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Mortensen N, Toews P, Bates J. Crosslinking-Dependent Drug Kinetics in Hydrogels for Ophthalmic Delivery. Polymers (Basel) 2022; 14:248. [PMID: 35054655 PMCID: PMC8779755 DOI: 10.3390/polym14020248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/05/2022] [Accepted: 01/05/2022] [Indexed: 02/01/2023] Open
Abstract
Drug-diffusion kinetics in 2-hydroxyethyl methacrylate hydrogels were studied as a function of the crosslinking density and porosity. By varying the concentration of the crosslinker, tetraethylene glycol dimethacrylate, we demonstrated how the release of Timolol maleate could be optimized to allow for efficient drug delivery. FTIR and spectrophotometry supplied optical inferences into the functional groups present. By studying the swelling and degradation of hydrogels, supplemented with drug-release kinetics studies, the relationship between these two tenets could be formulated.
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Affiliation(s)
| | | | - Jeffrey Bates
- Department of Materials Science and Engineering, University of Utah, 122 Central Campus Drive, Room 304, Salt Lake City, UT 84112, USA; (N.M.); (P.T.)
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2
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Wang J, Wang K, Zhang L, Guo Y, Guo Z, Sun W, Ye Z, Niu J. Mechanism of bicarbonate enhancing the photodegradation of β-blockers in natural waters. WATER RESEARCH 2021; 197:117078. [PMID: 33819659 DOI: 10.1016/j.watres.2021.117078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 06/12/2023]
Abstract
The impact of HCO3- on the photodegradation of β-blockers was investigated under simulated sunlight irradiation. The results show that in the presence of HCO3-, the photodegradation rates increase significantly for sotalol (SOT), whereas no effects on the degradation of carvedilol and arotinolol are observed. Using quenching experiments, electron paramagnetic resonance spectra and degradation product determination, we demonstrate that carbonate radical (CO3•-) is formed by direct oxidation of HCO3- by triplet-excited SOT (3SOT*) and plays a significant role in SOT photodegradation. Competition kinetics experiments show that the three β-blockers all have high second-order rate constants (107-108 M-1 s-1) for the reaction with CO3•-. However, only 3SOT* has a higher reduction potential that can oxidize HCO3- to produce CO3•-. Thus, enhanced SOT removal rates in the presence of HCO3- were observed. In addition, the results show that seawater DOM could increase HCO3--induced photodegradation of SOT, whereas SRNOM mainly behaves as a CO3•- quencher and decreases the removal rate of SOT. The results underscore the role of HCO3- in limiting the persistence of organic pollutants like SOT in sunlit natural waters, and especially in marine and coastal waters.
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Affiliation(s)
- Jieqiong Wang
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Kai Wang
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Lilan Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Yuchen Guo
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Zhongyu Guo
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8552, Japan
| | - Wei Sun
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Zimi Ye
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Junfeng Niu
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China.
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3
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Chen XM, Chu YJ, Liu CG. Degradation Mechanism of Benzo[ a]pyrene Initiated by the OH Radical and 1O 2: An Insight from Density Functional Theory Calculations. ACS OMEGA 2020; 5:25552-25560. [PMID: 33073081 PMCID: PMC7557245 DOI: 10.1021/acsomega.0c01448] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
The degradation mechanism of benzo[a]pyrene (BaP) initiated by •OH and 1O2 in aqueous solution is investigated by density functional theory calculations. The main degradation products are BaP-1,6-quinone, BaP-3,6-quinone, BaP-4,6-quinone, and BaP-6,12-quinone. •OH and HO2 are the main intermediate radical species. At a low initial concentration of •OH, 1O2 could be a primary driver for BaP degradation. The degradation mechanism includes six consecutive elementary reactions: (1) 1O2 initiation forming BaP-6-OO. (2) 1,3 H-shift (H atom shifts to the OO group) that is promoted by H2O, forming BaP-6-OOH. (3) BaP-6-OOH decomposes into the •OH radical and BaP-6-O. (4) •OH addition to BaP-6-O forming BaP-6-O-1(3,4,12)-OH. (5) Extracting the H atom from the carbon with the OH group by 1O2. (6) Extracting the H atom from the OH group by HO2. At a high initial concentration of •OH, the •OH-initiated and 1O2-initiated degradation reactions of BaP are both feasible. The degradation mechanism includes six consecutive elementary reactions: (1) •OH initiation forming BaP-6-OH or 1O2 initiation forming BaP-6-OO. (2) 1O2 addition to BaP-6-OH forming BaP-6-OH-12(1,3,4)-OO or •OH addition to BaP-6-OO forming BaP-6-OO-12(1,3,4)-OH. (3) Extracting the H atom from the carbon with the OH group by 1O2, forming HO2. (4) 1,3 H-shift (H-shift from the carbon to the OO group), promoted by H2O. (5) The loss of the OH radical. (6) Abstracting the H atom from the OH group by HO2. In this paper, the formation of BaP-4,6-quinone via the BaP degradation is first reported. Water participates in the elementary reaction in which the H atom attached on the aromatic ring shifts to the OO group, serving as a bridge that stabilizes the transition state and transports the proton. A comprehensive investigation explains the degradation mechanism of BaP initiated by •OH and 1O2 in aqueous solution.
