The retention behavior of several semisynthetic cephalosporins in planar chromatography

Abstract

The chromatographic behavior of cephalexine, cefaclore, ceftriaxone, cefiuime, and cefotaxime has been investigated on silica gel layers with binary mobile phases containing different amounts of organic modifier. The influence of type, chemical character, and position of substitution of functional groups (steric and structural effects) on the retention of analyzed compounds was of particular interest. Systematic investigation of the cephalosporins furnished much information about their hydrophobicity (R-M(0)), the mechanism of adsorption, and the possibilities of separation. Correlation of the hydrophobicity parameters R-M(0), m, and C-0 with the lipophilicity parameter log P was established by use of linear equations. The parameter C-0 was considered as directly applicable in quantitative structure-activity relationships of the cephalosporins.