Photosensitized degradation of Irgarol 1051 in water.
Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) is a herbicide analogue that is added to antifouling agents used on ships. Our former study on its degradation in sunlight suggested that unknown photosensitizers in natural waters accelerated the photodegradation to the degradation product, M1. In this study, the photodegradation of Irgarol in water was investigated in the presence of some photosensitizers. Test water containing Irgarol or M1, with or without photosensitizers, was irradiated with light from a UV-A fluorescent lamp for 48h. The concentrations of Irgarol and M1 in the test water were determined by HPLC after solid-phase extraction. M1 was more stable than Irgarol when irradiated in the presence of photosensitizers such as acetone, benzophenone, tryptophan, and rose bengal. Hydrogen peroxide (HP) accelerated the photodegradation of Irgarol, and the product M1 was degraded in the presence of more than 100mgl(-1) HP after 10h. Natural humic substances (NHS) also accelerated the photodegradation of Irgarol, but in this case, the product M1 persisted even when Irgarol was completely degraded. Photosensitized degradation of Irgarol by NHS may result in the accumulation of M1 in aquatic environments.
Faculty of Maritime Sciences, Kobe University, Fukaeminami 5-1-1 Higashinada, Kobe 658-0022, Japan. okamurah@maritime.kobe-u.ac.jp
Hideo
H
Okamura
Yuko
Y
Sugiyama
D000096:Acetone; D001577:Benzophenones; D002851:Chromatography, High Pressure Liquid; D006861:Hydrogen Peroxide / Q000737:chemistry; D007700:Kinetics; D010782:Photolysis; D017319:Photosensitizing Agents / Q000737:chemistry*; D012395:Rose Bengal; D014227:Triazines / Q000737:chemistry*; D014364:Tryptophan; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry
D001577:Benzophenones; D017319:Photosensitizing Agents; D014227:Triazines; D014867:Water; D000096:Acetone; D012395:Rose Bengal; C103341:irgarol 1051; C047723:benzophenone; D014364:Tryptophan; D006861:Hydrogen Peroxide