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Affiliation(s)
- Xue-Mei Chen
- College
of Chemical Engineering, Northeast Electric
Power University, Jilin
City 132012, China
| | - Yun-Jie Chu
- College
of Chemical Engineering, Northeast Electric
Power University, Jilin
City 132012, China
| | - Chun-Guang Liu
- Department
of Chemistry, Faculty of Science, Beihua
University, Jilin
City 132013, China
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4
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Zhang K, Parker KM. Halogen Radical Oxidants in Natural and Engineered Aquatic Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9579-9594. [PMID: 30080407 DOI: 10.1021/acs.est.8b02219] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Photochemical reactions contribute to the transformation of contaminants and biogeochemically important substrates in environmental aquatic systems. Recent research has demonstrated that halogen radicals (e.g., Cl•, Br•, Cl2•-, BrCl•-, Br2•-) impact photochemical processes in sunlit estuarine and coastal waters rich in halides (e.g., chloride, Cl-, and bromide, Br-). In addition, halogen radicals participate in contaminant degradation in some engineered processes, including chlorine photolysis for drinking water treatment and several radical-based processes for brine and wastewater treatment. Halogen radicals react selectively with substrates (with bimolecular rate constants spanning several orders of magnitude) and via several potential chemical mechanisms. Consequently, their role in photochemical processes remains challenging to assess. This review presents an integrative analysis of the chemistry of halogen radicals and their contribution to aquatic photochemistry in sunlit surface waters and engineered treatment systems. We evaluate existing data on the generation, speciation, and reactivity of halogen radicals, as well as experimental and computational approaches used to obtain this data. By evaluating existing data and identifying major uncertainties, this review provides a basis to assess the impact of halogen radicals on photochemical processes in both saline surface waters and engineered treatment systems.
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Affiliation(s)
- Ke Zhang
- Department of Energy, Environmental & Chemical Engineering , Washington University in St. Louis , Brauer Hall, 1 Brookings Dr. , St Louis , Missouri 63130 , United States
| | - Kimberly M Parker
- Department of Energy, Environmental & Chemical Engineering , Washington University in St. Louis , Brauer Hall, 1 Brookings Dr. , St Louis , Missouri 63130 , United States
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Luo L, Xiao Z, Chen B, Cai F, Fang L, Lin L, Luan T. Natural Porphyrins Accelerating the Phototransformation of Benzo[a]pyrene in Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3634-3641. [PMID: 29465995 DOI: 10.1021/acs.est.7b05854] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Phototransformation is one of the most important transformation pathways of organic contaminants in the water environment. However, how active compounds enable and accelerate the phototransformation of organic pollutants remains to be elucidated. In this study, the phototransformation of benzo[a]pyrene (BaP, the first class "human carcinogens") by various natural porphyrins under solar irradiation was investigated, including chlorophyll a, sodium copper chlorophyllin, hematin, cobalamin, and pheophorbide a. Transformation efficiency of BaP varied considerably with chemical stabilities of the porphyrins. Porphyrins with a lower stability displayed higher BaP transformation efficiencies. BaP transformation had a significant positive correlation with the production of singlet oxygen. Identical phototransformation products of BaP were observed for all investigated porphyrins, and the main products were identified as BaP-quinones, including BaP-1,6-dione, BaP-3,6-dione, and BaP-6,12-dione. The mechanism of natural porphyrins accelerating the BaP phototransformation in water was proposed to proceed via the photocatalytic generation of singlet oxygen resulting in the transformation of BaP to quinones.
