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Chen X, Wang J, Wu H, Zhu Z, Zhou J, Guo H. Trade-off effect of dissolved organic matter on degradation and transformation of micropollutants: A review in water decontamination. JOURNAL OF HAZARDOUS MATERIALS 2023; 450:130996. [PMID: 36867904 DOI: 10.1016/j.jhazmat.2023.130996] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/24/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
The degradation of micropollutants by various treatments is commonly affected by the ubiquitous dissolved organic matter (DOM) in the water environment. To optimize the operating conditions and decomposition efficiency, it is necessary to consider the impacts of DOM. DOM exhibits varied behaviors in diverse treatments, including permanganate oxidation, solar/ultraviolet photolysis, advanced oxidation processes, advanced reduction process, and enzyme biological treatments. Besides, the different sources (i.e., terrestrial and aquatic, etc) of DOM, and operational circumstances (i.e., concentration and pH) fluctuate different transformation efficiency of micropollutants in water. However, so far, systematic explanations and summaries of relevant research and mechanism are rare. This paper reviewed the "trade-off" performances and the corresponding mechanisms of DOM in the elimination of micropollutants, and summarized the similarities and differences for the dual roles of DOM in each of the aforementioned treatments. Inhibition mechanisms typically include radical scavenging, UV attenuation, competition effect, enzyme inactivation, reaction between DOM and micropollutants, and intermediates reduction. Facilitation mechanisms include the generation of reactive species, complexation/stabilization, cross-coupling with pollutants, and electron shuttle. Moreover, electron-drawing groups (i.e., quinones, ketones functional groups) and electron-supplying groups (i.e., phenols) in the DOM are the main contributors to its trade-off effect.
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Affiliation(s)
- Xingyu Chen
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Jingquan Wang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Han Wu
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Zhuoyu Zhu
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Jianfei Zhou
- National Engineering Research Center of Clean Technology in Leather Industry, Sichuan University, Chengdu 610065, China.
| | - Hongguang Guo
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Yibin Industrial Technology Research Institute of Sichuan University, Yibin 644000, China.
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2
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Arachchi S, Palma SP, Sanders CI, Xu H, Ghosh Biswas R, Soong R, Simpson AJ, Casabianca LB. Binding Between Antibiotics and Polystyrene Nanoparticles Examined by NMR. ACS ENVIRONMENTAL AU 2022; 3:47-55. [PMID: 36691656 PMCID: PMC9856636 DOI: 10.1021/acsenvironau.2c00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 01/19/2023]
Abstract
Elucidating the interactions between plastic nanoparticles and small molecules is important to understanding these interactions as they occur in polluted waterways. For example, plastic that breaks down into micro- and nanoscale particles will interact with small molecule pollutants that are also present in contaminated waters. Other components of natural water, such as dissolved organic matter, will also influence these interactions. Here we use a collection of complementary NMR techniques to examine the binding between polystyrene nanoparticles and three common antibiotics, belonging to a class of molecules that are expected to be common in polluted water. Through examination of proton NMR signal intensity, relaxation times, saturation-transfer difference (STD) NMR, and competition STD-NMR, we find that the antibiotics have binding strengths in the order amoxicillin < metronidazole ≪ levofloxacin. Levofloxacin is able to compete for binding sites, preventing the other two antibiotics from binding. The presence of tannic acid disrupts the binding between levofloxacin and the polystyrene nanoparticles, but does not influence the binding between metronidazole and these nanoparticles.
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Affiliation(s)
- Saduni
S. Arachchi
- Department
of Chemistry, Clemson University, Clemson, South Carolina29634, United States
| | - Stephanie P. Palma
- Department
of Chemistry, Clemson University, Clemson, South Carolina29634, United States
| | - Charlotte I. Sanders
- Department
of Chemistry, Clemson University, Clemson, South Carolina29634, United States
| | - Hui Xu
- Department
of Chemistry, Clemson University, Clemson, South Carolina29634, United States
| | - Rajshree Ghosh Biswas
- Department
of Chemistry, University of Toronto Scarborough, Toronto, OntarioM1C 1A4, Canada
| | - Ronald Soong
- Department
of Chemistry, University of Toronto Scarborough, Toronto, OntarioM1C 1A4, Canada
| | - André J. Simpson
- Department
of Chemistry, University of Toronto Scarborough, Toronto, OntarioM1C 1A4, Canada
| | - Leah B. Casabianca
- Department
of Chemistry, Clemson University, Clemson, South Carolina29634, United States,
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3
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Cai X, Qi K, Zhang X, Xie X, Wang Z. The binding characteristics of sediment-derived dissolved organic matter with ceftazidime: a microstructural and spectroscopic correlation study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:30712-30723. [PMID: 34994932 DOI: 10.1007/s11356-021-18431-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
This research focused on the characterization of sediment-derived dissolved organic matter (SDOM) extracted from sediment of Yellow River and the binding behaviors of ceftazidime (CAZ) with the presence of SDOM. The morphology, surface composition and structure of SDOM and the complexation between SDOM and CAZ in terms of component features, binding capacity and sequence were studied by multiple approaches. Results showed that SDOM was in situ autochthonous-dominated with a low weight-average molecular weight and aromaticity (the value of SR was 2.523). The multiple morphological characteristics, high surface oxygen contents (53.49%) and more aliphatic (H/C = 1.91) of SDOM were further confirmed. Studies on SDOM-CAZ interaction suggested that the functional groups and chemical compositions of SDOM were susceptible to CAZ. In more detail, the aromatic protons and aliphatic protons of CAZ impacted significantly, and the binding between CAZ and SDOM might relate to noncovalent. The protein-like fractions were considered to be the primary participant with 49% fractions lost and the aromatics and amides as mainly active site interaction with CAZ. These findings have significant implications on the environmental fate of cephalosporin antibiotics and that of sediment-derived DOM.
