The effect of Cu2+ chelation on the direct photolysis of oxytetracycline: A study assisted by spectroscopy analysis and DFT calculation

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境化学与生态毒理学国家重点实验室

	The effect of Cu2+ chelation on the direct photolysis of oxytetracycline: A study assisted by spectroscopy analysis and DFT calculation
	Jin, Xin; Qiu, Shanshan; Wu, Ke; Jia, Mingyun; Wang, Fang; Gu, Chenggang; Zhang, Aigian; Jiang, Xin
刊名	ENVIRONMENTAL POLLUTION
	2016-07
卷号	214 期号:0 页码:831-839
关键词	Oxytetracycline Cu2+ Chelation Direct photolysis TD-DFT
英文摘要	The extensive usage of OTC and Cu2+ in livestock and poultry industry caused high residues in natural environment. Co-contamination of OTC and Cu2+ was a considerable environmental problem in surface waters. In this study, Cu2+ mediated direct photolysis of OTC was studied. Cu2+ chelating with OTC was found to greatly inhibit OTC photodegradation. To reveal the chelation mechanism of OTC-Cu complexes, multiple methods including UV-Vis absorption spectra, Infrared (IR) spectra, mass spectroscopy, and density functional theoretical (DFT) modeling were performed. Four OTC-Cu complexes were proposed. Cu2+ preferably bond to O-11-O-12 site with the binding constants logK = 8.19 and 7.86 for CuHL+ and CuL +/-, respectively. The second chelating site was suggested to be O2-O3 with the binding constants of logK = 4.41 and 4.62 for Cu2HL3+ and Cu2L(2+), respectively. The suppressed quantum yield of OTC by Cu2+ chelation was accused for their intra-/inter-molecular electron transfer, by which the energy in activated states was distributed. The occurrence of electron transfer between BCD ring and A ring also from BCD ring to Cu was evidenced by the TD-DFT result only for the OTC-Cu complexes. Besides, the cyclic voltammetry measurement also suggested one OTC-Cu(II)/OTC-Cu(I) redox couple. These results suggested that the persistence of OTC in environmental surface waters will probably be underestimated for neglecting the chelating effect of Cu2+. The photolysis quantum yield of OTC-Cu complexes, as well as the specific molar absorption constants, the equilibrium binding constants of Cu2+ with OTC could contribute to more accurate kinetic models of OTC. (C) 2016 Elsevier Ltd. All rights reserved.
收录类别	SCI
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/35958]
专题	生态环境研究中心_环境化学与生态毒理学国家重点实验室
推荐引用方式 GB/T 7714	Jin, Xin,Qiu, Shanshan,Wu, Ke,et al. The effect of Cu2+ chelation on the direct photolysis of oxytetracycline: A study assisted by spectroscopy analysis and DFT calculation[J]. ENVIRONMENTAL POLLUTION,2016,214(0):831-839.
APA	Jin, Xin.,Qiu, Shanshan.,Wu, Ke.,Jia, Mingyun.,Wang, Fang.,...&Jiang, Xin.(2016).The effect of Cu2+ chelation on the direct photolysis of oxytetracycline: A study assisted by spectroscopy analysis and DFT calculation.ENVIRONMENTAL POLLUTION,214(0),831-839.
MLA	Jin, Xin,et al."The effect of Cu2+ chelation on the direct photolysis of oxytetracycline: A study assisted by spectroscopy analysis and DFT calculation".ENVIRONMENTAL POLLUTION 214.0(2016):831-839.