AUTOMATED COLUMN LIQUID-CHROMATOGRAPHIC DETERMINATION OF AMOXICILLIN AND CEFADROXIL IN BOVINE SERUM AND MUSCLE-TISSUE USING ONLINE DIALYSISFOR SAMPLE PREPARATION

A fully automated method is described for the determination of amoxici llin and cefadroxil in bovine serum and muscle tissue. The method is b ased on the on-line combination of dialysis and solid-phase extraction for sample preparation, and column liquid chromatography with ultravi olet detection. In order to enhance the UV detectability of the analyt es, post-column addition of 0.1 M sodium hydroxide is performed. The m ethod shows good linearity and repeatability for both analytes in seru m as well as in muscle tissue; the limits of detection in these sample s are 0.05 mu g/ml and 0.2 mu g/g, respectively. The method has a samp le throughput of 30 samples per 24 h.