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Affiliation(s)
- Lijuan Luo
- State Key Laboratory of Biocontrol, School of Life Sciences , Sun Yat-sen University , Guangzhou 510275 , China
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry , Chinese Academy of Science , Guangzhou 510640 , China
| | - Zhengyu Xiao
- South China Sea Resource Exploitation and Protection Collaborative Innovation Center, School of Marine Sciences , Sun Yat-sen University , Guangzhou 510275 , China
| | - Baowei Chen
- South China Sea Resource Exploitation and Protection Collaborative Innovation Center, School of Marine Sciences , Sun Yat-sen University , Guangzhou 510275 , China
| | - Fengshan Cai
- State Key Laboratory of Biocontrol, School of Life Sciences , Sun Yat-sen University , Guangzhou 510275 , China
| | - Ling Fang
- Instrumental Analysis and Research Center , Sun Yat-sen University , Guangzhou 510275 , China
| | - Li Lin
- State Key Laboratory of Biocontrol, School of Life Sciences , Sun Yat-sen University , Guangzhou 510275 , China
| | - Tiangang Luan
- State Key Laboratory of Biocontrol, School of Life Sciences , Sun Yat-sen University , Guangzhou 510275 , China
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Chen Y, Lu X, Liu L, Wan D, Chen H, Zhou D, Sharma VK. Oxidation of β-blockers by birnessite: Kinetics, mechanism and effect of metal ions. CHEMOSPHERE 2018; 194:588-594. [PMID: 29241133 DOI: 10.1016/j.chemosphere.2017.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/02/2017] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
Manganese dioxides are ubiquitous in natural waters, soils, and sediments and play an important role in oxidative transformation of organic pollutants. This work presents the kinetics of the oxidation of selected β-blockers, betaxolol, metoprolol, and atenolol by birnessite (δ-MnO2) as a function of concentration of the β-blocker, dosage of δ-MnO2, and solution pH. The values of pseudo-first-order rate constants (kobs) of β-blockers decreased in the order betaxolol > atenolol > metoprolol, which was positively correlated with their acid dissociation constants (Ka). Effect of series of metal ions (Fe3+, Cr3+, Al3+, Pb2+, Cu2+, Zn2+, Ni2+, Cd2+, Mg2+, and Ca2+) on the degradation of β-blockers by δ-MnO2 was systematically examined. All of these metal ions inhibited the oxidation reaction under the same constant ionic strength. The inhibition efficiency was positively correlated with the logarithm of stability constant of metal ions in aqueous solution (logKMeOH). By LC-ESI-MS/MS analyses, the oxidation of β-blockers primarily involved hydroxylation and cleavage of the parent molecules to the short branched chain compounds. An electron transfer mechanism for the oxidation of β-blockers by δ-MnO2 was proposed. The oxidation was initiated by the electron transfer from the nonbonding electrons on nitrogen (N-electrons) of β-blockers to δ-MnO2, followed by transformation of radical intermediates. These findings will help to understand the oxidation processes of β-blockers and predict the effect of metal ions on the removal of pollutants by δ-MnO2 in the environment.
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Affiliation(s)
- Yong Chen
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Xiye Lu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lu Liu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Dong Wan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Huabin Chen
- Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan, 430074, China
| | - Danna Zhou
- Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan, 430074, China
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX 77843, USA
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7
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Light-sensitive drugs in topical formulations: stability indicating methods and photostabilization strategies. Future Med Chem 2017; 9:1795-1808. [PMID: 28925725 DOI: 10.4155/fmc-2017-0105] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Photostability tests applied on commercial specialties for topical use have demonstrated a greater vulnerability of several drugs, due to greater exposure to light than other pharmaceutical forms. Photodegradation of a drug can considerably modify its pharmacokinetic behavior by varying the therapeutic index. The evaluation of the degradation profile of a drug, according to the ICH rules, is of primary importance in developing an appropriate topical formulation. Advanced strategies have been proposed to increase the protection from the light of the photolabile drugs. Supramolecular systems have been investigated to improve both pharmacokinetic profile and photostability. In this review, the more recent stability-monitoring methods for the analysis of drugs in topical formulations are collected and the main approaches for the drug photostabilization are discussed.
