High-performance liquid chromatographic strategies for the determination and confirmation of anticoagulant rodenticide residues in animal tissues.
A comprehensive approach to the analysis of anticoagulant rodenticide residues in animal tissues based on high-performance liquid chromatography (HPLC) has been developed. Residues of warfarin, coumatetralyl, difenacoum, brodifacoum, bromadiolone, diphacinone and chlorophacinone were extracted with chloroformacetone (1:1, v/v). Extracts were cleaned-up by an integrated gel permeation and adsorption chromatographic procedure which divided the rodenticides into two groups. Residues were then determined and confirmed using normal-phase, ion-pair and weak ion-exchange HPLC techniques. Ion-pair gradient separation resolved all seven rodenticides in a single chromatographic analysis. UV detection methods were employed for all seven rodenticides. Use of a diode array detection system permitted additional confirmation of residues down to 0.1 mg kg-1 by matching UV spectra and derivatives of spectra. Sensitive fluorescence detection was possible for the coumarin-based rodenticides but not for diphacinone and chlorophacinone. Post-column pH-switching fluorescence detection methods were shown to be superior to other methods of fluorescence detection of coumarin-based rodenticides. Recoveries from spiked liver tissue were around 90% at levels from 0.05 to 1 mg kg-1. Detection limits of around 0.002 mg kg-1 for most rodenticides and of 0.01 mg kg-1 for warfarin could be achieved with animal tissue extracts.
D000818:Animals; D000925:Anticoagulants / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003374:Coumarins / Q000032:analysis*; D004285:Dogs; D005777:Geese; D006863:Hydrogen-Ion Concentration; D007189:Indans / Q000032:analysis; D008099:Liver / Q000032:analysis; D010573:Pesticide Residues / Q000032:analysis*; D012378:Rodenticides / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
D000925:Anticoagulants; D003374:Coumarins; D007189:Indans; D010573:Pesticide Residues; D012378:Rodenticides; C004662:chlorophacinone