QUANTITATIVE-DETERMINATION OF ERYTHROMYCIN AND ITS HYDROLYSIS PRODUCTS BY CYCLIC VOLTAMMETRY AT THE INTERFACE BETWEEN WATER AND 1,2-DICHLOROETHANE

An electrochemical method for quantifying erythromycin (Er) salts and their hydrolysis products is described. Cyclic voltammetry at the wate r/1,2-dichloroethane interface in a four-electrode system was used. A linear relationship between I(p) and the erythromycin concentration wa s obtained up to the solubility limit of the antibiotic. The various h ydrolysis products which can be obtained in acid or basic solutions we re characterized by their respective transfer potentials. Similar hydr olysis products were observed for aged solutions of Er lactobionate. I t is concluded that the proposed method is suitable for the quantifica tion of Er and for distinguishing it from its hydrolysis products.