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8
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Ren D, Huang B, Yang B, Chen F, Pan X, Dionysiou DD. Photobleaching alters the photochemical and biological reactivity of humic acid towards 17α-ethynylestradiol. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 220:1386-1393. [PMID: 27825843 DOI: 10.1016/j.envpol.2016.10.096] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 10/21/2016] [Accepted: 10/31/2016] [Indexed: 06/06/2023]
Abstract
Dissolved humic acid (HA) is ubiquitous in natural waters. Its presence significantly changes the photo-and bio-degradation of some organic pollutants in natural waters. The effects of photobleaching on the composition, photosensitizing property and bioavailability of HA were investigated here along with the subsequent influence on its photochemical and biological reactivity in mediating 17α-ethynylestradiol (EE2) degradation. Photobleaching transformed the refractory HA into some small molecules, including organic acids and aliphatics. Along with composition alteration, the photochemical reactivity of HA towards EE2 was slightly depressed, with 9% of the removal rate inhibited by a 70-h photobleaching. Contrarily, the reactivity of HA in mediating EE2 biodegradation by E. coli was significantly promoted by a short-term photobleaching. Compared to the biodegradation of EE2 in the pristine HA, the 10-h photobleached HA increased the biodegradation removal rate of EE2 by 25%, reaching its peak value of about 60%. However, the EE2 biodegradation was inhibited by further irradiation, and the removal rate of EE2 decreased to that in the pristine HA systems. Because no substrate competition was found between EE2 and formate or glucose, EE2 biodegradation mediated by HA in natural waters may not be affected by coexistent organics. Photodegradation and biodegradation of EE2 mediated by HA thus can be combined together by photobleaching to remove pollutants from natural waters. The results reported here could assist environmental risk assessment with respect to EE2 in natural aquatic systems.
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Affiliation(s)
- Dong Ren
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Bin Huang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Benqin Yang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Fang Chen
- College of Environmental Science and Engineering, China West Normal University, Nanchong 637009, China
| | - Xuejun Pan
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
| | - Dionysios D Dionysiou
- Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA.
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Łukaszewicz P, Maszkowska J, Mulkiewicz E, Kumirska J, Stepnowski P, Caban M. Impact of Veterinary Pharmaceuticals on the Agricultural Environment: A Re-inspection. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2017; 243:89-148. [PMID: 28005213 DOI: 10.1007/398_2016_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The use of veterinary pharmaceuticals (VPs) is a result of growing animal production. Manure, a great crop fertilizer, contains a significant amount of VPs. The investigation of VPs in manure is prevalent, because of the potential risk for environmental organisms, as well as human health. A re-evaluation of the impact of veterinary pharmaceuticals on the agricultural environment is needed, even though several publications appear every year. The aim of this review was to collate the data from fields investigated for the presence of VPs as an inevitable component of manure. Data on VP concentrations in manure, soils, groundwater and plants were collected from the literature. All of this was connected with biotic and abiotic degradation, leaching and plant uptake. The data showed that the sorption of VPs into soil particles is a process which decreases the negative impact of VPs on the microbial community, the pollution of groundwater, and plant uptake. What was evident was that most of the data came from experiments conducted under conditions different from those in the environment, resulting in an overestimation of data (especially in the case of leaching). The general conclusion is that the application of manure on crop fields leads to a negligible risk for plants, bacteria, and finally humans, but in future every group of compounds needs to be investigated separately, because of the high divergence of properties.
