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Zeng S, Qi P, Ai S, Sun X, Kang H, Bian D. Precise determination of the total nitrogen content in activated sludge by ultrasonic pre-treatment assisted wet method. ENVIRONMENTAL TECHNOLOGY 2023:1-11. [PMID: 38100606 DOI: 10.1080/09593330.2023.2285258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/11/2023] [Indexed: 12/17/2023]
Abstract
The study proposed a method for determining total nitrogen (TN) content in activated sludge by ultrasound pre-treatment assisted wet method. Based on the single-factor experiment, with the TN content as the response value, the response surface methodology was employed to examine the individual and interactive effects of three factors: the dilution multiple of the sludge mixture, ultrasonic time, and ultrasonic power. At the same time, the physico-chemical parameters and the digestion-oxidation parameters were optimised. The results indicated that the optimal parameters were as follows; sludge dilution multiple of 225 times, stirring rate of 400 r/min, ultrasonic time of 22 minutes, ultrasonic power of 720 W, and optimal added volume of potassium persulfate at 8 mL with a digestion time of 40 minutes. The relative standard deviation (RSD) for the parallel determination of TN in sludge samples using ultrasonic pre-treatment assisted wet method was ≤2.77%, with a spike recovery rate of 98.49-101.43%. The method, ultrasonic pre-treatment assisted wet method to determine TN concentration in activated sludge, was simpler to operate, more accurate.
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Affiliation(s)
- Shangjing Zeng
- Jilin Provincal Key Laboratory of Municipal Wastewater Treatment, School of Water Conservancy & Environment Engineering, Changchun Institute of Technology, Changchun, People's Republic of China
| | - Peng Qi
- Jilin Provincal Key Laboratory of Municipal Wastewater Treatment, School of Water Conservancy & Environment Engineering, Changchun Institute of Technology, Changchun, People's Republic of China
| | - Shengshu Ai
- Jilin Provincal Key Laboratory of Municipal Wastewater Treatment, School of Water Conservancy & Environment Engineering, Changchun Institute of Technology, Changchun, People's Republic of China
| | - Xuejian Sun
- Jilin Provincal Key Laboratory of Municipal Wastewater Treatment, School of Water Conservancy & Environment Engineering, Changchun Institute of Technology, Changchun, People's Republic of China
- School of Environment, Northeast Normal University, Changchun, People's Republic of China
| | - Hua Kang
- Jilin Provincal Key Laboratory of Municipal Wastewater Treatment, School of Water Conservancy & Environment Engineering, Changchun Institute of Technology, Changchun, People's Republic of China
| | - Dejun Bian
- Jilin Provincal Key Laboratory of Municipal Wastewater Treatment, School of Water Conservancy & Environment Engineering, Changchun Institute of Technology, Changchun, People's Republic of China
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2
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Forrest T, Cherubini T, Jeanneret S, Zdrachek E, Damala P, Bakker E. A submersible probe with in-line calibration and a symmetrical reference element for continuous direct nitrate concentration measurements. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:519-530. [PMID: 36655724 DOI: 10.1039/d2em00341d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Current methods to monitor nitrate levels in freshwater systems are outdated because they require expensive equipment and manpower. Punctual sampling on the field or at a fixed measuring station is still the accepted monitoring procedure and fails to provide real-time estimation of nitrate levels. Continuous information is of crucial importance to evaluate the health of natural aquatic systems, which can strongly suffer from a nitrogen imbalance. We present here a nitrate-selective potentiometric probe to measure the analyte continuously without requiring maintenance or high-power consumption. Owing to a simple design where the sensors are located directly in contact with the sample, the need for constant pump usage is eliminated, requiring just 0.7 mW power per day instead of 184 mW per day and per pump. It is estimated that with this power consumption, the setup can easily run for more than 97 h on four simple Li-ion batteries. A simple in-line one-point calibration step was implemented to allow for drift correction. At the same time, a symmetrical design was used involving a second nitrate probe as a reference electrode placed in the calibrant compartment. This, combined with an in situ calibration step, allows one to quantify nitrate ion concentrations directly, instead of yielding activities. The dependence on ion activity was removed by using the analysed sample spiked with nitrate as the calibrant. This results in essentially the same activity coefficients and additionally reduces junction potentials to a fraction of a millivolt. In addition, a symmetrical reference element served to compensate for fluctuations caused by environmental factors (temperature, convection, etc.) to achieve improved stability and signal reproducibility compared to a traditional Ag/AgCl based reference electrode. The final prototype was deployed in the Arve River in Geneva for 75 h without requiring any intervention. The nitrate levels measured using the symmetrical reference element over this period were estimated at 44.0 ± 3.5 M and agreed well with the values obtained with ion chromatography (38.2 ± 2.1 μM) used as the reference method. Thanks to a modular sensing head the potentiometric sensors can be easily exchanged, making it possible to quantify other types of analytes and leading the way to a new monitoring strategy.
