Abstract
Microbonded propylamine silica with a solvent system containing acetic acid, methanol, acetonitrile and water (2:4:7.5:86.5) is suitable for an efficient separation of mixtures containing several closely related cephem derivatives. The same system with preparative columns was used for the isolation of cephalosporin C directly from the filtered broth of Cephalosporium acremonium fermentation.