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Barreto MSC, Elzinga EJ, Kubicki JD, Sparks DL. A multi-scale assessment of the impact of salinity on the desorption of chromate from hematite: Sea level rise implications. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133041. [PMID: 38043423 DOI: 10.1016/j.jhazmat.2023.133041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/08/2023] [Accepted: 11/17/2023] [Indexed: 12/05/2023]
Abstract
The solubility and transport of Cr(VI) is primarily controlled by adsorption-desorption reactions at the surfaces of soil minerals such as iron oxides. Environmental properties such as pH, ionic strength, and ion competition are expected to affect the mobility and fate of Cr(VI). Sea level rise (SLR), and consequent seawater intrusion, is creating a new biogeochemical soil environment at coastal margins, potentially impacting Cr(VI) retention at contaminated sites. We employed in-situ ATR-FTIR spectroscopy and DFT calculations to investigate at the molecular level the adsorption of Cr(VI) on the hematite surface and its desorption by sulfate, as a function of pH and ionic strength. We further used a batch experiment to assess Cr(VI) desorption at varying artificial seawater (ASW) concentrations. IR results demonstrate the complexity of Cr(VI) adsorption, showing a combination of monodentate inner-sphere complexation at high pH and dichromate outer-sphere (∼75%) at low pH. The Cr(VI)-complexes exhibited desorption induced by increasing pH values (58% of desorption) and sulfate competition (∼40% desorption). ASW desorbed ∼20% more Cr(VI), even at just 1% concentration. Our findings provide insight into Cr(VI)-adsorption complexation that controls the retention and remobilization of Cr(VI) on Fe-oxide minerals. The results point to an elevated risk of Cr(VI) mobilization in contaminated soils affected by SLR.
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Affiliation(s)
| | - Evert J Elzinga
- Department of Earth & Environmental Sciences, Rutgers University, Newark, NJ, USA
| | - James D Kubicki
- Department of Earth, Environmental & Resource Sciences, The University of Texas at El Paso, El Paso, TX, USA
| | - Donald L Sparks
- Department of Plant & Soil Sciences, University of Delaware, Newark, DE, USA
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2
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Mouco-Novegil BA, Hernández-Córdoba M, López-García I. Improvement in the Chromium(VI)-Diphenylcarbazide Determination Using Cloud Point Microextraction; Speciation of Chromium at Low Levels in Water Samples. Molecules 2023; 29:153. [PMID: 38202735 PMCID: PMC10779736 DOI: 10.3390/molecules29010153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/12/2024] Open
Abstract
A reliable, rapid, and low-cost procedure for determining very low concentrations of hexavalent chromium (Cr) in water is discussed. The procedure is based in the classical reaction of Cr6+ with diphenylcarbazide. Once this reaction has taken place, sodium dodecylsulfate is added to obtain an ion-pair, and Triton X-114 is incorporated. Next, the heating of the mixture allows two phases that can be separated by centrifugation to be obtained in a cloud point microextraction (CPE) process. The coacervate contains all the Cr6+ originally present in the water sample, so that the measurement by molecular absorption spectrophotometry allows the concentration of the metal to be calculated. No harmful organic solvents are required. The discrimination of hexavalent and trivalent forms is achieved by including an oxidation stage with Ce4+. To take full advantage of the pre-concentration effect inherent to the coacervation process, as well as to minimize reagent consumption and waste generation, a portable mini-spectrophotometer which is compatible with microvolumes of liquid samples is used. The preconcentration factor is 415 and a chromium concentration as low as 0.02 µg L-1 can be detected. The procedure shows a good reproducibility (relative standard deviation close to 3%).
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Affiliation(s)
| | | | - Ignacio López-García
- Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence “Campus Mare-Nostrum”, University of Murcia, E-30100 Murcia, Spain; (B.A.M.-N.); (M.H.-C.)
