title: Study on the generation mechanism of reactive oxygen species on calcium peroxide by chemiluminescence and UV-visible spectra.
abstract: In the present work, the generation mechanism of reactive oxygen species (ROS) on calcium peroxide (CaO(2)) was studied. A very intense chemiluminescence (CL) signal was observed when adding an aqueous solution of luminol or 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2alpha]-pyrazin-3-one hydrochloride (MCLA) to a suspension of CaO(2). The ROS released on CaO(2) were thought to be oxidizing agents leading to CL, and were characterized by CL, UV-visible (UV-vis) spectra and the effective scavengers of the special ROS. From experimental results, the hydroxyl (.OH) and superoxide (.O(2) (-)) radicals were suggested to exist on the surface of CaO(2). A reaction scheme for the formation of the ROS on CaO(2) was also proposed and discussed. Of more interest was the finding that the CaO(2) which released the .OH and .O(2) (-) on the surface exhibited good transition properties compared with alkaline-earth metal peroxides of the same group (MgO(2), BaO(2)).
authors.affiliation: College of Science, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Ma
authors.forename: Bo-Tao
authors.initials: BT
authors.lastname: Zhang
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhao
authors.forename: Guangsheng
authors.initials: G
authors.lastname: Guo
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
mesh_terms: D016166:Free Radical Scavengers / Q000737:chemistry / Q000378:metabolism; D017665:Hydroxyl Radical / Q000737:chemistry / Q000378:metabolism; D007093:Imidazoles / Q000737:chemistry; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol / Q000737:chemistry; D008673:Metals, Alkaline Earth / Q000737:chemistry / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D010545:Peroxides / Q000737:chemistry / Q000378:metabolism*; D011719:Pyrazines / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism*; D012996:Solutions / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D016166:Free Radical Scavengers; D007093:Imidazoles; D008673:Metals, Alkaline Earth; D010545:Peroxides; D011719:Pyrazines; D017382:Reactive Oxygen Species; D012996:Solutions; D014867:Water; C063412:2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo(1,2-alpha)pyrazin-3-one; D017665:Hydroxyl Radical; D008165:Luminol; C403632:calcium peroxide; D010100:Oxygen