CAPILLARY ELECTROPHORETIC STUDY OF DIBASIC ACIDS OF DIFFERENT STRUCTURES - RELATION TO SEPARATION OF OXIDATIVE INTERMEDIATES IN REMEDIATION

Dicarboxylic acids are important in environmental chemistry because th ey are intermediates in oxidative processes involved in natural remedi ation and waste management processes such as oxidative detoxification and advanced oxidation. Capillary electrophoresis (CE), a promising te chnique for separating and analyzing these intermediates, has been use d to examine a series of dibasic acids of different structures and con formations. This series includes malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, phthalic acid, and trans, trans-muconic acid. The CE parameters as well as stru ctural variations (molecular structure and molecular isomers, buffer c omposition, pH, applied voltage, injection mode, current, temperature, and detection wavelength) that affect the separations and analytical results have been examined in this study. Those factors that affect th e separation have been delineated. Among these parameters, the pH has been found to be the most important, which affects the double-layer of the capillary wall, the electro-osmotic flow and analyte mobility. Th e optimum pH for separating these dibasic acids, as well as the other parameters are discussed in detail and related to the development of m ethods for analyzing oxidation intermediates in oxidative waste manage ment procedures. (C) 1998 Elsevier Science Ltd. All rights reserved.