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Affiliation(s)
- Xuewei Cai
- College of Earth and Environmental Sciences, Key Laboratory for Environmental Pollution Prediction and Control, Lanzhou University, Gansu Province, Lanzhou, 730000, People's Republic of China
| | - Kemin Qi
- College of Earth and Environmental Sciences, Key Laboratory for Environmental Pollution Prediction and Control, Lanzhou University, Gansu Province, Lanzhou, 730000, People's Republic of China
| | - Xiaoli Zhang
- College of Earth and Environmental Sciences, Key Laboratory for Environmental Pollution Prediction and Control, Lanzhou University, Gansu Province, Lanzhou, 730000, People's Republic of China
| | - Xiaoyun Xie
- College of Earth and Environmental Sciences, Key Laboratory for Environmental Pollution Prediction and Control, Lanzhou University, Gansu Province, Lanzhou, 730000, People's Republic of China.
| | - Zhaowei Wang
- College of Earth and Environmental Sciences, Key Laboratory for Environmental Pollution Prediction and Control, Lanzhou University, Gansu Province, Lanzhou, 730000, People's Republic of China
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4
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Yang B, Cheng X, Zhang Y, Li W, Wang J, Guo H. Probing the roles of pH and ionic strength on electrostatic binding of tetracycline by dissolved organic matters: Reevaluation of modified fitting model. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2021; 8:100133. [PMID: 36156988 PMCID: PMC9488040 DOI: 10.1016/j.ese.2021.100133] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/15/2021] [Accepted: 11/15/2021] [Indexed: 05/06/2023]
Abstract
The binding performance of dissolved organic matters (DOM) plays a critical role in the migration, diffusion and removal of various residual pollutants in the natural water environment. In the current study, four typical DOMs (including bovine serum proteins BSA (proteins), sodium alginate SAA (polysaccharides), humic acid HA and fulvic acid FA (humus)) are selected to investigate the binding roles in zwitterionic tetracycline (TET) antibiotic under various ionic strength (IS = 0.001-0.1 M) and pH (5.0-9.0). The dialysis equilibration technique was employed to determine the binding concentrations of TET, and the influence of IS and pH on binding performance was evaluated via UV-vis spectroscopy, total organic carbon (TOC), and Excitation-Emission-Matrix spectra (EEM), zeta potentials and molecule size distribution analysis. Our results suggested that carboxyl and phenolic hydroxyl were identified as the main contributors to TET binding based on the fourier transform infrared spectroscopy (FTIR) analysis, and the binding capability of four DOMs followed as HA > FA » BSA > SAA. The biggest binding concentrations of TET by 10 mg C/L HA, FA, BSA and SAA were 0.863 μM, 0.487 μM, 0.084 μM and 0.086 μM, respectively. The higher binding capability of HA and FA is mainly attributed to their richer functional groups, lower zeta potential (HA/FA = -15.92/-13.54 mV) and the bigger molecular size (HA/FA = 24668/27750 nm). IS significantly inhibits the binding interaction by compressing the molecular structure and the surface electric double layer, while pH had a weak effect. By combining the Donnan model and the multiple linear regression analysis, a modified Karickhoff model was established to effectively predict the binding performance of DOM under different IS (0.001-0.1 M) and pH (5.0-9.0) conditions, and the R2 of linear fitting between experiment-measured logKDOC and model-calculated logKOC were 0.94 for HA and 0.91 for FA. This finding provides a theoretical basis for characterizing and predicting the binding performance of various DOMs to residual micropollutants in the natural water environment.
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Affiliation(s)
- Bo Yang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Xin Cheng
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Yongli Zhang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Wei Li
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Jingquan Wang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Hongguang Guo
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
- Corresponding author.
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Anaraki MT, Lysak DH, Downey K, Kock FVC, You X, Majumdar RD, Barison A, Lião LM, Ferreira AG, Decker V, Goerling B, Spraul M, Godejohann M, Helm PA, Kleywegt S, Jobst K, Soong R, Simpson MJ, Simpson AJ. NMR spectroscopy of wastewater: A review, case study, and future potential. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 126-127:121-180. [PMID: 34852923 DOI: 10.1016/j.pnmrs.2021.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
NMR spectroscopy is arguably the most powerful tool for the study of molecular structures and interactions, and is increasingly being applied to environmental research, such as the study of wastewater. With over 97% of the planet's water being saltwater, and two thirds of freshwater being frozen in the ice caps and glaciers, there is a significant need to maintain and reuse the remaining 1%, which is a precious resource, critical to the sustainability of most life on Earth. Sanitation and reutilization of wastewater is an important method of water conservation, especially in arid regions, making the understanding of wastewater itself, and of its treatment processes, a highly relevant area of environmental research. Here, the benefits, challenges and subtleties of using NMR spectroscopy for the analysis of wastewater are considered. First, the techniques available to overcome the specific challenges arising from the nature of wastewater (which is a complex and dilute matrix), including an examination of sample preparation and NMR techniques (such as solvent suppression), in both the solid and solution states, are discussed. Then, the arsenal of available NMR techniques for both structure elucidation (e.g., heteronuclear, multidimensional NMR, homonuclear scalar coupling-based experiments) and the study of intermolecular interactions (e.g., diffusion, nuclear Overhauser and saturation transfer-based techniques) in wastewater are examined. Examples of wastewater NMR studies from the literature are reviewed and potential areas for future research are identified. Organized by nucleus, this review includes the common heteronuclei (13C, 15N, 19F, 31P, 29Si) as well as other environmentally relevant nuclei and metals such as 27Al, 51V, 207Pb and 113Cd, among others. Further, the potential of additional NMR methods such as comprehensive multiphase NMR, NMR microscopy and hyphenated techniques (for example, LC-SPE-NMR-MS) for advancing the current understanding of wastewater are discussed. In addition, a case study that combines natural abundance (i.e. non-concentrated), targeted and non-targeted NMR to characterize wastewater, along with in vivo based NMR to understand its toxicity, is included. The study demonstrates that, when applied comprehensively, NMR can provide unique insights into not just the structure, but also potential impacts, of wastewater and wastewater treatment processes. Finally, low-field NMR, which holds considerable future potential for on-site wastewater monitoring, is briefly discussed. In summary, NMR spectroscopy is one of the most versatile tools in modern science, with abilities to study all phases (gases, liquids, gels and solids), chemical structures, interactions, interfaces, toxicity and much more. The authors hope this review will inspire more scientists to embrace NMR, given its huge potential for both wastewater analysis in particular and environmental research in general.
