ANALYSIS OF THE COMPOSITION OF MASKED ALUMINUM COMPLEXES BY HPLC COMBINED WITH CAPILLARY ELECTROPHORESIS

Size-exclusion, high performance liquid chromatography (HPLC) combined with capillary electrophoresis was applied to analyze the composition of oxycarboxylate-masked aluminum complexes. Using a HPLC column (Asa hipak GS-220) connected to a refractive index detector, oxycarboxylate -masked aluminum complexes were separated into several peak fractions. Oxy-acid content of the fractions was successfully determined by capi llary electrophoresis (Shimadzu IP-2A). Glycolate- and lactate-masked aluminum complexes contained the major portion of the components to be eluted in the lower molecular size region while a considerable portio n of tartrate- and citrate-masked complexes eluted in the higher molec ular size region. All masked-aluminum fractions contained oxy-acids at an equivalent-to-mole of Al ratio of 0.1 to 0.2.