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Deng Q, Tang H, Liu G, Song X, Kang S, Wang H, Ng DHL, Wang G. Photocatalytic degradation of 2,4,4′-trichlorobiphenyl into long-chain alkanes using Ag nanoparticle decorated flower-like ZnO microspheres. NEW J CHEM 2015. [DOI: 10.1039/c5nj00343a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly toxic 2,4,4′-trichlorobiphenyl is completely degraded into long-chain alkanes via the ring-opening reactions and a new photocatalytic degradation pathway.
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Affiliation(s)
- Quan Deng
- Key Laboratory of Materials Physics
- Anhui Key Laboratory of Nanomaterials and Nanostructures
- Institute of Solid State Physics
- Chinese Academy of Sciences
- Hefei 230031
| | - Haibin Tang
- Key Laboratory of Materials Physics
- Anhui Key Laboratory of Nanomaterials and Nanostructures
- Institute of Solid State Physics
- Chinese Academy of Sciences
- Hefei 230031
| | - Gang Liu
- Key Laboratory of Materials Physics
- Anhui Key Laboratory of Nanomaterials and Nanostructures
- Institute of Solid State Physics
- Chinese Academy of Sciences
- Hefei 230031
| | - Xiaoping Song
- Department of Pharmacy
- Anhui Medical College
- Hefei 230601
- P. R. China
| | - Shenhong Kang
- Key Laboratory of Materials Physics
- Anhui Key Laboratory of Nanomaterials and Nanostructures
- Institute of Solid State Physics
- Chinese Academy of Sciences
- Hefei 230031
| | - Huimin Wang
- Key Laboratory of Materials Physics
- Anhui Key Laboratory of Nanomaterials and Nanostructures
- Institute of Solid State Physics
- Chinese Academy of Sciences
- Hefei 230031
| | - Dickon H. L. Ng
- Department of Physics
- The Chinese University of Hong Kong
- Hong Kong
- P. R. China
| | - Guozhong Wang
- Key Laboratory of Materials Physics
- Anhui Key Laboratory of Nanomaterials and Nanostructures
- Institute of Solid State Physics
- Chinese Academy of Sciences
- Hefei 230031
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2
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Wang S, Hao C, Gao Z, Chen J, Qiu J. Theoretical investigation on photodechlorination mechanism of polychlorinated biphenyls. CHEMOSPHERE 2014; 95:200-205. [PMID: 24055025 DOI: 10.1016/j.chemosphere.2013.08.066] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 08/07/2013] [Accepted: 08/16/2013] [Indexed: 06/02/2023]
Abstract
Photodechlorination is a key process affecting the fate and effect of polychlorinated biphenyls (PCBs) in the environment. However, there are still numerous gaps in our knowledge, which become apparent in photodechlorination mechanism of PCBs. We investigated the conformations of 35 PCB congeners in the ground state and the first triplet excited state (T1), and predicted the photodechlorination pathway of the PCBs by calculating bond dissociation energies of the C-Cl bonds and activation energies of the C-Cl bond dissociation in the excited T1 state. Results show that the torsional degree of the two benzene rings of the PCBs depends on the number of ortho chlorines because of steric effect in the ground state. The two benzene rings of the PCBs with low photoreactivity tend to be coplanar and their torsional degree becomes lower in the excited T1 state compared with those in the ground state. The serious deformation and non-coplane of the benzene rings of some PCBs (e.g. PCB138) in the excited T1 state reduces the conjugation between the two benzene rings, implying that these PCBs have high photoreactivity. The dissociation of the C-Cl bond is the rate-determining step in the photodechlorination reactions of PCBs when the hydrogen donor is methanol. The main photodechlorination pathways predicted in this study are in good agreement with previous experimental results. Our results have provided new insights into mechanism of PCBs photodechlorination, which could be useful in the future in utilizing quantum chemistry calculation in investigating the environmental behavior and fate of organic pollutants.
