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Soltani-Shahrivar M, Afkhami A, Madrakian T, Jalal NR. Sensitive and selective impedimetric determination of TNT using RSM-CCD optimization. Talanta 2023; 257:124381. [PMID: 36801757 DOI: 10.1016/j.talanta.2023.124381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/05/2023] [Accepted: 02/15/2023] [Indexed: 02/18/2023]
Abstract
Detection of trace amounts of 2,4,6-Trinitrotoluene as a widely used explosive in the military and industrial sectors is of vital importance due to security and environmental concerns. The sensitive and selective measurement characteristics of the compound still is considered a challenge for analytical chemists. Unlike conventional optical and electrochemical methods, the electrochemical impedance spectroscopy technique (EIS), has a very high sensitivity, but it faces a significant challenge in that it requires complex and expensive steps to modify the electrode surface with selective agents. We reported the design and construction of an inexpensive, simple, sensitive, and selective impedimetric electrochemical TNT sensor based on the formation of a Meisenheimer complex between magnetic multiwalled carbon nanotubes modified with aminopropyl triethoxysilane (MMWCNTs @ APTES) and TNT. The formation of the mentioned charge transfer complex at the electrode-solution interface blocks the electrode surface and disrupts the charge transfer in [(Fe (CN) 6)] 3-/4- redox probe system. Charge transfer resistance changes (ΔRCT) were used as an analytical response that corresponded to TNT concentration. To investigate the influence of effective parameters on the electrode response, such as pH, contact time, and modifier percentage, the response surface methodology based on central composite design (RSM-CCD) was used. The calibration curve was achieved in the range of 1-500 nM with a detection limit of 0.15 nM under optimal conditions, which included pH of 8.29, contact time of 479 s, and modifier percentage of 12.38% (w/w). The selectivity of the constructed electrode towards several nitroaromatic species was investigated, and no significant interference was found. Finally, the proposed sensor was able to successfully measure TNT in various water samples with satisfactory recovery percentages.
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Affiliation(s)
| | - Abbas Afkhami
- Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran; D-8 International University, Hamedan, Iran.
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Pal S, Chattopadhyay A. Simultaneous Sensing of H 2 O, D 2 O and HOD through Peroxo Vibrations. Chemphyschem 2022; 24:e202200684. [PMID: 36541063 DOI: 10.1002/cphc.202200684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
Detection of HOD simultaneously in the presence of a mixture of H2 O and D2 O is still an experimental challenge. Till date, there is no literature report of simultaneous detection of H2 O, D2 O and HOD based on vibrational spectra. Herein we report simultaneous quantitative detection of H2 O, D2 O and HOD in the same reaction mixture with the help of bridged polynuclear peroxo complex in absence and presence of Au nanoparticles on the basis of a peroxide vibrational mode in resonance Raman and surface enhanced resonance Raman spectrum. We synthesize bridged polynuclear peroxo complex in different solvent mixture of H2 O and D2 O. Due to the formation of different nature of hydrogen bonding between peroxide and solvent molecules (H2 O, D2 O and HOD), vibrational frequency of peroxo bond is significantly affected. Mixtures of different H2 O and D2 O concentrations produce different HOD concentrations and that lead to different intensities of peaks positioned at 897, 823 and 867 cm-1 indicating H2 O, D2 O and HOD, respectively. The lowest detection limits (LODs) were 0.028 mole fraction of D2 O in H2 O and 0.046 mole faction of H2 O in D2 O. In addition, for the first time the results revealed that the cis-peroxide forms two hydrogen bonds with solvent molecules.
