Utilization of Ion-Exclusion Chromatography for the Quality Test of Water Purifications of Photocatalytic Environmental Materials

A quality test for water purification of TiO2-photocatalyst coated materials (photocatalytic materials) has been observed using ion-exclusion chromatographic methods. Ion-exclusion chromatography has been used to decrease the carboxylate ion and the formation of its products in photooxidation process of a carboxylic acid, e.g., propionic or butyric acids, on the time-dependency of UV irradiation. Ion-exclusion/cation-exchange chromatography has been used to determine relationships between the decrease of an aliphatic amine and the formation of ammonium and nitrate ions. In a quality test standardized in Japan, dimethylsulfoxide (DMSO) was adopted as the starting sample because of stoichiometric oxidation with an OH radical generated from TiO2. A fundamental study on the photodegradation of DMSO was provided by ion-exclusion/adsorption chromatography. Also, in this paper, ion-exclusion chromatographic methods with post-column reactions are described for the detections of aliphatic carboxylate, carbonate, phosphate, and silicate ions in quality tests for photocatalytic materials.