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Affiliation(s)
- Se Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
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3
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Liu P, Xu H, Zhang D, Zhan J. Molecular inclusion of PCB126 by beta-cyclodextrin: a combined molecular dynamics simulation and quantum chemical study. J INCL PHENOM MACRO 2013. [DOI: 10.1007/s10847-012-0199-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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4
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Wei H, Zou Y, Li A, Christensen ER, Rockne KJ. Photolytic debromination pathway of polybrominated diphenyl ethers in hexane by sunlight. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2013; 174:194-200. [PMID: 23274447 DOI: 10.1016/j.envpol.2012.11.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 10/19/2012] [Accepted: 11/29/2012] [Indexed: 06/01/2023]
Abstract
The objective of this work is to identify the photolytic debromination pathways of polybrominated diphenyl ethers (PBDEs). Thirteen PBDEs (BDEs 209, 208, 207, 206, 196, 183, 154, 153, 100, 99, 85, 47 and 28) in hexane were individually exposed to sunlight for up to 64 h. A total of 180 PBDEs were screened and 74 BDE debromination products were detected. The disappearance rate constant increased exponentially with increasing number of bromines. While no evident difference in debromination preference among ortho, meta and para bromines was found for heavier congeners, the vulnerability rank order was meta ≥ ortho > para for the lighter congeners (≤8 Br). The total molar mass of PBDEs continuously decreased during sunlight exposure, indicating PBDEs were transformed to non-PBDE compounds. A stochastic least squares debromination pathway model was developed to simulate the reactions and determine the yields to extend the results beyond the experimental observations.
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Affiliation(s)
- Hua Wei
- School of Public Health, University of Illinois at Chicago, 2121 West Taylor Street, Chicago, IL 60612, USA
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5
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Assessment of silicone as support to investigate the transformation routes of organic chemicals under environmental conditions and UV exposure. Application to selected fungicides. Anal Bioanal Chem 2013; 405:4187-98. [DOI: 10.1007/s00216-013-6821-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/29/2013] [Accepted: 02/04/2013] [Indexed: 10/27/2022]
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6
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Sanchez-Prado L, Kalafata K, Risticevic S, Pawliszyn J, Lores M, Llompart M, Kalogerakis N, Psillakis E. Ice photolysis of 2,2′,4,4′,6-pentabromodiphenyl ether (BDE-100): Laboratory investigations using solid phase microextraction. Anal Chim Acta 2012; 742:90-6. [DOI: 10.1016/j.aca.2012.06.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 10/28/2022]
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7
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Huo LG, Li HD, Zhao CL, Wang WB, Chen ZL, Ding RY, Dong Z, Wang FE, Yang GS, Lu X, Aboul-Enein HY. The Determination of PCBs in Meat and Sea Food by GC-QqQ-MS/MS. FOOD ANAL METHOD 2012. [DOI: 10.1007/s12161-012-9391-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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8
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Liu P, Zhang D, Zhan J. Investigation on the Inclusions of PCB52 with Cyclodextrins by Performing DFT Calculations and Molecular Dynamics Simulations. J Phys Chem A 2010; 114:13122-8. [DOI: 10.1021/jp109306v] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Peng Liu
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People’s Republic of China
| | - Dongju Zhang
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People’s Republic of China
| | - Jinhua Zhan
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People’s Republic of China
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9
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Fernandez-Alvarez M, Llompart M, Garcia-Jares C, Dagnac T, Lores M. Investigation of the photochemical behaviour of pyrethroids lacking the cyclopropane ring by photo-solid-phase microextraction and gas chromatography/mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:3673-3687. [PMID: 19899191 DOI: 10.1002/rcm.4301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The characterization of by-products arising from the UV photodegradation of two insecticide pyrethroids lacking the cyclopropane ring (flucythrinate and fenvalerate) has been investigated by gas chromatography coupled with mass spectrometry (GC/MS). Twenty photoproducts were tentatively identified mainly based on the interpretation of the experimental mass spectra or by using reference mass spectra. Some of these compounds had not previously been detected. Furthermore, the generation of some of the photoproducts might be a matter for concern due to their potential toxicity. The corresponding photodegradation routes, including postulation of the intermediate radicals, have also been proposed. These photodegradation studies were performed by photo-solid-phase microextraction (photo-SPME) in which the SPME fibre was exposed to light after extraction of the target analytes from aqueous solutions. The degradation kinetics of the investigated pyrethroids and the photoformation-photodegradation curves of the photoproducts generated in situ were also monitored through the ion chromatograms obtained for different irradiation times and the corresponding mass spectra.
