Micellar electrokinetic capillary chromatography analysis of phthalic acid isomers.

A capillary electrophoretic method for the analysis and separation of ortho- and para-phthalic acid isomers was developed. The best separation was achieved using micellar electrokinetic capillary chromatography (MECC) performed in a 110 mM borate buffer pH 8.3 also containing 40 mM sodium dodecyl sulfate (SDS) and 20% methanol. The effect of the addition of methanol, acetonitrile, and beta-cyclodextrin on the separation of the isomers was investigated. The buffer system developed was shown to provide a dependable method of analysis from which the concentration of each analyte could be reliably determined.