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Affiliation(s)
- Maryam Tabatabaei Anaraki
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada
| | - Daniel H Lysak
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada
| | - Katelyn Downey
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada
| | - Flávio Vinicius Crizóstomo Kock
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada; Department of Chemistry, Federal University of São Carlos-SP (UFSCar), São Carlos, SP, Brazil
| | - Xiang You
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada
| | - Rudraksha D Majumdar
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada; Synex Medical, 2 Bloor Street E, Suite 310, Toronto, ON M4W 1A8, Canada
| | - Andersson Barison
- NMR Center, Federal University of Paraná, CP 19081, 81530-900 Curitiba, PR, Brazil
| | - Luciano Morais Lião
- NMR Center, Institute of Chemistry, Universidade Federal de Goiás, Goiânia 74690-900, Brazil
| | | | - Venita Decker
- Bruker Biospin GmbH, Silberstreifen 4, 76287 Rheinstetten, Germany
| | | | - Manfred Spraul
- Bruker Biospin GmbH, Silberstreifen 4, 76287 Rheinstetten, Germany
| | | | - Paul A Helm
- Environmental Monitoring & Reporting Branch, Ontario Ministry of the Environment, Toronto M9P 3V6, Canada
| | - Sonya Kleywegt
- Technical Assessment and Standards Development Branch, Ontario Ministry of the Environment, Conservation and Parks, Toronto, ON M4V 1M2, Canada
| | - Karl Jobst
- Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Ronald Soong
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada
| | - Myrna J Simpson
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada
| | - Andre J Simpson
- Environmental NMR Center, University of Toronto Scarborough, 1265 Military Trail, Toronto M1C1A4, Canada.
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6
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Chaubey B, Singh P, Pal S. Solution-state NMR evaluation of molecular interaction between monoaromatic carboxylic acids and dissolved humic acid. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:17775-17788. [PMID: 33400107 DOI: 10.1007/s11356-020-12092-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Understanding the nature of interactions between the aromatic organic pollutants with dissolved humic acid (HA) is fundamental for the prediction of their environmental fate and subsequent development of efficient remediation methods. The present study employs solution-state 1H/19F NMR methods to investigate the non-covalent interaction between aqueous peat humic acid (Aldrich HA) and monoaromatic carboxylic acids (CA), viz., 2, 6 diflourobenzoic acid (DFBA) and its non-fluorinated analog, benzoic acid (BA). NMR self-diffusion measurement of HA protons confirmed micellar nature indicating possibility of encapsulation of small molecules through host-guest interaction. 19F-1H and 1H-1H saturation transfer difference (STD) experiments reveal the mode of insertion of CA into HA superstructure. The strength of interaction has been evaluated by analyzing T1/T2 relaxation times and self-diffusion coefficients of CA as a function of HA concentration. Association constants extracted for CA-HA complexes from NMR diffusion experiments reflected that the association between DFBA-HA (2.34 mM-1) is significantly higher than that of BA-HA (0.97 mM-1). The experimental outcome reiterated that substitution of -H with halogen atoms (-F in specific) to aromatic ring plays a dominant role in modulating the strength of association and mode of insertion of organic pollutants into HA superstructure. The present study emphasizes that AHA can be a potential remediating agent for organic contaminants due to its superior binding affinity compared to less humified extracted HA (EHA) from Karwar, Rajasthan, India.
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Affiliation(s)
- Bhawna Chaubey
- Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342037, India
| | - Pooja Singh
- Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342037, India
| | - Samanwita Pal
- Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342037, India.
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Zhu X, Song X, Schwarzbauer J. First insights into the formation and long-term dynamic behaviors of nonextractable perfluorooctanesulfonate and its alternative 6:2 chlorinated polyfluorinated ether sulfonate residues in a silty clay soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143230. [PMID: 33158517 DOI: 10.1016/j.scitotenv.2020.143230] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/15/2020] [Accepted: 10/17/2020] [Indexed: 06/11/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent and toxic contaminants that are ubiquitous in the environment. They can incorporate into soil as nonextractable residues (NER) which are not detectable with conventional analytical protocols but are still possible to remobilize with changes of surrounding conditions, and thus will be bioavailable again. Therefore, there is a need to investigate thoroughly the long-term fate of NER-PFAS. In this study, a 240-day incubation of perfluorooctanesulfonate (PFOS) and its alternative 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) in a silty clay topsoil was carried out. Solvent extraction, alkaline hydrolysis and sequential chemical degradation were applied on periodically sampled soil to obtain extractable, moderately bound and deeply bound PFAS, respectively. The results confirmed the formation of NER of both compounds but with different preferences of incorporating mechanisms. NER-PFOS was formed predominantly by covalent binding (via head group) and strong adsorption (via tail group). The formation of NER-F-53B was mainly driven by physical entrapment. Both bound compounds within the incubation period showed three-stage behaviors including an initial period with slight release followed by a (re) incorporating stage and a subsequent remobilizing stage. This work provides some first insights on the long-term dynamic behaviors of nonextractable PFAS and will be conducive to their risk assessment and remediation (e.g. estimating potential NER-PFAS level based on their free extractable level, and selecting remediation methods according to their prevailing binding mechanisms).
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Affiliation(s)
- Xiaojing Zhu
- Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr, 4-20, 52064 Aachen, Germany.
| | - Xin Song
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China.
| | - Jan Schwarzbauer
- Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr, 4-20, 52064 Aachen, Germany.
