Capillary zone electrophoresis for the analysis of phthalate-derivatized hydroxyl- and amino-containing compounds

Various non UV-active hydroxylated and amino-containing (monomers and polym ers) compounds were derivatized with phthalic anhydride (pre- or in-column) to allow CZE-diode array detection analysis. The derivatization procedure, using imidazole and pyridine to catalyze phthalation, leads to fast and co mplete derivatization. The alcohols are UV-inactive and are not charged. Th e amines can be charged, but they also lack UV-sensitivity. The result of p hthalation is the insertion of a chromophore (phenyl group) and an ionic fu nctionality (carboxyl) into the compounds under investigation. In this mann er, using pre-column derivatization, it is possible to separate mixtures of monomeric alcohols and amines. Due to the high efficiency, inherent to CE, it is also possible, on the basis of the difference in electrophoretic mob ilities, to investigate the distribution in the chain length of synthetic p oly(ethylene glycol) and poly(oxyalkylene)amine polymers. A successful atte mpt was made to use in-column derivatization for the analysis of the amino- containing monomers and polymers. Analyses were performed on bare fused sil ica, as well as on wall coated capillaries.