title: Decomposition reaction of the veterinary antibiotic ciprofloxacin using electron ionizing energy.
abstract: The application of electron ionizing energy for degrading veterinary antibiotic ciprofloxacin (CFX) in aqueous solution was elucidated. The degradation efficiency of CFX after irradiation with electron ionizing energy was 38% at 1 kGy, 80% at 5kGy, and 97% at 10 kGy. Total organic carbon of CFX in aqueous solution after irradiation with electron ionizing energy decreased 2% at 1 kGy, 18% at 5 kGy, and 53% at 10 kGy. The CFX degradation products after irradiation with electron ionizing energy were CFX1 ([M+H] m/z 330), CFX2 ([M+H] m/z 314), and CFX3 ([M+H] m/z 263). CFX1 had an F atom substituted with OH and CFX2 was expected to originate from CFX via loss of F or H2O. CFX3 was expected to originate from CFX via loss of the piperazynilic ring. Among the several radicals, hydrate electron (eaq(-)) is expected to play an important role in degradation of veterinary antibiotic during irradiation with electron ionizing energy. The toxicity of the degraded products formed during irradiation with electron ionizing energy was evaluated using microbes such as Escherichia coli, Pseudomonas putida, and Bacillus subtilis, and the results revealed that the toxicity decreased with irradiation. These results demonstrate that irradiation technology using electron ionizing energy is an effective was to remove veterinary antibiotics from an aquatic ecosystem.
authors.affiliation: Department of Bioenvironmental Chemistry, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Cho
authors.affiliation: Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute (KAERI), Jeongeup 580-185, Republic of Korea.
authors.forename: Byung Yeoup
authors.initials: BY
authors.lastname: Chung
authors.affiliation: Planning and Coordination Div., National Institute of Crop Science, Rural Development Administration, Suwon 441-857, Republic of Korea.
authors.forename: Kyeong-Bo
authors.initials: KB
authors.lastname: Lee
authors.affiliation: Department of Rice and Winter Cereal Crop, National Institute of Crop Science, Rural Development Administration, Iksan 570-080, Republic of Korea.
authors.forename: Geon-Hwi
authors.initials: GH
authors.lastname: Lee
authors.affiliation: Department of Rice and Winter Cereal Crop, National Institute of Crop Science, Rural Development Administration, Iksan 570-080, Republic of Korea. Electronic address: hsa9697h@jbnu.ac.kr.
authors.forename: Seon Ah
authors.initials: SA
authors.lastname: Hwang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000528:radiation effects*; D001412:Bacillus subtilis / Q000187:drug effects; D002939:Ciprofloxacin / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects*; D004583:Electrons; D004926:Escherichia coli / Q000187:drug effects; D010782:Photolysis; D016958:Pseudomonas putida / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects*
chemical_list: D000900:Anti-Bacterial Agents; D014874:Water Pollutants, Chemical; D002939:Ciprofloxacin
keywords: Ciprofloxacin; Decomposition; Electron ionizing energy; Veterinary antibiotic