandione rodenticides in 2 cases of anticoagulant toxicosis. Anecdotal evidence provided by the veterinarian in a case involving feedlot cows and physical evidence at the site of occurrence in a similar case involving lambs strongly implicated diphenadione (diphacinone; DP) in both instances. However, high performance liquid chromatography indicated chlorophacinone (CP), not DP, was present in the blood samples obtained from both cows and lambs. Intact 1,3-indandiones exhibit poor gas chromatographic properties, so procedures were developed for analysis by MS/MS using a direct exposure probe for sample introduction. The EI mass spectra of DP and CP contained a base peak at m/z 173, with molecular ions (M+) at m/z 340 and m/z 374 (Cl isotope cluster), respectively. Corresponding MS/MS CAD parent ion spectra of m/z 173 showed an ion of m/z 340 for DP and 374 (Cl cluster) for CP. CAD analysis of the blood extracts showed a parent ion scan of m/z 173 identical to that of CP, with the m/z 374 (Cl cluster). (Additional evidence was obtained by MS/MS examination of the CAD daughter ion spectrum of m/z 374.) Blood extracts from the affected animals revealed CAD daughter ion spectra for m/z 374 identical to that of reference CP. Positive confirmation of CP in both cases led to identification of the source of the toxicant and prevention of further animal exposures.
authors.affiliation: Animal Health Diagnostic Laboratory, Michigan State University, East Lansing 48824.
authors.forename: W E
authors.initials: WE
authors.lastname: Braselton
authors.forename: R D
authors.initials: RD
authors.lastname: Neiger
authors.forename: R H
authors.initials: RH
authors.lastname: Poppenga
mesh_terms: D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel / Q000662:veterinary; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D002855:Chromatography, Thin Layer / Q000662:veterinary; D007189:Indans / Q000032:analysis* / Q000506:poisoning; D013058:Mass Spectrometry / Q000379:methods / Q000662:veterinary*; D010630:Phenindione / Q000031:analogs & derivatives* / Q000032:analysis / Q000506:poisoning; D012378:Rodenticides / Q000032:analysis* / Q000506:poisoning; D012756:Sheep
chemical_list: D007189:Indans; D012378:Rodenticides; C004662:chlorophacinone; C100262:diphenadione; D010630:Phenindione