MATRIX SOLID-PHASE DISPERSION TECHNIQUE FOR THE DETERMINATION OF MOXIDECTIN IN BOVINE-TISSUES

An HPLC method has been developed for the determination of moxidectin in bovine tissues, The extraction and clean-up procedure is based on t he matrix solid-phase dispersion technique. Control and moxidectin-for tified bovine tissue samples (0.25 g) are blended with octadecyl (C-18 end-capped) packing material. A column made from the C-18-bovine tiss ue blend is mashed with hexane (2 ml); when all the hexane has eluted, an Alumina-B SPE cartridge is attached below the C-18-tissue column a nd, after washing, moxidectin is eluted with methanol (6 ml). Moxidect in is derivatized and determined by HPLC with fluorescence detection, The recovery from fortified samples was greater than 80% in the concen tration range 1-100 ng g(-1) of tissue, This method permits the determ ination of moxidectin at levels as low as 1 ng g(-1) (1 ppb).