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Chaubey B, Narwal P, Khandelwal A, Pal S. Aqueous photo-degradation of Flupyradifurone (FPD) in presence of a natural Humic Acid (HA): A quantitative solution state NMR analysis. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.112986] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Zhao X, Hu Z, Yang X, Cai X, Wang Z, Xie X. Noncovalent interactions between fluoroquinolone antibiotics with dissolved organic matter: A 1H NMR binding site study and multi-spectroscopic methods. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:815-822. [PMID: 30852295 DOI: 10.1016/j.envpol.2019.02.077] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 02/18/2019] [Accepted: 02/21/2019] [Indexed: 06/09/2023]
Abstract
Fluoroquinolone antibiotics (FQs) are considered to be emerging environmental contaminants that have been detected extensively in aquatic environment. It is of quite importance to explore FQs interacting with dissolved organic matter (DOM). The interactions of FQs with DOM were examined by nuclear magnetic resonance (NMR) spectroscopy, fluorescence quenching, UV-vis, Fourier transform infrared (FT-IR) spectroscopic techniques. The bindings of FQs to DOM had one single binding site and their quenching mechanisms were static, which were evaluated by the Stern-Volmer and Site-binding equations. Addition of DOM could result in micro-environmental changes of fluorophores groups in FQs. The location adjacent oxygen right of Ofloxacin (OFL) and the aromatic ring (the adjacency replaced by two nitrogen-containing groups) of Ciprofloxacin (CIP), Enrofloxacin (ENR), Norfloxacin (NOR) might be highly affected by DOM molecule. The negative enthalpy change (ΔH0), negative entropy change (ΔS0) and the positive Gibbs' energy change (ΔG0) figured out that the binding processes were exothermic but not thermodynamic favorable, the formation of HA-FQs complexes would be powered chiefly by the ΔS0. H-bonding, electrostatic effect, van der Waals force were the acting force in the binding reactions and the π-π stacking effect was the major binding force under alkaline conditions. Moreover, the protonated, deprotonated, or partially protonated state of FQs were found to have different binding capacity to DOM, and the binding reactions for FQs-HA system were suppressed as the ionic strength increased. Meanwhile, alterations of FQs conformation in the presence of DOM were evaluated by FT-IR and UV-vis spectra.
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Affiliation(s)
- Xiating Zhao
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Zhongzheng Hu
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xing Yang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xuewei Cai
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Zhaowei Wang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xiaoyun Xie
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
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10
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Bastawrous M, Jenne A, Tabatabaei Anaraki M, Simpson AJ. In-Vivo NMR Spectroscopy: A Powerful and Complimentary Tool for Understanding Environmental Toxicity. Metabolites 2018; 8:E35. [PMID: 29795000 PMCID: PMC6027203 DOI: 10.3390/metabo8020035] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/19/2018] [Accepted: 05/21/2018] [Indexed: 12/17/2022] Open
Abstract
Part review, part perspective, this article examines the applications and potential of in-vivo Nuclear Magnetic Resonance (NMR) for understanding environmental toxicity. In-vivo NMR can be applied in high field NMR spectrometers using either magic angle spinning based approaches, or flow systems. Solution-state NMR in combination with a flow system provides a low stress approach to monitor dissolved metabolites, while magic angle spinning NMR allows the detection of all components (solutions, gels and solids), albeit with additional stress caused by the rapid sample spinning. With in-vivo NMR it is possible to use the same organisms for control and exposure studies (controls are the same organisms prior to exposure inside the NMR). As such individual variability can be reduced while continual data collection over time provides the temporal resolution required to discern complex interconnected response pathways. When multidimensional NMR is combined with isotopic labelling, a wide range of metabolites can be identified in-vivo providing a unique window into the living metabolome that is highly complementary to more traditional metabolomics studies employing extracts, tissues, or biofluids.
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Affiliation(s)
- Monica Bastawrous
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada.
| | - Amy Jenne
- Department of Chemistry, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada.
| | - Maryam Tabatabaei Anaraki
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada.
| | - André J Simpson
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada.
- Department of Chemistry, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada.
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11
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Simpson AJ, Simpson MJ, Soong R. Environmental Nuclear Magnetic Resonance Spectroscopy: An Overview and a Primer. Anal Chem 2017; 90:628-639. [PMID: 29131590 DOI: 10.1021/acs.analchem.7b03241] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
NMR spectroscopy is a versatile tool for the study of structure and interactions in environmental media such as air, soil, and water as well as monitoring the metabolic responses of living organisms to an ever changing environment. Part review, part perspective, and part tutorial, this Feature is aimed at nonspecialists who are interested in learning more about the potential and impact of NMR spectroscopy in environmental research.
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Affiliation(s)
- André J Simpson
- Environmental NMR Centre and Department of Physical & Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario, Canada , M1C 1A4
| | - Myrna J Simpson
- Environmental NMR Centre and Department of Physical & Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario, Canada , M1C 1A4
| | - Ronald Soong
- Environmental NMR Centre and Department of Physical & Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario, Canada , M1C 1A4
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12
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Sun Z, Zhang C, Chen P, Zhou Q, Hoffmann MR. Impact of humic acid on the photoreductive degradation of perfluorooctane sulfonate (PFOS) by UV/Iodide process. WATER RESEARCH 2017; 127:50-58. [PMID: 29031799 DOI: 10.1016/j.watres.2017.10.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/03/2017] [Accepted: 10/05/2017] [Indexed: 06/07/2023]
Abstract
Iodide photolysis under UV illumination affords an effective method to produce hydrated electrons (eaq-) in aqueous solution. Therefore, UV/Iodide photolysis can be utilized for the reductive degradation of many recalcitrant pollutants. However, the effect of naturally occurring organic matter (NOM) such as humic and fulvic acids (HA/FA), which may impact the efficiency of UV/Iodide photoreduction, is poorly understood. In this study, the UV photoreductive degradation of perfluorooctane sulfonate (PFOS) in the presence of I- and HA is studied. PFOS undergoes a relatively slow direct photoreduction in pure water, a moderate level of degradation via UV/Iodide, but a rapid degradation via UV/Iodide/HA photolysis. After 1.5 h of photolysis, 86.0% of the initial [PFOS] was degraded in the presence of both I- and HA with a corresponding defluorination ratio of 55.6%, whereas only 51.7% of PFOS was degraded with a defluorination ratio of 4.4% via UV/Iodide illumination in the absence of HA. The relative enhancement in the presence of HA in the photodegradation of PFOS can be attributed to several factors: a) HA enhances the effective generation of eaq- due to the reduction of I2, HOI, IO3- and I3- back to I-; b) certain functional groups of HA (i.e., quinones) enhance the electron transfer efficiency as electron shuttles; c) a weakly-bonded association of I- and PFOS with HA increases the reaction probability; and d) absorption of UV photons by HA itself produces eaq-. The degradation and defluorination efficiency of PFOS by UV/Iodide/HA process is dependent on pH and HA concentration. As pH increases from 7.0 to 10.0, the enhancement effect of HA improves significantly. The optimal HA concentration for the degradation of 0.03 mM PFOS is 1.0 mg L-1.
