Determination of warfarin in the yolk and the white of hens' eggs by reversed-phase high-performance liquid chromatography.

A procedure for the determination of warfarin, an anticoagulant rodenticide, in the white and the yolk of hens' eggs, using reversed-phase high-performance liquid chromatography is described. Liquid chromatography was performed on an octadecylsilane cartridge using methanol and ammonium acetate triethylamine buffer as the mobile phase, with UV detection at 281 nm. Samples (5 g) were analysed after liquid-phase extraction using a mixture of acetone and diethyl ether. Linearity, precision and accuracy of the method were determined in the range of 0.5-8.0 microg. Limits of quantitation for warfarin in the white and the yolk were 0.020 and 0.015 microg/g, respectively. Mean recoveries of warfarin from spiked white and yolk samples were 84.6 and 87.4%, respectively. The analytical method was applied to a fourteen-day experimental study conducted in laying hens that had been orally dosed with warfarin.