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Affiliation(s)
- Tara Forrest
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
| | - Thomas Cherubini
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
| | - Stéphane Jeanneret
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
| | - Elena Zdrachek
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
| | - Polyxeni Damala
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
| | - Eric Bakker
- Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
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Geng J, Yang C, Lan L, Li Y, Han J, Zhou C. Online rapid total nitrogen detection method based on UV spectrum and spatial interval permutation combination population analysis. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 274:121009. [PMID: 35248853 DOI: 10.1016/j.saa.2022.121009] [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: 09/06/2021] [Revised: 01/17/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Rapidly and accurately detect the total nitrogen (TN) concentration is enormously important for surface water protection considering the critical role it plays in reflecting the eutrophication of surface water. However, traditional TN detection methods have to experience a tedious oxygen digestion process, which tremendously limits the detection speed of TN. To solve this problem, we propose a novel online rapid TN detection method. The transformations of nitrogenous substances during the oxidative digestion process are observed by using ultraviolet (UV) spectroscopy and the concentration of TN can be predicted by only using the variation of spectrum in the early oxygen digestion process. To select the most informative variables hidden in the collected three-dimension spectrum, a new wavelength selection algorithm called spatial interval permutation combination population analysis (siPCPA) is proposed, which considers the spatial-temporal relationships among each variable in the spectrum. By using the real surface water samples collected from Houhu Lake, Changsha, China, the effectiveness of our proposed new detection and selection methods are verified and compared with other state-of-the-art methods. As a result, the practical application experiment shows that our methods can determine the concentration of TN in 5 min with a relative error of less than 5%.
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Affiliation(s)
- Jingxuan Geng
- School of Automation, Central South University, 410083 Changsha, China
| | - Chunhua Yang
- School of Automation, Central South University, 410083 Changsha, China
| | - Lijuan Lan
- School of Automation, Central South University, 410083 Changsha, China.
| | - Yonggang Li
- School of Automation, Central South University, 410083 Changsha, China
| | - Jie Han
- School of Automation, Central South University, 410083 Changsha, China
| | - Can Zhou
- School of Automation, Central South University, 410083 Changsha, China
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4
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Saez J, Catalan-Carrio R, Owens RM, Basabe-Desmonts L, Benito-Lopez F. Microfluidics and materials for smart water monitoring: A review. Anal Chim Acta 2021; 1186:338392. [PMID: 34756264 DOI: 10.1016/j.aca.2021.338392] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/02/2021] [Accepted: 03/02/2021] [Indexed: 01/03/2023]
Abstract
Water quality monitoring of drinking, waste, fresh and seawaters is of great importance to ensure safety and wellbeing for humans, fauna and flora. Researchers are developing robust water monitoring microfluidic devices but, the delivery of a cost-effective, commercially available platform has not yet been achieved. Conventional water monitoring is mainly based on laboratory instruments or sophisticated and expensive handheld probes for on-site analysis, both requiring trained personnel and being time-consuming. As an alternative, microfluidics has emerged as a powerful tool with the capacity to replace conventional analytical systems. Nevertheless, microfluidic devices largely use conventional pumps and valves for operation and electronics for sensing, that increment the dimensions and cost of the final platforms, reducing their commercialization perspectives. In this review, we critically analyze the characteristics of conventional microfluidic devices for water monitoring, focusing on different water sources (drinking, waste, fresh and seawaters), and their application in commercial products. Moreover, we introduce the revolutionary concept of using functional materials such as hydrogels, poly(ionic liquid) hydrogels and ionogels as alternatives to conventional fluidic handling and sensing tools, for water monitoring in microfluidic devices.
