Prev. Article Next Article Table of Contents

Article

Calculationg Microspecies Concentration of Zwitterion Amphoteric Compounds: Ciprofloxacin as Example

Your current credentials do not allow retrieval of the full text.

Purchase the full-text

PDF/HTML,
figures/images,
references and tables,
(where available)

Jordi Hernàndez-Borrell and M. Teresa Montero

Universitat de Barcelona, Unitat de FisicoquÃmica, Faculatat de Farmàcia, 08028, Barcelona, Spain

J. Chem. Educ., 1997, 74 (11), p 1311

DOI: 10.1021/ed074p1311

Publication Date (Web): November 1, 1997

Section:

History, Education, and Documentation

Abstract

In this paper we describe a method normally used for calculating microspecies concentration of zwitterion amphoteric compounds. Dissociation constants at microscopic level are frequently ignored in general textbooks of physical chemistry or only introduced when amino acid or nucleic acid are of particular interest. Therefore a detailed theoretical description is presented in the paper together with the experimental section. A combination of basic spectrophotometric and potentiometric methods enable students the calculation of the total concentration of each microspecies. To emphasize the interest of microspeciation in the biochemical and biological fields the antimicrobial drug ciprofloxacin was selected as example. The experiment can be extended to other active compounds as cephalosporins or pyridoxine and the relation of this phenomena with the pharmacological activity of drugs discussed in the classroom.