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Affiliation(s)
- Zhuyu Sun
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Chaojie Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Pei Chen
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Qi Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Michael R Hoffmann
- Linde-Robinson Laboratories, California Institute of Technology, Pasadena, CA 91125, United States
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13
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Courtier-Murias D, Michel E, Rodts S, Lafolie F. Novel Experimental-Modeling Approach for Characterizing Perfluorinated Surfactants in Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2602-2610. [PMID: 28165731 DOI: 10.1021/acs.est.6b05671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Soil contamination is still poorly understood and modeled in part because of the difficulties of looking inside the "black box" constituted by soils. Here, we investigated the application of a recently developed 1H NMR technique to 19F NMR relaxometry experiments and utilized the results as inputs for an existing model. This novel approach yields 19F T2 NMR relaxation values of any fluorinated contaminant, which are among the most dangerous contaminants, allowing us to noninvasively and directly monitor their fate in soils. Using this protocol, we quantified the amount of a fluorinated xenobiotic (heptafluorobutyric acid, HFBA) in three different environments in soil aggregate packings and monitored contaminant exchange dynamics between these compartments. A model computing HFBA partition dynamics between different soil compartments showed that these three environments corresponded to HFBA in solution (i) between and (ii) inside the soil aggregates and (iii) to HFBA adsorbed to (or strongly interacting with) the soil constituents. In addition to providing a straightforward way of determining the sorption kinetics of any fluorinated contaminant, this work also highlights the strengths of a combined experimental-modeling approach to unambiguously understand experimental data and more generally to study contaminant fate in soils.
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Affiliation(s)
- Denis Courtier-Murias
- Université Paris-Est, Laboratoire Navier (ENPC-IFSTTAR-CNRS), 77420 Champs-sur-Marne, France
| | - Eric Michel
- EMMAH, INRA, Université d'Avignon et des Pays de Vaucluse, 84000 Avignon, France
| | - Stéphane Rodts
- Université Paris-Est, Laboratoire Navier (ENPC-IFSTTAR-CNRS), 77420 Champs-sur-Marne, France
| | - François Lafolie
- EMMAH, INRA, Université d'Avignon et des Pays de Vaucluse, 84000 Avignon, France
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14
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Longstaffe JG, Courtier-Murias D, Simpson AJ. A nuclear magnetic resonance study of the dynamics of organofluorine interactions with a dissolved humic acid. CHEMOSPHERE 2016; 145:307-313. [PMID: 26692506 DOI: 10.1016/j.chemosphere.2015.11.080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 06/05/2023]
Abstract
A quantitative understanding of the dynamics of the interactions between organofluorine compounds and humic acids will contribute to an improved understanding of the role that Natural Organic Matter plays as a mediator in the fate, transport and distribution of these contaminants in the environment. Here, Nuclear Magnetic Resonance (NMR) spectroscopy-based diffusion measurements are used to estimate the association dynamics between dissolved humic acid and selected organofluorine compounds: pentafluoroaniline, pentafluorophenol, potassium perfluorooctane sulfonate, and perfluorooctanoic acid. Under the conditions used here, the strength of the association with humic acid increases linearly as temperature decreases for all compounds except for perfluorooctanoic acid, which exhibits divergent behavior with a non-linear decrease in the extent of interaction as temperature decreases. A general interaction mechanism controlled largely by desolvation effects is suggested for all compounds examined here except for perfluorooctanoic acid, which exhibits a specific mode of interaction consistent with a proteinaceous binding site. Reverse Heteronuclear Saturation Transfer Difference NMR is used to confirm the identity and nature of the humic acid binding sites.
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Affiliation(s)
- James G Longstaffe
- Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
| | - Denis Courtier-Murias
- Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
| | - Andre J Simpson
- Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
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15
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Masoom H, Courtier-Murias D, Soong R, Maas WE, Fey M, Kumar R, Monette M, Stronks HJ, Simpson MJ, Simpson AJ. From Spill to Sequestration: The Molecular Journey of Contamination via Comprehensive Multiphase NMR. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:13983-13991. [PMID: 26579583 DOI: 10.1021/acs.est.5b03251] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Comprehensive multiphase NMR is a novel NMR technique that permits all components (solutions, gels, and solids) to be studied in unaltered natural samples. In this study a wide range of CMP-NMR interaction and editing-based experiments are combined to follow contaminants (pentafluorophenol (PFP) and perfluorooctanoic acid (PFOA)) from the solution state (after a spill) through the gel-state and finally into the true solid-state (sequestered) in an intact water-swollen soil. Kinetics experiments monitoring each phase illustrate PFOA rapidly transfers from solution to the solid phase while for PFP the process is slower with longer residence times in the solution and gel phase. Interaction-based experiments reveal that PFOA enters the soil via its hydrophobic tails and selectively binds to soil microbial protein. PFP sorption shows less specificity exhibiting interactions with a range of gel and solid soil components with a preference toward aromatics (mainly lignin). The results indicate that in addition to more traditional measurements such as Koc, other factors including the influence of the contaminant on the soil-water interface, specific biological interactions, soil composition (content of lignin, protein, etc.) and physical accessibility/swellability of soil organic components will likely be central to better explaining and predicting the true behavior of contaminants in soil.
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Affiliation(s)
- Hussain Masoom
- Department of Chemistry, University of Toronto , Toronto, Ontario Canada , M1C 1A4
| | | | - Ronald Soong
- Department of Chemistry, University of Toronto , Toronto, Ontario Canada , M1C 1A4
| | - Werner E Maas
- Bruker BioSpin Corp., Billerica, Massachusetts 01821-3991, United States
| | - Michael Fey
- Bruker BioSpin Corp., Billerica, Massachusetts 01821-3991, United States
| | - Rajeev Kumar
- Bruker BioSpin Canada, Milton, Ontario Canada , L9T 1Y6
| | | | | | - Myrna J Simpson
- Department of Chemistry, University of Toronto , Toronto, Ontario Canada , M1C 1A4
| | - André J Simpson
- Department of Chemistry, University of Toronto , Toronto, Ontario Canada , M1C 1A4
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16
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Mazzei P, Piccolo A. Interactions between natural organic matter and organic pollutants as revealed by NMR spectroscopy. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:667-678. [PMID: 25783763 DOI: 10.1002/mrc.4209] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 12/13/2014] [Accepted: 12/16/2014] [Indexed: 06/04/2023]
Abstract
Natural organic matter (NOM) plays a critical role in regulating the transport and the fate of organic contaminants in the environment. NMR spectroscopy is a powerful technique for the investigation of the sorption and binding mechanisms between NOM and pollutants, as well as their mutual chemical transformations. Despite NMR relatively low sensibility but due to its wide versatility to investigating samples in the liquid, gel, and solid phases, NMR application to environmental NOM-pollutants relations enables the achievement of specific and complementary molecular information. This report is a brief outline of the potentialities of the different NMR techniques and pulse sequences to elucidate the interactions between NOM and organic pollutants, with and without their labeling with nuclei that enhance NMR sensitivity.
