MULTIRESIDUE ANALYSIS OF TETRACYCLINES IN KIDNEY BY HPLC AND PHOTODIODE-ARRAY DETECTION

The method describes the analysis of six tetracyclines at a low residue level by HPLC. The tetracyclines were extracted from kidney by a succinate buffer, for their purification Chelating Sepharose and Bond Elut C-18 columns were used successively. The samples were analyzed on a liquid chromatograph fitted with two Chromspher C-8 columns and a photodiode array detector. The quantification limits are 10 or 30 mug/kg kidney depending on the kind of tetracyclines, the absolute detection limits are 4 or 12 ng respectively. The method has already been used for routine analysis. All positive samples were confirmed by comparing the spectrum of the unknown peak, supposed to be a tetracycline, with the spectrum of the corresponding standard.