Investigation of new chelation ion chromatography procedure to determine the surface composition of powdered metal oxide samples in the solid state

Numerous tests have been conducted on the feasibility of characterizing the surfaces of metal oxide powders using HPLC. An in-line filter housing was modified to serve as a sample chamber to replace the sample loop. A gradient pump was used to gradually increase eluent acidity to find the conditions at which the surface of a metal oxide powder began to dissolve. The theoretical masses of surface monolayers of metal oxide powders were compared with the experimentally determined masses of dissolved material thought to be from the surface to test whether surface and bulk dissolution phenomena in acidic conditions are separable and quantifiable. A set of methods was tested that could first dissolve a metal oxide sample’s surface, then separate and detect analyte species by chelation ion chromatography. Surface characterization by ion chromatography could be more cost-effective than existing methods, and reveal chemical properties of the sample where existing methods only give physical composition and properties.