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Affiliation(s)
- Janire Saez
- Microfluidics Cluster UPV/EHU, Analytical Microsystems & Materials for Lab-on-a-Chip (AMMa-LOAC), Group, Analytical Chemistry, University of the Basque Country UPV/EHU, Spain; Bioelectronic Systems Technology Group, Department of Chemical Engineering and Biotechnology, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK.
| | - Raquel Catalan-Carrio
- Microfluidics Cluster UPV/EHU, Analytical Microsystems & Materials for Lab-on-a-Chip (AMMa-LOAC), Group, Analytical Chemistry, University of the Basque Country UPV/EHU, Spain; Microfluidics Cluster UPV/EHU, BIOMICs Microfluidics Group, Lascaray Research Center, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
| | - Róisín M Owens
- Bioelectronic Systems Technology Group, Department of Chemical Engineering and Biotechnology, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Lourdes Basabe-Desmonts
- Microfluidics Cluster UPV/EHU, BIOMICs Microfluidics Group, Lascaray Research Center, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain; Basque Foundation for Science, IKERBASQUE, Spain; Bioaraba Health Research Institute, Microfluidics Cluster UPV/EHU, Vitoria-Gasteiz, Spain; BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940, Leioa, Spain.
| | - Fernando Benito-Lopez
- Microfluidics Cluster UPV/EHU, Analytical Microsystems & Materials for Lab-on-a-Chip (AMMa-LOAC), Group, Analytical Chemistry, University of the Basque Country UPV/EHU, Spain; Bioaraba Health Research Institute, Microfluidics Cluster UPV/EHU, Vitoria-Gasteiz, Spain; BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940, Leioa, Spain.
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5
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Lin K, Xu J, Guo H, Huo Y, Zhang Y. Flow injection analysis method for determination of total dissolved nitrogen in natural waters using on-line ultraviolet digestion and vanadium chloride reduction. Microchem J 2021. [DOI: 10.1016/j.microc.2021.105993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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Measurement of Total Nitrogen Concentration in Surface Water Using Hyperspectral Band Observation Method. WATER 2020. [DOI: 10.3390/w12071842] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nitrogen overload is one of the main reasons for the deterioration of surface water quality. Hence, monitoring nitrogen loadings is vital in maintaining good surface water quality. Increasingly, the use of spectral reflectance to monitor nitrogen concentration in water has shown potentials, but it poses some problems. Therefore, it is necessary to explore new methods of quantitative monitoring of nitrogen concentration in surface water. In this paper, hyperspectral data from surface water in the Ebinur Lake watershed are used to select sensitive bands using spectral transformation, the spectral index, and a coupling of these two methods. The particle swarm optimization support vector machine (PSO-SVM) model, constructed on the basis of sensitive bands, is used quantitatively to estimate the total nitrogen concentration in surface water and subsequently to verify its accuracy. The results show that the bands near 680, 850, and 940 nm can be used as sensitive bands for estimation of the total nitrogen concentration of surface water in arid regions. Compared with the best estimation models constructed by sensitive bands selected using the spectral transformation or the spectral index alone, the best model based on the coupling of these two measures is more accurate (R2 = 0.604, Root Mean Square Error (RMSE) = 1.61 mg/L, Residual Prediction Deviation (RPD) = 2.002). This coupling method leads to a robust, accurate, and strong predictability model, and can contribute to improved quantitative estimation of water quality indexes of rivers in arid regions.