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Affiliation(s)
- Maria Fernandez-Alvarez
- Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Campus Sur, Universidad de Santiago de Compostela, E-15706 Santiago de Compostela, Spain
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10
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Izadifard M, Achari G, Langford CH. The pathway of dechlorination of PCB congener by a photochemical chain process in 2-propanol: the role of medium and quenching. CHEMOSPHERE 2008; 73:1328-1334. [PMID: 18721997 DOI: 10.1016/j.chemosphere.2008.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 07/01/2008] [Accepted: 07/02/2008] [Indexed: 05/26/2023]
Abstract
As part of a program aimed at developing a field process for cleanup of PCB contaminated soils using photochemistry in basic 2-propanol, additional details of the dechlorination pathway are presented. The mechanism involves a chain reaction with both homolytic photochemical C-Cl bond fission and electron transfer steps producing PCB anion radicals. Kinetics of dechlorination of various congeners show patterns of relative rates associated with the basic 2-propanol medium that are not found in other media because both electron transfer and photochemical homolysis steps determine overall rates of dechlorination and govern the pathways and relative concentrations of intermediates. The electron transfer steps display opposite structure-reactivity correlations to the photo-homolysis, C-Cl bond fission steps. Oxygen quenching is shown to differentially affect both types of steps. In contrast to the suggestion that inter system crossing can be highly efficient with reaction originating from a PCB triplet, oxygen quenching data suggest that a significant minimum of the quantum yield is non-quenchable, presumably because of a reaction path from the PCB singlet. This may help to explain why exclusion of air is not entirely necessary in practice.
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Affiliation(s)
- Maryam Izadifard
- Department of Chemistry, University of Calgary, 2500 University Dr. NW Calgary, AB, Canada T2N 1N4
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11
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Sanchez-Prado L, Llompart M, Lores M, García-Jares C, Bayona JM, Cela R. Monitoring the photochemical degradation of triclosan in wastewater by UV light and sunlight using solid-phase microextraction. CHEMOSPHERE 2006; 65:1338-47. [PMID: 16735047 DOI: 10.1016/j.chemosphere.2006.04.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 04/05/2006] [Accepted: 04/06/2006] [Indexed: 05/09/2023]
Abstract
Photo solid-phase microextraction (photo-SPME) is applied for the first time to study the photochemical behavior of an emerging pollutant, triclosan, in real contaminated wastewater samples using a solar simulator. In this study, water samples are extracted by SPME and then, the fiber coating is irradiated for a selected time. This on-fiber procedure, so-called photo-SPME, followed by gas chromatography-mass spectrometry makes it possible to study photodegradation kinetics and the generation of byproducts. Several photoproducts were identified in the real samples including the 2,8-dichlorodibenzo-p-dioxin, dichlorophenols and a compound tentatively identified as other DCDD congener or a dichlorohydroxydibenzofuran. Accordingly, it was possible to postulate main photodegradation mechanisms. Photo-SPME demonstrated slower kinetics in wastewater than in spiked ultrapure water probably due to the presence of dissolved organic matter. This technique was extensively compared with conventional aqueous photodegradation showing high similarity. The influence of pH on the triclosan photolysis and on the triclosan-dioxin conversion was also investigated in wastewater. Photodegradation of triclosan and formation of 2,8-DCDD occurred independently of sample pH. This study represents an advance in the use of photo-SPME to understand the photochemical fate of environmental organic pollutants and demonstrates its clear advantages with real samples.
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Affiliation(s)
- Lucia Sanchez-Prado
- Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
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12
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Sánchez-Prado L, Lores M, Llompart M, García-Jares C, Bayona JM, Cela R. Natural sunlight and sun simulator photolysis studies of tetra- to hexa-brominated diphenyl ethers in water using solid-phase microextraction. J Chromatogr A 2006; 1124:157-66. [PMID: 16824536 DOI: 10.1016/j.chroma.2006.06.037] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 06/09/2006] [Accepted: 06/12/2006] [Indexed: 11/25/2022]
Abstract
Photo-solid-phase microextraction (photo-SPME) is combined for the first time with natural and simulated sunlight to study the photochemical behaviour of environmental concerning tetra- to hexa-brominated diphenyl ethers. The sunlight photodegradation kinetics of five brominated diphenyl ethers (BDE 47, BDE 100, BDE 99, BDE 154 and BDE 153) has been studied. These BDEs are the most abundant congeners in penta-BDE commercial formulations used as flame-retardants and are considered among the most toxic ones. The five studied BDEs were photolytically labile. The detected photodegradation products include more stable lower brominated diphenyl ethers and polybrominated dibenzofurans (PBDFs). The photoformation and decay kinetics of these photoproducts were also monitorized by photo-SPME. Aqueous photodegradation studies have also been carried out. In this case, SPME is only used as the extraction technique. Obtained results in the aqueous photodegradation experiments were compared with those obtained in photo-SPME experiments.
