Ivermectin in reindeer feces: Determination by HPLC

An assay method for the determination of ivermectin in reindeer feces was d eveloped. Ivermectin was quantified by high-performance liquid chromatograp hy and fluorescence detection after extraction (acetone, isooctane), cleanu p (C-18 solid-phase extraction column), and derivatization to a fluorescent derivative using N-methylimidazole and trifluoroacetic anhydride. Concentr ation calculations were based on calibration lines found from analyses of s tandards prepared in feces. Abamectin was used as internal standard. Iverme ctin was determined over a wide concentration range in a single sample prep aration and HPLC run for each sample. The recovery from fortified samples w as greater than 95% over the concentration range 5-2000 ng/g wet weight fec es.