DEVELOPMENT OF MULTI-RESIDUE METHODOLOGY FOR THE HPLC DETERMINATION OF VETERINARY DRUGS IN ANIMAL-TISSUES

The application of solid-phase extraction and HPLC with UV-diode array detection to the multi-residue determination of veterinary drugs is d escribed. A two-stage SPE clean-up was employed, using C18 and silica cartridges. HPLC analysis was carried out on a base-deactivated C8 col umn using gradient elution systems at two pH values. The procedure est ablishes the basis of a method for routine screening of pig kidney sam ples for some sulphonamides, benzimidazoles, nitroimidazoles and nitro furans at concentrations at or below the UK Maximum Residue Limits (MR Ls). Limits of detection of 2-18 mu g/kg could be achieved for these a nalytes at recoveries of 40-70%. UV spectra measured on-line were used for confirmation of peak identities at these concentrations. The poss ibility of extension of this procedure to a wider range of analytes is discussed.