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Affiliation(s)
- Lucía Sánchez-Prado
- Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, Avda. das Ciencias s/n, 15782 Santiago de Compostela, Spain
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13
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Sánchez-Prado L, González-Barreiro C, Lores M, Llompart M, García-Jares C, Cela R. Photochemical studies of a polybrominated diphenyl ethers (PBDES) technical mixture by solid phase microextraction (SPME). CHEMOSPHERE 2005; 60:922-8. [PMID: 15992599 DOI: 10.1016/j.chemosphere.2005.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 12/22/2004] [Accepted: 01/13/2005] [Indexed: 05/03/2023]
Abstract
In this work the photochemical behaviour of a technical mixture of polybrominated diphenyl ethers (PBDEs) (BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154) has been studied. The mixture of BDEs was extracted from aqueous solutions using SPME fibers that were subsequently exposed to different UV irradiation times, procedure so-called Photo-SPME. PBDEs photochemical studies in such medium have been accomplished for the first time. Twenty one different photoproducts, all of them generated by successive bromine atoms losses, have been identified, being their photoformation-photodegradation curves easily determined by the Photo-SPME technique.
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Affiliation(s)
- L Sánchez-Prado
- Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Instituto de Investigación y Análisis Alimentario (IIAA), Universidad de Santiago de Compostela, Avda. das Ciencias S/N, Campus Sur. E-15782, Santiago de Compostela, Spain
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14
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Dabrowska D, Kot-Wasik A, Namieśnik J. Pathways and Analytical Tools in Degradation Studies of Organic Pollutants. Crit Rev Anal Chem 2005. [DOI: 10.1080/10408340500207565] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Sanchez-Prado L, Llompart M, Lores M, Garcia-Jares C, Cela R. Investigation of photodegradation products generated after UV-irradiation of five polybrominated diphenyl ethers using photo solid-phase microextraction. J Chromatogr A 2005; 1071:85-92. [PMID: 15865178 DOI: 10.1016/j.chroma.2004.10.065] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In this study, the photoinduced degradation of five polybrominated diphenyl ethers (PBDEs), BDE-47, BDE-100, BDE-99, BDE-154 and BDE-153, is studied using solid-phase microextraction polydimethylsiloxane fibers as photolytic support. PBDEs are extracted from aqueous solutions using SPME fibers that are subsequently exposed to UV irradiation for different times (from 2 to 60 min). Photodegradation kinetics of the five PBDEs, tentative identification and photochemical behavior of the generated photoproducts, as well as photodegradation pathways, have been studied employing this on-fiber approach technique (photo-SPME) followed by gas chromatography-mass spectrometry analysis. Aqueous photodegradation studies have also been performed and compared with photo-SPME. All the photoproducts detected in the aqueous experiments were previously found in the photo-SPME experiments. In this study, reductive debromination by successive losses of bromine atoms is confirmed as the main photodegradation pathway of PBDEs. A large number of PBDEs were obtained as photoproducts of the five target analytes. Other mechanism of photodegradation observed was intramolecular cyclization from the homolytic dissociation of the C-Br bond; thus, polybromo-dibenzofurans were generated. This work contributes to the study of the photodegradation of PBDEs and shows the potential of photo-SPME to evaluate the photo-transformation of organic pollutants.