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Affiliation(s)
- Srimanta Pal
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Arun Chattopadhyay
- Department of Chemistry, Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
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Fan Y, Wang X, Funk T, Rashid I, Herman B, Bompoti N, Mahmud MS, Chrysochoou M, Yang M, Vadas TM, Lei Y, Li B. A Critical Review for Real-Time Continuous Soil Monitoring: Advantages, Challenges, and Perspectives. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:13546-13564. [PMID: 36121207 DOI: 10.1021/acs.est.2c03562] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Most soil quality measurements have been limited to laboratory-based methods that suffer from time delay, high cost, intensive labor requirement, discrete data collection, and tedious sample pretreatment. Real-time continuous soil monitoring (RTCSM) possesses a great potential to revolutionize field measurements by providing first-hand information for continuously tracking variations of heterogeneous soil parameters and diverse pollutants in a timely manner and thus enable constant updates essential for system control and decision-making. Through a systematic literature search and comprehensive analysis of state-of-the-art RTCSM technologies, extensive discussion of their vital hurdles, and sharing of our future perspectives, this critical review bridges the knowledge gap of spatiotemporal uninterrupted soil monitoring and soil management execution. First, the barriers for reliable RTCSM data acquisition are elucidated by examining typical soil monitoring techniques (e.g., electrochemical and spectroscopic sensors). Next, the prevailing challenges of the RTCSM sensor network, data transmission, data processing, and personalized data management are comprehensively discussed. Furthermore, this review explores RTCSM data application for updating diverse strategies including high-fidelity soil process models, control methodologies, digital soil mapping, soil degradation, food security, and climate change mitigation. Finally, the significance of RTCSM implementation in agricultural and environmental fields is underscored through illuminating future directions and perspectives in this systematic review.
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Affiliation(s)
- Yingzheng Fan
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Xingyu Wang
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Thomas Funk
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Ishrat Rashid
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Brianna Herman
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Nefeli Bompoti
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Md Shaad Mahmud
- Department of Electrical and Computer Engineering, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Maria Chrysochoou
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Meijian Yang
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Timothy M Vadas
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yu Lei
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Baikun Li
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
- Center for Environmental Science and Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
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Xiao D, Yan Z, Li J, Fu Y, Li Z, Li B. Coal Identification Based on Reflection Spectroscopy and Deep Learning: Paving the Way for Efficient Coal Combustion and Pyrolysis. ACS OMEGA 2022; 7:23919-23928. [PMID: 35847264 PMCID: PMC9280928 DOI: 10.1021/acsomega.2c02665] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Coal plays an indispensable role in the world's energy structure. Coal converts chemical energy into energy such as electricity, heat, and internal energy through combustion. To realize the energy conversion of coal more efficiently, coal needs to be identified during the stages of mining, combustion, and pyrolysis. On this basis, different categories of coal are used according to industrial needs, or different pyrolysis processes are selected according to the category of coal. This paper proposes an approach combining deep learning with reflection spectroscopy for rapid coal identification in mining, combustion, and pyrolysis scenarios. First, spectral data of different coal samples were collected in the field and these spectral data were preprocessed. Then, an identification model combining a multiscale convolutional neural network (CNN) and an extreme learning machine (ELM), named RS_PSOTELM, is proposed. The effective features in the spectral data are extracted by the CNN, and the feature classification is realized utilizing the ELM. To enhance the identification performance of the model, we utilize a particle swarm optimization algorithm to optimize the parameters of the ELM. Experimental results show that RS_PSOTELM achieves 98.3% accuracy on the coal identification task and is able to identify coal quickly and accurately, providing a low-cost, efficient, and reliable approach for coal identification during the mining and application phases, as well as paving the way for efficient combustion and pyrolysis of coal.
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Affiliation(s)
- Dong Xiao
- School
of Information Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Zelin Yan
- School
of Information Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Jian Li
- Technical
Service Parlor, Unit 31434 of the Chinese
People’s Liberation Army, Shenyang 110000, China
| | - Yanhua Fu
- School
of JangHo Architecture, Northeastern University, Shenyang 110819, China
| | - Zhenni Li
- School
of Information Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Boyan Li
- School
of Information Science and Engineering, Northeastern University, Shenyang 110819, China
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