title: Photocatalytic decomposition behavior and reaction pathway of sulfamethazine antibiotic using TiO2.
abstract: The photocatalytic degradation of sulfanethazine (SMT), one of the sulfonamide antibiotics, in aqueous solution by TiO2 was investigated. The time courses of SMT concentration, the amount of non-purgeable organic carbon, and the concentrations of ions such as SO4(2-), NH4(+), and NO3(-) formed during the photocatalytic reaction were measured and the structures of seven intermediates formed with the disappearance of SMT were also estimated by LC/MS/MS analyses. In addition to that of SMT, the decomposition behaviors of model compounds sulfanilic acid (SA) and 4-amino-2, 6-dimethylpyrimidine (ADMP) were investigated using the TiO2/UV system. The observed photocatalytic degradation behaviors of SMT, SA, and ADMP gave new insight into the degradation pathway of SMT. Especially, the formation of p-aminophenol during SMT decomposition, which until now has not been reported in previous studies concerning the photocatalytic decomposition of SMT and other sulfonamide antibiotics. These results indicate the existence of a novel photocatalytic degradation pathway for sulfonamides. The direct substitution of the sulfonamide group with a hydroxyl group is suggested.
authors.affiliation: Center for Paper Industry Innovation, Ehime University, 127 Mendoricho Otsu, Shikokuchuo, Ehime 799-0113, Japan; Japan Science and Technology Agency, CREST, Japan. Electronic address: fukahori.shuji.mj@ehime-u.ac.jp.
authors.forename: Shuji
authors.initials: S
authors.lastname: Fukahori
authors.affiliation: Research and Education Faculty, Natural Sciences Cluster, Agriculture Unit, Kochi University, 200 Monobe Otsu, Nankoku, Kochi 783-8502, Japan; Japan Science and Technology Agency, CREST, Japan. Electronic address: fujiwarat@kochi-u.ac.jp.
authors.forename: Taku
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002384:Catalysis; D006801:Humans; D013418:Sulfamethazine / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D013418:Sulfamethazine; D014025:Titanium
keywords: Antibiotics; Intermediate product; Photocatalytic decomposition; Sulfonamide; TiO(2)