Table of Contents
Chromatography Research International
Volume 2012, Article ID 458153, 6 pages
http://dx.doi.org/10.1155/2012/458153
Research Article

Selectivity of Brij-35 in Micellar Liquid Chromatographic Separation of Positional Isomers

National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Sindh 78060, Pakistan

Received 19 September 2011; Revised 31 October 2011; Accepted 14 November 2011

Academic Editor: Maria Jose Ruiz-Angel

Copyright © 2012 Najma Memon et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Implementation of Brij-35, a nonionic surfactant, as a mobile phase for separation of positional isomers is investigated. Chromolith C-18 SpeedROD is used as a stationary phase. The effect of surfactant and organic modifier (propanol) concentration on the separation of some selected isomers is studied and evaluated in terms of linear solvation energy relationship (LSER). Shape selectivity is assessed by α value of sorbic and benzoic acid, which is found to be 1.339 by using mobile phase composed of 0.5% aqueous solutions of Brij-35 and propanol in 9 : 1. Isomers of parabens, nitroanilines, nitrophenols, and quinolinols are successfully separated using mobile phases composed of various percentages of surfactant and propanol. System constants for nonionic MLC using LSER analysis show that hydrogen bond basicity and dipolarity may be major contributors to selectivity, while excess molar refraction helps fine-tuning the separation which also imparts unique selectivity to nonionic surfactants as compared to ionic ones.