Capillary zone electrophoresis was applied to the analysis of N-benzyl
-N-alkyl-N,N-dimethylammonium chloride compounds with different alkyl
chain lengths (C-12-C-18) by direct UV detection. A tetrahydrofuran-co
ntaining buffer was used to prevent the occurrence of micellization an
d adsorption of the surfactants, thereby yielding adequate separations
according to their free-form electrophoretic mobilities. Resolution,
theoretical plate number, reproducibility and precision were ascertain
ed. Finally, the electrophoretic method was applied to the qualitative
and quantitative determination of an industrial mixture of C-n-benzyl
surfactants.