DETERMINATION OF COUMARIN ANTICOAGULANT RODENTICIDE RESIDUES IN ANIMAL LIVER BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A fast and simpel multi-residue method for the determination of the coumarin-based rodenticides warfarin, coumatetralyl, bromadiolone, difenacoum and brodifacoum in animal liver samples is described. The samples were extracted with Bond Elut silica columns. The coumarin-derivatives were determined by reverse-phase high-performance liquid chromatography, using methanol - 0.035 mol/l acetic acid as mobile phase. They were detected by a fluorescence spectrophotometer after post-column pH-switching or a combination of fluorescence- and UV-spectrophotometer without any such system. Recovery of spiked samples was 75-85%. The practical limits of detection with the use of post-column pH-switching were about 0.005 mu-g/g for each of the coumarin-derivatives, except for warfarin where it was 0.08 mu-g/g.