Reza Hosseinzadeh,* Ramin Maleki, Amir Abbas Matin

Food and Chemical Analysis Research Laboratory, Jahad-e-Daneshgahi, Urmia University, Urmia, Iran.
Fax: +984413445410,
E-mail: chem.reza@gmail.com or r.hoseinzadeh@acecr.ac.ir.

Abstract
The binding of sodium diclofenac (SD) with bovine serum albumin (BSA) has been extensively studied at various concentration of BSA, using diclofenac-selective membrane electrodes constructed in our laboratory. The accurate binding isotherms have been obtained and analyzed in terms of binding capacity concept. The results represent two binding set system for all of studied conditions. The values of Hill equation parameters have been estimated and used for calculation of intrinsic Gibbs free energy of binding.

Keywords: Diclofenac sodium, bovine serum albumin, binding isotherm, binding capacity, diclofenac-selective electrode, Gibbs free energy.