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3
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Al Isawi WA, Hartman CK, Singh P, Zeller M, Mezei G. Chromate Incarceration by Nanojars and Its Removal from Water by Liquid-Liquid Extraction. Inorg Chem 2023; 62:5716-5728. [PMID: 36961999 DOI: 10.1021/acs.inorgchem.3c00262] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
The unprecedented liquid-liquid extraction of the dinegative chromate ion (CrO42-) from neutral aqueous solutions into aliphatic hydrocarbon solvents using nanojars as extraction agents is demonstrated. Transferring chromate from water into an organic solvent is extremely challenging due to its large hydration energy (ΔGh° = -950 kJ/mol) and strong oxidizing ability. Owing to their highly hydrophilic anion binding pockets lined by a multitude of hydrogen bond donor OH groups, neutral nanojars of the formula [cis-CuII(μ-OH)(μ-4-Rpz)]n (n = 27-33; pz = pyrazolate anion; R = H or n-octyl) strongly bind the CrO42- ion and efficiently transfer it from water into n-heptane or C11 - C13 isoalkanes (when R = n-octyl). The extracted chromate can easily be recovered from the organic layer by stripping with an aqueous acid solution. Electrospray ionization mass spectrometric, UV-vis and paramagnetic 1H NMR spectroscopic, X-ray crystallographic, and thermal stability studies in solution and chemical stability studies toward NH3, methanol, and Ba2+ ions are employed to explore the binding of the CrO42- ion by nanojars. Titration of carbonate nanojars [CO3 ⊂ {Cu(OH)(pz)}n]2- with H2CrO4 leads to anion exchange and the formation of chromate nanojars [CrO4 ⊂ {Cu(OH)(pz)}n]2-. Details of chromate binding by H-bonding based on single-crystal structures of (Bu4N)2[CrO4 ⊂ {Cu(OH)(pz)}28], four pseudopolymorphs of (Bu4N)2[CrO4 ⊂ {Cu(OH)(pz)}31], and also the methoxy-substituted derivative (Bu4N)2[CrO4 ⊂ {Cu31(OH)30(OCH3)(pz)31}] are presented.
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Affiliation(s)
- Wisam A Al Isawi
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States
| | - Christian K Hartman
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States
| | - Pooja Singh
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States
| | - Matthias Zeller
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Gellert Mezei
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States
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Guo J, Ye S, Li H, Chen Y, Liu H, Song Y, Peng X, Zhou F, Song J, Qu J. Novel fluorescent probes based on nitrogen–sulfur co-doped carbon dots for chromium ion detection. NEW J CHEM 2021. [DOI: 10.1039/d0nj06178f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In this work, novel carbon dots codoped with nitrogen and sulfur (NSCDs) were used as fluorescent probes to detect Cr3+.
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5
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Muthwa SF, Makhanya TR, Mlambo M, Shumbula NP, Shumbula PM, Onwubu SC, Moloto N, Gengan RM, Mdluli PS. Synthesis and characterization of 3-(p-tolyl)-2,3-dihydropyrazolo[3,4-b]indole-1(4H)-carbothioamide functionalized gold nanoparticles for the CIEL∗a∗b∗/Yxy colorimetric detection of Cr(VI). J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.127985] [Citation(s) in RCA: 1] [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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6
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Desai ML, Jha S, Basu H, Saha S, Singhal RK, Kailasa SK. Simple hydrothermal approach for synthesis of fluorescent molybdenum disulfide quantum dots: Sensing of Cr 3+ ion and cellular imaging. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 111:110778. [PMID: 32279756 DOI: 10.1016/j.msec.2020.110778] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/15/2020] [Accepted: 02/25/2020] [Indexed: 11/26/2022]
Abstract
Nowadays, fluorescent molybdenum disulfide quantum dots (MoS2 QDs) have proven to be potential candidates in the sensing and bioimaging areas owing to their exceptional intrinsic characteristics. Here, a simple hydrothermal strategy was explored for the preparation of MoS2 QDs using ammonium heptamolybdate and 6-mercaptopurine (6-MP) as precursors. The emission peak of MoS2 QDs was significantly quenched in the presence Cr3+ ion due to the selective surface chemistry on the surfaces of MoS2 QDs. The designed fluorescent MoS2 QDs showed a linear fluorescence quenching response with increasing concentration of Cr3+ ion (0.1-10 μM), allowing to detect Cr3+ ion even at 0.08 μM. This fluorescent MoS2 QDs were utilized for the quantification of Cr3+ ion in real samples (water and biological samples). Interestingly, the synthesized MoS2 QDs exhibited negligible cytotoxicity on NRK cells and acted as good candidates for imaging of Trichoderma viride fungal cells.
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Affiliation(s)
- Mittal L Desai
- Applied Chemistry Department, S. V. National Institute of Technology, Surat 395 007, India
| | - Sanjay Jha
- Gujarat Agricultural Biotechnology Institute, Navsari Agricultural University, Surat 395007, India
| | - Hirakendu Basu
- Analytical Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085, India
| | - Sudeshna Saha
- Analytical Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085, India
| | - Rakesh Kumar Singhal
- Analytical Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085, India
| | - Suresh Kumar Kailasa
- Applied Chemistry Department, S. V. National Institute of Technology, Surat 395 007, India.
