Potassium clavulanate was recovered by ion exchange chromatography from model clavulanate solutions with amoxicillin, a β-lactam antibiotic as the major impurity, simulating fermentation broth. A strong anion exchanger, Amberlite IRA400 resin was used. The effects of pH on the chemical stability of potassium clavulanate was investigated to find that when the pH was 5.0 or over clavulanate was very stable. The effects of washing buffer pH and concentration, elution mode (isocratic or gradient), and eluent concentration and flow rate were also investigated. A buffer pH of 5 was more advantageous than pH 6 for the removal of amoxicillin. The buffer concentration had no significant effects on the removal of amoxicillin. The recovery rate increased with the eluent concentration and flow rate. Under the optimal conditions, over 99% of amoxicillin was removed and over 99% of potassium clavulanate was recovered. In the subsequent step of electrolysis to remove KCl that existed in a large amount in the eluted solution, the effects of chloride and clavulanate concentrations were investigated. The concentration of chloride had a positive effect on the recovery of clavulanate and on the purity. The recovery rate of clavulanate increased with the clavulanate concentration. Under the optimal conditions, the final purity was over 96%.
