Capillary isotachophoretic analysis of β-lactam antibiotics and their precursors

An analytical capillary isotachophoretic method has been developed for the qualitative and quantitative analysis of β-lactam antibiotics, i.e. penicillins and cephalosporins, in chemical and pharmaceutical preparations. This technique also permits the quantitative assay of the β-lactam antibiotics precursors 6-aminopenicillanic acid and 7-aminocephalosporanic acid which are the key materials for the industrial production of semisynthetic penicillins and cephalosporins. Two different electrolyte systems were employed with pH values of the leading electrolytes of 4 and 7. The use of a leading electrolyte with a pH of 7.0 allows the sensitive detection of several β-lactam antibiotics independent of the chemical structure of the sidechain of the penicillin or cephalosporin nucleus. Capillary isotachophoresis is an excellent analytical tool for quality control of β-lactam antibiotics such as penicillins and cephalosporins.