The determination of the anticoagulant rodenticide brodifacoum in blood serum by liquid chromatography with fluorescence detection.

A sensitive method utilizing reversed-phase liquid chromatography with fluorescence detection has been developed for the analysis of the anticoagulant rodenticide brodifacoum in blood serum. The serum proteins are precipitated with acetonitrile and the supernatant mixed with ethyl ether. The organic phase is separated, evaporated to dryness, and the residue subjected to chromatographic analysis. Extraction efficiencies of brodifacoum at concentrations of 20, 60, and 300 ng/mL were 82.9, 93.4, and 93.8%, respectively, with coefficients of variation (CVs) of 3.52, 4.07, and 3.68%, respectively. The intrarun precision (CV) without an internal standard at concentrations of 20, 60, and 300 ng/mL were 1.93, 4.89, and 1.51%, respectively, and 3.56, 5.94, and 3.66% with an internal standard. The interrun precision over the concentration range of 20-1000 ng/mL ranged from 1.88-6.22% without an internal standard and from 2.07-12.6% with an internal standard. Brodifacoum was measurable to at least the 1-ng/mL level.