Derivative spectrophotometric determination of the triethylammonium salt of cefotaxime in presence of related compounds from the synthesis

Cefotaxime sodium is a broad spectrum third generation antibiotic. It is obtained by reaction of 7-aminocephalosporanic acid (7-ACA) and S-(2-benzothiazolyl)2-amino-alpha-(methoxyimino)-4-thiazoleethaanethioate. 2-Mercaptobenzothiazole is a by-product of this reaction. A derivative spectro;photometric determination of cefotaxime is proposed for its determination in a reaction mixture in the presence of the related compounds from synthesis. With this method Beer's law is obeyed over a concentration range from 0.005 to 0.080 mg ml(-1) at 276.8 nm (r = 0.9995). This technique is accurate, precise (RSD = 0.4%), and has a sensitivity of 1.2% (differences in analytical response of 0.74 mu g ml(-1) could be detected). Recovery experiments of cefotaxime from reaction mixtures include 100% for all assayed concentrations. For these reasons, this technique is found valid for the intended purposes. (C) 1998 Elsevier Science B.V. All rights reserved.