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Affiliation(s)
- Pierluigi Mazzei
- Centro Interdipartimentale per la Risonanza Magnetica Nucleare per l'Ambiente, l'Agro-Alimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Via Università 100, 80055, Portici, Italy
| | - Alessandro Piccolo
- Centro Interdipartimentale per la Risonanza Magnetica Nucleare per l'Ambiente, l'Agro-Alimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Via Università 100, 80055, Portici, Italy
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17
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Liu Y, Yuan X. Preparation and characterization of a ternary inclusion complex comprising the norfloxacin/β-cyclodextrin complex incorporated in a liposome. J INCL PHENOM MACRO 2015. [DOI: 10.1007/s10847-015-0483-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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Liu J, Mejia Avendaño S. Microbial degradation of polyfluoroalkyl chemicals in the environment: a review. ENVIRONMENT INTERNATIONAL 2013; 61:98-114. [PMID: 24126208 DOI: 10.1016/j.envint.2013.08.022] [Citation(s) in RCA: 276] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 08/22/2013] [Accepted: 08/26/2013] [Indexed: 05/20/2023]
Abstract
Polyfluoroalkyl chemicals containing perfluoroalkyl moieties have been widely used in numerous industrial and commercial applications. Many polyfluoroalkyl chemicals are potential perfluoroalkyl acid (PFAA) precursors. When they are released to the environment, abiotic and microbial degradation of non-fluorinated functionalities, polyfluoroalkyl and perfluoroalkyl moieties can result in perfluoroalkyl carboxylic (PFCAs) and sulfonic acids (PFSAs), such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). These highly persistent and ubiquitously detected PFAAs are the subjects of many regulations and actions due to their toxic profiles. In order to confidently evaluate the environmental fate and effects of these precursors and their links to PFSAs and PFCAs, we present the review into the environmental biodegradability studies carried out with microbial culture, activated sludge, soil and sediment in the past decade. First, we propose that the knowledge gap caused by the lack of direct detection of precursor chemicals in environmental samples can be bridged by laboratory investigations of important precursors such as fluorotelomer-based compounds and perfluoroalkane sulfonamido derivatives. Then we evaluate the experimental setups and methodologies, sampling and sample preparation methods, and analytical techniques that have been successfully applied. Third, we provide the most updated knowledge on quantitative and qualitative relationships between precursors and PFSAs or PFCAs, microbial degradation pathways, half-lives of precursors, defluorination potential, and novel degradation intermediates and products. In the end, we identify knowledge gaps and suggest research directions with regard to future biodegradation studies, environmental monitoring and ecotoxicological assessment of perfluoroalkyl and polyfluoroalkyl chemicals.
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Affiliation(s)
- Jinxia Liu
- Department of Civil Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada.
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19
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Masoom H, Courtier-Murias D, Farooq H, Soong R, Simpson MJ, Maas W, Kumar R, Monette M, Stronks H, Simpson AJ. Rapid estimation of nuclear magnetic resonance experiment time in low-concentration environmental samples. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:129-136. [PMID: 23065696 DOI: 10.1002/etc.2028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 07/28/2012] [Accepted: 08/23/2012] [Indexed: 06/01/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is an essential tool for studying environmental samples but is often hindered by low sensitivity, especially for the direct detection of nuclei such as(13) C. In very heterogeneous samples with NMR nuclei at low abundance, such as soils, sediments, and air particulates, it can take days to acquire a conventional(13) C spectrum. The present study describes a prescreening method that permits the rapid prediction of experimental run time in natural samples. The approach focuses the NMR chemical shift dispersion into a single spike, and, even in samples with extremely low carbon content, the spike can be observed in two to three minutes, or less. The intensity of the spike is directly proportional to the total concentration of nuclei of interest in the sample. Consequently, the spike intensity can be used as a powerful prescreening method that answers two key questions: (1) Will this sample produce a conventional NMR spectrum? (2) How much instrument time is required to record a spectrum with a specific signal-to-noise (S/N) ratio? The approach identifies samples to avoid (or pretreat) and permits additional NMR experiments to be performed on samples producing high-quality NMR data. Applications in solid- and liquid-state(13) C NMR are demonstrated, and it is shown that the technique is applicable to a range of nuclei.
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Affiliation(s)
- Hussain Masoom
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
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20
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Longstaffe JG, Courtier-Murias D, Simpson AJ. The pH-dependence of organofluorine binding domain preference in dissolved humic acid. CHEMOSPHERE 2013; 90:270-275. [PMID: 22863060 DOI: 10.1016/j.chemosphere.2012.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/03/2012] [Accepted: 07/05/2012] [Indexed: 06/01/2023]
Abstract
In this study we explore the relationship between solution pH and the distribution of the binding interactions at different domains of a dissolved humic acid (HA) for three xenobiotics: pentafluoroaniline (PFA), pentafluorophenol (PFP), and hexafluorobenzene (HFB). The components of HA where xenobiotic interactions occur are identified using the (1)H{(19)F} Reverse Heteronuclear Saturation Transfer Difference (RHSTD) Nuclear Magnetic Resonance (NMR) spectroscopy experiment. At low pH, PFA and PFP interact preferentially with aromatic components of HA. Increasing pH reduces this preference. Conversely, HFB interacts with all components of HA equally, across the entire pH range. The possible roles of both aromatic-specific interactions and conformational changes of HA behind these observations are explored. It is shown that T-oriented π-π interactions at π-electron accepting HA structures are slightly stronger for PFA and PFP than for HFB. Using DOSY NMR it is shown that the pH-dependence of the interactions is correlated with changes in the conformation of the carbohydrate components of HA rather than with the aromatic components. It is argued that the observed preference for aromatic HA is caused by restricted access to the non-aromatic components of HA at low pH. These HA components form tightly bound hydrophobic domains due to strong inter- and intra-molecular hydrogen bonds. At high pH, these structures open up, making them more available for interactions with polar compounds.
