THE ANALYSIS OF AMINOGLYCOSIDE ANTIBIOTICS BY CAPILLARY ELECTROPHORESIS

The analyses of aminoglycoside antibiotics by capillary electrophoresi s utilizing berate complexation and direct UV detection are discussed. Twelve aminoglycosides were studied and separated to demonstrate iden tification capabilities, with migration time RSDs from 0.21 to 0.44% ( n = 6) for individual components. This buffer system permitted the det ection of minor impurities such as precursors; or closely related ferm entation products. Quantification of dihydrostreptomycin and streptomy cin was accomplished in 160 mM sodium tetraborate decahydrate with lin earity over the range 0.050-1.0 mg ml(-1). Determination of the purity of bulk dihydrostreptomycin was possible by the addition of the catio nic surfactant myristyltrimethylammonium bromide. This reversed the el ectroosmotic flow, thereby reversing the migration order, and causing the streptomycin impurity to migrate before the dihydrostreptomycin ma in peak. Quantification was also demonstrated with the closely related compounds amikacin, bekanamycin, kanamycin A, and tobramycin, using s isomicin as an internal standard. The reproducibility of the method wa s typically 2-3% over 1 day, and 2% day-to-day. These studies illustra te the use of capillary electrophoresis for the identification and qua ntification of selected aminoglycosides as potential alternative metho ds to the assays given by the US Pharmacopeia.