Shigeaki Kitabayashi

Applicability of MCM-41 as column packing in HPLC for the evaluation of aluminum species in partially neutralized aluminum solutions

Abstract Separation of Al ionic species in partially neutralized aluminum solution was studied using HPLC technique in order to elucidate the applicability of MCM-41 as promising column packing. Three peaks observed in HPCL chromatogram were assigned to mononuclear aluminum cation (Al(mono)), tridecameric polycation (Al(13)), and polynuclear precursors of Al(OH) 3 (Al(poly)) in the order of appearance. Overlapping of the peaks between Al(mono) and Al(13) was significant, however, these three Al species were quantitatively evaluated by using a curve fitting. A plausible mechanism for the present system does not obey the gel permeation chromatography principle, but it is suggested that the separation of Al species in the present system proceeds through the chemical interactions between the Al species and the surface of MCM-41. The structural changes in MCM-41 were observed due to the hydrolysis of silica framework of MCM-41 and the pressure during the HPLC operations.