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Affiliation(s)
- James G Longstaffe
- Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4.
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21
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Simpson AJ, Simpson MJ, Soong R. Nuclear magnetic resonance spectroscopy and its key role in environmental research. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:11488-11496. [PMID: 22909253 DOI: 10.1021/es302154w] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Nuclear magnetic resonance (NMR) is arguably the most powerful and versatile tool in modern science. It has the capability to solve complex structures and interactions in situ even in complex heterogeneous multiphase samples such as soil, plants, and tissues. NMR has vast potential in environmental research and can provide insight into a diverse range of environmental processes at the molecular level be it identifying the binding site in human blood for a specific contaminant or the compositional dynamics of soil with climate change. Modern NMR-based metabonomics is elucidating contaminant toxicity and toxic mode of action rapidly and at sub lethal concentrations. Combined modern NMR approaches provide a powerful framework to better understand carbon cycling and sustainable agriculture, as well as contaminant fate, bioavailability, toxicity, sequestration, and remediation.
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Affiliation(s)
- Andre J Simpson
- Environmental NMR Centre, Department of Chemistry, University of Toronto, Toronto, Canada.
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22
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Longstaffe JG, Courtier-Murias D, Soong R, Simpson MJ, Maas WE, Fey M, Hutchins H, Krishnamurthy S, Struppe J, Alaee M, Kumar R, Monette M, Stronks HJ, Simpson AJ. In-situ molecular-level elucidation of organofluorine binding sites in a whole peat soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:10508-10513. [PMID: 22946434 DOI: 10.1021/es3026769] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The chemical nature of xenobiotic binding sites in soils is of vital importance to environmental biogeochemistry. Interactions between xenobiotics and the naturally occurring organic constituents of soils are strongly correlated to environmental persistence, bioaccessibility, and ecotoxicity. Nevertheless, because of the complex structural and chemical heterogeneity of soils, studies of these interactions are most commonly performed indirectly, using correlative methods, fractionation, or chemical modification. Here we identify the organic components of an unmodified peat soil where some organofluorine xenobiotic compounds interact using direct molecular-level methods. Using (19)F→(1)H cross-polarization magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy, the (19)F nuclei of organofluorine compounds are used to induce observable transverse magnetization in the (1)H nuclei of organic components of the soil with which they interact after sorption. The observed (19)F→(1)H CP-MAS spectra and dynamics are compared to those produced using model soil organic compounds, lignin and albumin. It is found that lignin-like components can account for the interactions observed in this soil for heptafluoronaphthol (HFNap) while protein structures can account for the interactions observed for perfluorooctanoic acid (PFOA). This study employs novel comprehensive multi-phase (CMP) NMR technology that permits the application of solution-, gel-, and solid-state NMR experiments on intact soil samples in their swollen state.
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Affiliation(s)
- James G Longstaffe
- Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada, M1C 1A4
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23
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Courtier-Murias D, Farooq H, Masoom H, Botana A, Soong R, Longstaffe JG, Simpson MJ, Maas WE, Fey M, Andrew B, Struppe J, Hutchins H, Krishnamurthy S, Kumar R, Monette M, Stronks HJ, Hume A, Simpson AJ. Comprehensive multiphase NMR spectroscopy: basic experimental approaches to differentiate phases in heterogeneous samples. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 217:61-76. [PMID: 22425441 DOI: 10.1016/j.jmr.2012.02.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 02/15/2012] [Indexed: 05/16/2023]
Abstract
Heterogeneous samples, such as soils, sediments, plants, tissues, foods and organisms, often contain liquid-, gel- and solid-like phases and it is the synergism between these phases that determine their environmental and biological properties. Studying each phase separately can perturb the sample, removing important structural information such as chemical interactions at the gel-solid interface, kinetics across boundaries and conformation in the natural state. In order to overcome these limitations a Comprehensive Multiphase-Nuclear Magnetic Resonance (CMP-NMR) probe has been developed, and is introduced here, that permits all bonds in all phases to be studied and differentiated in whole unaltered natural samples. The CMP-NMR probe is built with high power circuitry, Magic Angle Spinning (MAS), is fitted with a lock channel, pulse field gradients, and is fully susceptibility matched. Consequently, this novel NMR probe has to cover all HR-MAS aspects without compromising power handling to permit the full range of solution-, gel- and solid-state experiments available today. Using this technology, both structures and interactions can be studied independently in each phase as well as transfer/interactions between phases within a heterogeneous sample. This paper outlines some basic experimental approaches using a model heterogeneous multiphase sample containing liquid-, gel- and solid-like components in water, yielding separate (1)H and (13)C spectra for the different phases. In addition, (19)F performance is also addressed. To illustrate the capability of (19)F NMR soil samples, containing two different contaminants, are used, demonstrating a preliminary, but real-world application of this technology. This novel NMR approach possesses a great potential for the in situ study of natural samples in their native state.