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7
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Zhu X, Deng Y, Li P, Yuan D, Ma J. Automated syringe-pump-based flow-batch analysis for spectrophotometric determination of trace hexavalent chromium in water samples. Microchem J 2019. [DOI: 10.1016/j.microc.2018.12.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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8
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Calderilla C, Maya F, Cerdà V, Leal LO. 3D printed device for the automated preconcentration and determination of chromium (VI). Talanta 2018; 184:15-22. [PMID: 29674027 DOI: 10.1016/j.talanta.2018.02.065] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/24/2018] [Accepted: 02/13/2018] [Indexed: 10/18/2022]
Abstract
A 3D printed device for the fully automated disk-based solid-phase extraction (SPE) of Cr (VI) from water samples has been fabricated. The compatibility of the use of organic solvents for analyte elution with 3D printed flow devices based on polymers fabricated using stereolithography has been evaluated. The developed methodology comprises the complexation of Cr (VI) with 1, 5-diphenylcarbazide (DPC) in acidic medium and the subsequent retention of the complex in a SBD-RPS disk contained within the 3D printed device. A multisyringe flow injection analysis system with online spectrophotometric detection has been used for the automation of the method. The fabricated 3D printed device integrates the different components of the flow analysis manifold, including connectors and mixers, being a powerful approach towards the reproducible construction of highly integrated flow-based manifolds. The extracted Cr (VI)-DPC complex is eluted with a mixture of methanol- sulfuric acid and quantified at 540 nm. The effect on the analytical signal and the optimization of variables were evaluated using multivariate and univariate techniques. A detection limit of 1 ng Cr (VI) and a linear working range of 3.2-600 ng Cr (VI) were obtained using a sample volume of 2 ml. The intra-day and inter-day RSDs were 4.8% (10 µg L-1, n = 12) and 3.4% (n = 5, different day with a different disk), respectively. The applicability of the fabricated 3D printed device has been proved by the determination of Cr (VI) in groundwater, surface water and leachates.
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Affiliation(s)
- Carlos Calderilla
- Laboratory of Environmental Analytical Chemistry-LQA2, University of the Balearic Islands, Cra.Valldemossa km 7.5, 07122 Palma de Mallorca, Spain; Environment and Energy Department, Advanced Materials Research Center, Miguel de Cervantes 120, 31136 Chihuahua, Mexico
| | - Fernando Maya
- Laboratory of Environmental Analytical Chemistry-LQA2, University of the Balearic Islands, Cra.Valldemossa km 7.5, 07122 Palma de Mallorca, Spain.
| | - Víctor Cerdà
- Laboratory of Environmental Analytical Chemistry-LQA2, University of the Balearic Islands, Cra.Valldemossa km 7.5, 07122 Palma de Mallorca, Spain
| | - Luz O Leal
- Environment and Energy Department, Advanced Materials Research Center, Miguel de Cervantes 120, 31136 Chihuahua, Mexico
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9
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Wang D, Jiao F, Qin W, Wang X. Effect of surface oxidation on the flotation separation of chalcopyrite and galena using sodium humate as depressant. SEP SCI TECHNOL 2017. [DOI: 10.1080/01496395.2017.1405042] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Daowei Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha Hunan, China
| | - Fen Jiao
- School of Minerals Processing and Bioengineering, Central South University, Changsha Hunan, China
| | - Wenqing Qin
- School of Minerals Processing and Bioengineering, Central South University, Changsha Hunan, China
| | - Xingjie Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha Hunan, China
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10
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Underway analysis of nanomolar dissolved reactive phosphorus in oligotrophic seawater with automated on-line solid phase extraction and spectrophotometric system. Anal Chim Acta 2017; 950:80-87. [DOI: 10.1016/j.aca.2016.11.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/09/2016] [Accepted: 11/11/2016] [Indexed: 12/11/2022]
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11
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Guo JF, Huo DQ, Yang M, Hou CJ, Li JJ, Fa HB, Luo HB, Yang P. Colorimetric detection of Cr (VI) based on the leaching of gold nanoparticles using a paper-based sensor. Talanta 2016; 161:819-825. [DOI: 10.1016/j.talanta.2016.09.032] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/07/2016] [Accepted: 09/11/2016] [Indexed: 01/07/2023]
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12
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Dou M, Lopez J, Rios M, Garcia O, Xiao C, Eastman M, Li X. A fully battery-powered inexpensive spectrophotometric system for high-sensitivity point-of-care analysis on a microfluidic chip. Analyst 2016; 141:3898-903. [PMID: 27143408 DOI: 10.1039/c6an00370b] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A cost-effective b[combining low line]a[combining low line]ttery-powered s[combining low line]pectrophotometric s[combining low line]ystem (BASS) was developed for quantitative point-of-care (POC) analysis on a microfluidic chip. By using methylene blue as a model analyte, we first compared the performance of the BASS with a commercial spectrophotometric system, and further applied the BASS for loop-mediated isothermal amplification (LAMP) detection and subsequent quantitative nucleic acid analysis which exhibited a comparable limit of detection to that of Nanodrop. Compared to the commercial spectrophotometric system, our spectrophotometric system is lower-cost, consumes less reagents, and has higher detection sensitivity. Most importantly, it does not rely on external power supplies. All these features make our spectrophotometric system highly suitable for a variety of POC analyses, such as field detection.