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Affiliation(s)
- Lucia Sanchez-Prado
- Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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16
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Lores M, Llompart M, Sanchez-Prado L, Garcia-Jares C, Cela R. Confirmation of the formation of dichlorodibenzo-p-dioxin in the photodegradation of triclosan by photo-SPME. Anal Bioanal Chem 2005; 381:1294-8. [PMID: 15702305 DOI: 10.1007/s00216-004-3047-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Revised: 12/02/2004] [Accepted: 12/11/2004] [Indexed: 11/28/2022]
Abstract
Photodegradation is a possible way to eliminate organic pollutants from the environment but, at the same time, can be a source of toxic byproducts. The photochemical conversion of triclosan, a common pollutant in continental waters, into dichlorodibenzo-p-dioxin (DCDD) has been confirmed in our preliminary experiments employing photo-SPME (photo-solid-phase microextraction) using 18-W UV irradiation at 254-nm wavelength. Under these conditions, triclosan is rapidly photodegraded (70% of triclosan was degraded in 2 min); the most important novel aspect of this work is the conversion of triclosan to DCDD directly on the polydimethylsiloxane coating of the SPME fiber. Moreover, this conversion is also confirmed in non-buffered aqueous photodegradation experiments using SPME as the extraction technique. In all the experiments of this study, analysis was carried out by gas chromatography-electronic impact mass spectrometry (GC-EI/MS).
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Affiliation(s)
- Marta Lores
- Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Quimica' Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Avda. das Ciencias s/n, 15782, Santiago de Compostela, Spain.
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17
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Sanchez-Prado L, Lores M, Llompart M, Garcia-Jares C, Lourido M, Cela R. Further solid-phase microextraction–gas chromatography–mass spectrometry applications: “on-fibre” and aqueous photodegradation of nitro musks. J Chromatogr A 2004. [DOI: 10.1016/j.chroma.2004.07.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Sanchez-Prado L, Llompart M, Lores M, Garcia-Jares C, Cela R. Application of solid-phase microextraction to the study of the photochemical behaviour of five priority pesticides: “on-fiber” and aqueous photodegradation. J Chromatogr A 2004; 1047:271-9. [PMID: 15460259 DOI: 10.1016/j.chroma.2004.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Solid-phase microextraction (SPME) is applied to study the photochemical degradation of five priority pesticides: atrazine, alachlor, aldrin, dieldrin, endrin. Analyses were carried out by gas chromatography-mass spectrometry. The possibility of studying the photochemical degradation of the target compounds in solid-phase microextraction fibers, "photo-SPME", is evaluated employing different SPME coatings. The target analytes were extracted from aqueous solutions using different commercial coatings and then, the fibers were exposed to UV light. Results indicated that on-fiber photodegradation takes place in a considerably major extent using PDMS coating for an irradiation time of 30min. On-fiber photodegradation kinetics of each analyte were determined by UV irradiation of the PDMS for different times. A large number of photoproducts were generated and they were tentatively identified by means of their mass spectra and with the aid of literature. In this way, main photodegradation mechanisms could be postulated. Aqueous photodegradation studies followed by SPME were performed and compared with photo-SPME. All the photoproducts detected in the aqueous experiments were previously found in the photo-SPME experiments. This study shows the potential of photo-SPME to evaluate the photo-transformation of organic pollutants.
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Affiliation(s)
- Lucia Sanchez-Prado
- Departamento de Química Analitica, Nutricion y Bromatología, Facultad de Química, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Avda das Ciencias s/n, 15706 Santiago de Compostela, Spain
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Sosa Ferrera Z, Padrón Sanz C, Mahugo Santana C, Santana Rodrı́guez JJ. The use of micellar systems in the extraction and pre-concentration of organic pollutants in environmental samples. Trends Analyt Chem 2004. [DOI: 10.1016/s0165-9936(04)00732-0] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Arrebola FJ, Cortes Aguado S, Sánchez‐Morito N, Garrido Frenich A, Martínez Vidal JL. Pesticide Residue Analysis in Waters by Solid‐Phase Microextraction Coupled to Gas Chromatography‐Tandem Mass Spectrometry. ANAL LETT 2004. [DOI: 10.1081/al-120027776] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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21
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Shu YY, Wang SS, Tardif M, Huang Y. Analysis of polychlorinated biphenyls in aqueous samples by microwave-assisted headspace solid-phase microextraction. J Chromatogr A 2003; 1008:1-12. [PMID: 12943246 DOI: 10.1016/s0021-9673(03)00967-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The hyphenated technique namely microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) was developed and studied for the simultaneous extraction/enrichment of polychlorinated biphenyls (PCBs) in aqueous samples prior to the quantification by gas chromatography (GC). The PCBs in aqueous media are extracted onto a solid-phase micro fibre via the headspace with the aid of microwave irradiation. The optimum conditions for obtaining extraction efficiency, such as the extraction time, addition of salts, addition of methanol, ratio of sample to headspace volume, and the desorption parameters were investigated. Experimental results indicated that the proposed MA-HS-SPME method attained the best extraction efficiency under the optimized conditions, i.e., irradiation of extraction solution (20 ml aqueous sample in 40 ml headspace vial with no additions of salt and methanol) under 30 W microwave power for 15 cycles (1 min power on and 3 min power off of each cycle). Desorption at 270 degrees C for 3 min provided the best detection results. The detection limit obtained were between 0.27 and 1.34 ng/l. The correlation coefficient for the linear dynamic range from 1 to 80 ng/l exceeded 0.99 for 18 PCBs.