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Affiliation(s)
- Denis Courtier-Murias
- Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, ON, Canada M1C 1A4
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24
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Wang N, Buck RC, Szostek B, Sulecki LM, Wolstenholme BW. 5:3 Polyfluorinated acid aerobic biotransformation in activated sludge via novel "one-carbon removal pathways". CHEMOSPHERE 2012; 87:527-534. [PMID: 22264858 DOI: 10.1016/j.chemosphere.2011.12.056] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/20/2011] [Accepted: 12/22/2011] [Indexed: 05/27/2023]
Abstract
The polyfluorinated carboxylic acids 5:3 acid (C(5)F(11)CH(2)CH(2)CO(2)H) and 7:3 acid (C(7)F(15)CH(2)CH(2)CO(2)H) are major products from 6:2 FTOH (C(6)F(13)CH(2)CH(2)OH) and 8:2 FTOH (C(8)F(17)CH(2)CH(2)OH) aerobic biotransformation, respectively. The 5:3 and 7:3 acids were dosed into domestic WWTP activated sludge for 90 d to determine their biodegradability. The 7:3 acid aerobic biodegradability was low, only 1.7 mol% conversion to perfluoroheptanoic acid (PFHpA), whereas no transformation was observed previously in soil. In stark contrast, 5:3 acid aerobic biodegradability was enhanced 10 times in activated sludge compared to soil. The 5:3 acid was not activated by acyl CoEnzyme A (CoA) synthetase, a key step required for further α- or ß-oxidation. Instead, 5:3 acid was directly converted to 4:3 acid (C(4)F(9)CH(2)CH(2)CO(2)H, 14.2 mol%) and 3:3 acid (C(3)F(7)CH(2)CH(2)CO(2)H, 0.9 mol%) via "one-carbon removal pathways". The 5:3 acid biotransformation also yielded perfluoropentanoic acid (PFPeA, 5.9 mol%) and perfluorobutanoic acid (PFBA, 0.8 mol%). This is the first report to identify key biotransformation intermediates which demonstrate novel one-carbon removal pathways with sequential removal of CF(2) groups. Identified biotransformation intermediates (10.2 mol% in sum) were 5:3 Uacid, α-OH 5:3 acid, 5:2 acid, and 5:2 Uacid. The 5:2 Uacid and 5:2 acid are novel intermediates identified for the first time which confirm the proposed pathways. In the biodegradation pathways, the genesis of the one carbon removal is CO(2) elimination from α-OH 5:3 acid. These results suggest that there are enzymatic mechanisms available in the environment that can lead to 6:2 FTOH and 5:3 acid mineralization. The dehydrogenation from 5:3 acid to 5:3 Uacid was the rate-limiting enzymatic step for 5:3 acid conversion to 4:3 acid.
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Affiliation(s)
- Ning Wang
- E.I. du Pont De Nemours & Company, Inc., Wilmington, DE, USA.
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25
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Longstaffe JG, Simpson AJ. Understanding solution-state noncovalent interactions between xenobiotics and natural organic matter using 19F/1H heteronuclear saturation transfer difference nuclear magnetic resonance spectroscopy. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:1745-1753. [PMID: 21538490 DOI: 10.1002/etc.560] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 03/03/2011] [Accepted: 04/07/2011] [Indexed: 05/30/2023]
Abstract
A combination of forward and reverse heteronuclear ((19)F/(1)H) saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopic techniques were applied to characterize the noncovalent interactions between perfluorinated aromatic xenobiotics and dissolved humic acid. These NMR techniques produce detailed molecular-level descriptions of weak noncovalent associations between components in complex environmental mixtures, allowing the mechanisms underlying these interactions to be explored; (19)F observed heteronuclear STD (H-STD) is used to describe the average molecular orientation of the xenobiotics during their interactions with humic acid, whereas (1)H observed reverse-heteronuclear STD (RH-STD) is used to both identify and quantify preferences exhibited by xenobiotics for interactions at different types of humic acid moieties. First, by using H-STD, it is shown that selected aromatic organofluorides orient with their nonfluorine functional groups (OH, NH(2), and COOH) directed away from humic acid during the interactions, suggesting that these functional groups are not specifically involved. Second, the RH-STD experiment is shown to be sensitive to subtle differences in preferred interaction sites in humic acid and is used here to demonstrate preferential interactions at aromatic humic acid sites for selected aromatic xenobiotics, C(10)F(7)OH, and C(6)F(4)X(2), (where X = F, OH, NH(2), NO(2), or COOH), that can be predicted from the electrostatic potential density maps of the xenobiotic.
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26
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Wang N, Liu J, Buck RC, Korzeniowski SH, Wolstenholme BW, Folsom PW, Sulecki LM. 6:2 fluorotelomer sulfonate aerobic biotransformation in activated sludge of waste water treatment plants. CHEMOSPHERE 2011; 82:853-8. [PMID: 21112609 DOI: 10.1016/j.chemosphere.2010.11.003] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 10/29/2010] [Accepted: 11/01/2010] [Indexed: 05/03/2023]
Abstract
The aerobic biotransformation of 6:2 FTS salt [F(CF2)6CH2CH2SO3- K+] was determined in closed bottles for 90d in diluted activated sludge from three waste water treatment plants (WWTPs) to compare its biotransformation potential with that of 6:2 FTOH [F(CF2)6CH2CH2OH]. The 6:2 FTS biotransformation was relatively slow, with 63.7% remaining at day 90 and all observed transformation products together accounting for 6.3% of the initial 6:2 FTS applied. The overall mass balance (6:2 FTS plus observed transformation products) at day 90 in live and sterile treatments averaged 70% and 94%, respectively. At day 90, the stable transformation products observed were 5:3 acid [F(CF2)5CH2CH2COOH, 0.12%], PFBA [F(CF2)3COOH, 0.14%], PFPeA [F(CF2)4COOH, 1.5%], and PFHxA [F(CF2)5COOH 1.1%]. In addition, 5:2 ketone [F(CF2)5C(O)CH3] and 5:2 sFTOH [F(CF2)5CH(OH)CH3] together accounted for 3.4% at day 90. The yield of all the stable transformation products noted above (2.9%) was 19 times lower than that of 6:2 FTOH in aerobic soil. Thus 6:2 FTS is not likely to be a major source of PFCAs and polyfluorinated acids in WWTPs. 6:2 FTOH, 6:2 FTA [F(CF2)6CH2COOH], and PFHpA [F(CF2)6COOH] were not observed during the 90-d incubation. 6:2 FTS primary biotransformation bypassed 6:2 FTOH to form 6:2 FTUA [F(CF2)5CF=CHCOOH], which was subsequently degraded via pathways similar to 6:2 FTOH biotransformation. A substantial fraction of initially dosed 6:2 FTS (24%) may be irreversibly bound to diluted activated sludge catalyzed by microbial enzymes. The relatively slow 6:2 FTS degradation in activated sludge may be due to microbial aerobic de-sulfonation of 6:2 FTS, required for 6:2 FTS further biotransformation, being a rate-limiting step in microorganisms of activated sludge in WWTPs.
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Affiliation(s)
- Ning Wang
- E.I. du Pont De Nemours, Co., Inc., Wilmington, DE, USA.
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