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Affiliation(s)
- Maowei Dou
- Department of Chemistry, University of Texas at El Paso, 500 West University Ave, El Paso, Texas 79968, USA
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13
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Sereshti H, Vasheghani Farahani M, Baghdadi M. Trace determination of chromium(VI) in environmental water samples using innovative thermally reduced graphene (TRG) modified SiO2 adsorbent for solid phase extraction and UV–vis spectrophotometry. Talanta 2016; 146:662-9. [DOI: 10.1016/j.talanta.2015.06.051] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/18/2015] [Accepted: 06/19/2015] [Indexed: 11/30/2022]
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14
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Bagtash M, Yamini Y, Tahmasebi E, Zolgharnein J, Dalirnasab Z. Magnetite nanoparticles coated with tannic acid as a viable sorbent for solid-phase extraction of Cd2+, Co2+ and Cr3+. Mikrochim Acta 2015. [DOI: 10.1007/s00604-015-1667-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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15
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Gałuszka A, Migaszewski ZM, Namieśnik J. Moving your laboratories to the field--Advantages and limitations of the use of field portable instruments in environmental sample analysis. ENVIRONMENTAL RESEARCH 2015; 140:593-603. [PMID: 26051907 DOI: 10.1016/j.envres.2015.05.017] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 05/05/2015] [Accepted: 05/16/2015] [Indexed: 05/21/2023]
Abstract
The recent rapid progress in technology of field portable instruments has increased their applications in environmental sample analysis. These instruments offer a possibility of cost-effective, non-destructive, real-time, direct, on-site measurements of a wide range of both inorganic and organic analytes in gaseous, liquid and solid samples. Some of them do not require the use of reagents and do not produce any analytical waste. All these features contribute to the greenness of field portable techniques. Several stationary analytical instruments have their portable versions. The most popular ones include: gas chromatographs with different detectors (mass spectrometer (MS), flame ionization detector, photoionization detector), ultraviolet-visible and near-infrared spectrophotometers, X-ray fluorescence spectrometers, ion mobility spectrometers, electronic noses and electronic tongues. The use of portable instruments in environmental sample analysis gives a possibility of on-site screening and a subsequent selection of samples for routine laboratory analyses. They are also very useful in situations that require an emergency response and for process monitoring applications. However, quantification of results is still problematic in many cases. The other disadvantages include: higher detection limits and lower sensitivity than these obtained in laboratory conditions, a strong influence of environmental factors on the instrument performance and a high possibility of sample contamination in the field. This paper reviews recent applications of field portable instruments in environmental sample analysis and discusses their analytical capabilities.
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Affiliation(s)
- Agnieszka Gałuszka
- Geochemistry and the Environment Division, Institute of Chemistry, Jan Kochanowski University, 15G Świętokrzyska St., 25-406 Kielce, Poland.
| | - Zdzisław M Migaszewski
- Geochemistry and the Environment Division, Institute of Chemistry, Jan Kochanowski University, 15G Świętokrzyska St., 25-406 Kielce, Poland
| | - Jacek Namieśnik
- Department of Analytical Chemistry, Chemical Faculty, Gdańsk University of Technology (GUT), 11/12 G. Narutowicz St., 80-233 Gdańsk, Poland
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Sereshti H, Amini F, Najarzadekan H. Electrospun polyethylene terephthalate (PET) nanofibers as a new adsorbent for micro-solid phase extraction of chromium(vi) in environmental water samples. RSC Adv 2015. [DOI: 10.1039/c5ra14788c] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An SPME method based on electrospun PET nanofibers coupled with UV-Vis spectrophotometry for the detection of Cr(vi) in water.
