Alkalimetric microassay of cephalosporins.

Abstract
Alkalimetric pH-stat titrations of cephalosporin C, cephacetril and their deacetyl derivatives using an acetyl esterase and .beta.-lactamase are described. The esterase was used to assay highly purified samples of cephalosporin C and cephacetril and also to prepare analytically defined solutions of the deacetyl cephalosporins. Lactamase-catalyzed hydrolysis of the parent compounds generated exactly 2 equivalents of acid/mol; that of the deacetyl derivatives exactly 1 equivalent.