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Affiliation(s)
- Youn Yuen Shu
- Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan.
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23
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Llompart M, Lores M, Lourido M, Sánchez-Prado L, Cela R. On-fiber photodegradation after solid-phase microextraction of p,p'-DDT and two of its major photoproducts, p,p'-DDE and p,p'-DDD. J Chromatogr A 2003; 985:175-83. [PMID: 12580484 DOI: 10.1016/s0021-9673(02)01394-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The potential of performing photochemical studies in solid phase microextraction (SPME) fibers, "photo-SPME", to study the photodegradation of p,p'-DDT and two of its major degradation products, p,p'-DDE and p,p'-DDD, is shown. Analyses were carried out by gas chromatography mass spectroscopy detection. DDT was extracted from aqueous solutions using five different commercial coatings. The fibers were then exposed to UV light emitted by a low-pressure mercury lamp. After 30 min of irradiation, the degradation of DDT only occurred in polydimethylsiloxane fibers. The on-fiber degradation kinetics of p,p'-DDT was studied from 2 to 60 min. A large number of photoproducts were generated and their kinetic behavior was studied. In order to clarify the possible photoreaction pathways for DDT, individual water solutions containing p,p'-DDD or p.p'-DDE were prepared and photo-SPME was performed for each compound at different irradiation times. On the basis of the photoproducts identified, some photodegradation pathways are proposed. Finally, aqueous photodegradation studies followed by SPME were performed and compared to the photo-SPME. This work will show the enormous potential of photo-SPME to perform photodegradation studies.
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Affiliation(s)
- María Llompart
- Departamento de Química Analítica, Nutrición Bromatologia, Facultad de Química, Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, E-15706 Santiago de Compostela, Spain.
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Lores M, Llompart M, González-García R, González-Barreiro C, Cela R. Photolysis of polychlorinated biphenyls by solid-phase microextraction. "On-fibre" versus aqueous photodegradation. J Chromatogr A 2002; 963:37-47. [PMID: 12187992 DOI: 10.1016/s0021-9673(02)00555-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The photodegradation kinetics of polychlorinated biphenyls "on-fibre" is described. The utilisation of solid-phase microextraction (SPME) fibres to monitor photolysis pathways and determine photoproducts constitutes a new approach that exploits the solvent-free aspect and concentration possibilities of this technique. Direct photolysis of aqueous solutions containing polychlorinated biphenyls (PCBs) was also undertaken and SPME was used in this case for photoproduct extraction purposes. Reductive dechlorination was the main decomposition mechanism in both procedures. Less-chlorinated biphenyls are the principal photoproducts and, among these, some toxic coplanar species have been detected. The influence of irradiation time was evaluated for both treatments. SPME was found to be a good choice for the extraction of photoproducts in experiments conducted in the classical way (extraction after photolysis). Moreover, it is demonstrated that photolysis of PCBs "on fibre" is realistic and provides the possibility of evaluating the phototransformation of these pollutants at environmental levels.
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Affiliation(s)
- M Lores
- Departamento de Química Analítica, Nutrición y Bromatologia, Facultad de Química, Universidad de Santiago de Compostela, Spain.
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