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Affiliation(s)
- Hassan Sereshti
- Department of Chemistry
- Faculty of Science
- University of Tehran
- Tehran
- Iran
| | - Farzaneh Amini
- Department of Chemistry
- Faculty of Science
- University of Tehran
- Tehran
- Iran
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17
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Ma J, Yuan D, Byrne RH. Flow injection analysis of trace chromium (VI) in drinking water with a liquid waveguide capillary cell and spectrophotometric detection. ENVIRONMENTAL MONITORING AND ASSESSMENT 2014; 186:367-373. [PMID: 23943244 DOI: 10.1007/s10661-013-3381-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 07/31/2013] [Indexed: 06/02/2023]
Abstract
Hexavalent chromium (Cr(VI)) is an acknowledged hazardous material in drinking waters. As such, effective monitoring and assessment of the risks posed by Cr(VI) are important analytical objectives for both human health and environmental science. However, because of the lack of highly sensitive, rapid, and simple procedures, a relatively limited number of studies have been carried out in this field. Here we report a simple and sensitive analytical procedure of flow injection analysis (FIA) for sub-nanomolar Cr(VI) in drinking water samples with a liquid core waveguide capillary cell (LWCC). The procedure is based on a highly selective reaction between 1, 5-diphenylcarbazide and Cr(VI) under acidic conditions. The optimized experimental parameters included reagent concentrations, injection volume, length of mixing coil, and flow rate. Measurements at 540 nm, and a 650-nm reference wavelength, produced a 0.12-nM detection limit. Relative standard deviations for 1, 2, and 10 nM samples were 5.6, 3.6, and 0.72 % (n = 9), and the analysis time was <2 min sample(-1). The effects of salinity and interfering ions, especially Fe(III), were evaluated. Using the FIA-LWCC method, different sources of bottled waters and tap waters were examined. The Cr(VI) concentrations of the bottled waters ranged from the detection limit to ∼20 nM, and tap waters collected from the same community supply had Cr(VI) concentration around 14 nM.
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Affiliation(s)
- Jian Ma
- State Key Laboratory of Marine Environmental Science, College of Environment and Ecology, Xiamen University, Xiamen, Fujian, China, 361005,
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18
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Liu X, Byrne RH, Adornato L, Yates KK, Kaltenbacher E, Ding X, Yang B. In situ spectrophotometric measurement of dissolved inorganic carbon in seawater. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:11106-11114. [PMID: 23991621 DOI: 10.1021/es4014807] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Autonomous in situ sensors are needed to document the effects of today's rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator's molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg(-1) and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.
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Affiliation(s)
- Xuewu Liu
- College of Marine Science, University of South Florida , 140 7th Avenue S., St. Petersburg, Florida 33701, United States
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19
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Henríquez C, Horstkotte B, Solich P, Cerdà V. In-syringe magnetic-stirring-assisted liquid–liquid microextraction for the spectrophotometric determination of Cr(VI) in waters. Anal Bioanal Chem 2013; 405:6761-9. [DOI: 10.1007/s00216-013-7111-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 05/13/2013] [Accepted: 05/31/2013] [Indexed: 10/26/2022]
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20
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Facile preparation of glutathione-stabilized gold nanoclusters for selective determination of chromium (III) and chromium (VI) in environmental water samples. Anal Chim Acta 2013; 770:140-6. [PMID: 23498696 DOI: 10.1016/j.aca.2013.01.042] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 01/14/2013] [Accepted: 01/20/2013] [Indexed: 11/22/2022]
Abstract
A novel method for selective determination of Cr(III) and Cr(VI) in environmental water samples was developed based on target-induced fluorescence quenching of glutathione-stabilized gold nanoclusters (GSH-Au NCs). Fluorescent GSH-Au NCs were synthesized by a one-step approach employing GSH as reducing/protecting reagent. It was found that Cr(III) and Cr(VI) showed pH-dependent fluorescence quenching capabilities for GSH-Au NCs, and thus selective determination of Cr(III) and Cr(VI) could be achieved at different pHs. Addition of EDTA was able to effectively eliminate the interferences from other metal ions, leading to a good selectivity for this method. Under optimized conditions, Cr(III) showed a linear range of 25-3800 μg L(-1) and a limit of detection (LOD) of 2.5 μg L(-1). The Cr(VI) ion demonstrated a linear range of 5-500 μg L(-1) and LOD of 0.5 μg L(-1). The run-to-run relative standard deviations (n=5) for Cr(III) and Cr(VI) were 3.9% and 2.8%, respectively. The recoveries of Cr(III) and Cr(VI) in environmental water samples were also satisfactory (76.3-116%). This method, with its simplicity, low cost, high selectivity and sensitivity, could be used as a promising tool for chromium analysis in environmental water samples.
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