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Affiliation(s)
- Paulina Łukaszewicz
- Faculty of Chemistry, Institute for Environmental and Human Health Protection, University of Gdansk, ul. Wita Stwosza 63, Gdańsk, 80-308, Poland
| | - Joanna Maszkowska
- Faculty of Chemistry, Institute for Environmental and Human Health Protection, University of Gdansk, ul. Wita Stwosza 63, Gdańsk, 80-308, Poland
| | - Ewa Mulkiewicz
- Faculty of Chemistry, Institute for Environmental and Human Health Protection, University of Gdansk, ul. Wita Stwosza 63, Gdańsk, 80-308, Poland
| | - Jolanta Kumirska
- Faculty of Chemistry, Institute for Environmental and Human Health Protection, University of Gdansk, ul. Wita Stwosza 63, Gdańsk, 80-308, Poland
| | - Piotr Stepnowski
- Faculty of Chemistry, Institute for Environmental and Human Health Protection, University of Gdansk, ul. Wita Stwosza 63, Gdańsk, 80-308, Poland
| | - Magda Caban
- Faculty of Chemistry, Institute for Environmental and Human Health Protection, University of Gdansk, ul. Wita Stwosza 63, Gdańsk, 80-308, Poland.
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10
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Li Y, Qiao X, Zhou C, Zhang YN, Fu Z, Chen J. Photochemical transformation of sunscreen agent benzophenone-3 and its metabolite in surface freshwater and seawater. CHEMOSPHERE 2016; 153:494-9. [PMID: 27035387 DOI: 10.1016/j.chemosphere.2016.03.080] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/17/2016] [Accepted: 03/17/2016] [Indexed: 05/21/2023]
Abstract
The occurrence of sunscreen agents and their metabolites in surface waters gives rise to public concerns. However, little is known about the environmental fate of these pollutants at present, especially for their metabolites. In this study, we investigated the photochemical of sunscreen agents and their metabolites in natural waters, adopting benzophenone-3 (BP-3) and its human metabolite 4-hydroxybenzophenone (4-OH-BP3) as examples. Results show that only anionic forms of both BP-3 and 4-OH-BP3 can undergo direct photodegradation. The photolytic rates of both compounds in natural waters are faster as compared to those in pure water. Radical scavenging experiments revealed that triplet-excited dissolved organic matter ((3)DOM(∗)) was responsible for the indirect photodegradation of BP-3 and 4-OH-BP3 in seawater, whereas in freshwater, the indirect photodegradation of these two compounds was attributed to (3)DOM(∗) and ·OH. (1)O2 plays a negligible role in their photodegradation because of the weak (1)O2 reactivity. Furthermore, we probed the contribution of ·OH and (3)DOM(∗) to the photodegradation of both compounds in freshwater, and the results revealed that ·OH accounted for 56% and 59% of the observed photodegradation for BP-3 and 4-OH-BP3, respectively, whereas (3)DOM(∗) accounted for 43% and 12% of the observed photodegradation for BP-3 and 4-OH-BP3, respectively. These results are helpful in assessing the ecological risk of BP-3 and its metabolite in the aquatic environment.
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Affiliation(s)
- Yingjie Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Xianliang Qiao
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | - Chengzhi Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Ya-Nan Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhiqiang Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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11
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Chlorophyll catalyse the photo-transformation of carcinogenic benzo[a]pyrene in water. Sci Rep 2015; 5:12776. [PMID: 26239357 PMCID: PMC4523946 DOI: 10.1038/srep12776] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/02/2015] [Indexed: 11/08/2022] Open
Abstract
Algal blooms cause great damage to water quality and aquaculture. However, this study showed that dead algal cells and chlorophyll could accelerate the photo-transformation of benzo[a]pyrene (BaP), a ubiquitous and persistent pollutant with potently mutagenic and carcinogenic toxicities, under visible light irradiation. Chlorophyll was found to be the major active substance in dead algal cells, and generated a high level of singlet oxygen to catalyse the photo-transformation of BaP. According to various BaP metabolites formed, the degradation mechanism was proposed as that chlorophyll in dead algal cells photo-oxidized BaP to quinones via photocatalytic generation of singlet oxygen. The results provided a good insight into the role of chlorophyll in the photo-transformation of organic contaminants and could be a possible remediation strategy of organic pollutants in natural environment.
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12
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de Castro Peixoto AL, Teixeira ACSC. Degradation of amicarbazone herbicide by photochemical processes. J Photochem Photobiol A Chem 2014. [DOI: 10.1016/j.jphotochem.2013.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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