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7
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Investigations on Ozone-Based and UV/US-Assisted Synergistic Digestion Methods for the Determination of Total Dissolved Nitrogen in Waters. Processes (Basel) 2020. [DOI: 10.3390/pr8040490] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Over the past two decades, the alkaline persulfate oxidation (PO) with thermal and/or ultraviolet (UV) assisted digestion method has been widely used for digestion of nitrogen containing compounds (N-compounds) in water quality routine analysis in laboratory or on-line analysis, due to its simple principle, high conversion rate, high percent recovery, low-cost. However, this digestion method still has some inevitable problems such as complex operations, high contamination potential, batch N blanks, higher reaction temperature (120–124 °C) and time-consuming (30–60 min). In this study, ozone (O3) was selected as the oxidant for digestion of N-compounds through analysis and comparison firstly. Secondly, we proposed and compared the UV and/or ultrasound (US) combined with ozone (UV/O3, US/O3 and UV/US/O3) synergistic digestion methods based on O3 with sole O3 oxidation method on digestion efficiency (digestion time and conversion rate) of standard N-compounds. Simultaneously, the influence of reaction temperature, pH of water sample, concentration of O3 and mass flow rate, UV intensity, US frequency and power on digestion efficiency were investigated, and then the optimum parameters for digestion system were obtained. Experimental results indicated that UV radiation can effectively induce and promote the decomposition and photolysis of O3 in water to generate hydroxyl radicals (•OH), while US can promote the diffusion and dissolution of O3 in water and intensify the gas-liquid mass transfer process for the reaction system. Meanwhile, results showed that the UV/US/O3 synergistic digestion method had the best digestion efficiency under the optimum conditions: water sample volume, 10 mL; pH of water sample, 11; O3 mass flow rate, 3200 mg/h; reaction temperature, 30 °C; digestion time, 25 min; UV lamp power, 18 W; distance between UV lamp and reactor, 2 cm; US frequency, 20 kHz; US power, 75 W. The conversion rate (CR) of synthetic wastewater samples varied from 99.6% to 101.4% for total dissolved nitrogen (TDN) in the range of 1.0~4.0 mg/L. The UV/US/O3 synergistic digestion method would be an effective and potential alternative for digestion of N-compounds in water quality routine analysis in laboratory or on-line analysis.
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8
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Lin B, Xu J, Lin K, Li M, Lu M. Low-Cost Automatic Sensor for in Situ Colorimetric Detection of Phosphate and Nitrite in Agricultural Water. ACS Sens 2018; 3:2541-2549. [PMID: 30406654 DOI: 10.1021/acssensors.8b00781] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study proposed a low-cost sensor for in situ automatic monitoring of phosphate and nitrite in agricultural water environments, involving a series of "Fish-Bite" reservoirs, multiple reagent capsules, and a colorimetric sensor. The Fish-Bite reservoir is an alternative to the pumps, valves, and filters that are widely used for water sample collection and also offers a closed cell for chromogenic reactions afterward. Up to two capsules can be embedded in each reservoir to support chromogenic reactions that use two different reagents in sequence. From the results of calibration tests in the laboratory, the limit of detection was found to be approximately 0.01 mg/L for both phosphate and nitrite, with a linear range of 0.01-1.00 mg/L for phosphate and 0.01-0.20 mg/L for nitrite. Furthermore, an in situ experiment was successfully carried out in an irrigation canal beside farmland to demonstrate the practicability and robustness of the device. The averaged concentrations of phosphate and nitrite were 0.0113 mg/L and 0.0383 mg/L, respectively. The relative deviations were 20.2% and 11.7%, respectively, referred to results obtained by using the standard spectrophotometric methods. With the advantages of being robust, fast, and low cost, this in situ device is promising for the formation of agricultural sensor networks.
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Affiliation(s)
- Beichen Lin
- Pen-Tung Sah Institute of Micro-Nano Science & Technology, Xiamen University, Xiamen 361005, China
| | - Jin Xu
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Kunning Lin
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Mingpo Li
- Pen-Tung Sah Institute of Micro-Nano Science & Technology, Xiamen University, Xiamen 361005, China
| | - Miao Lu
- Pen-Tung Sah Institute of Micro-Nano Science & Technology, Xiamen University, Xiamen 361005, China
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9
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Singh P, Singh MK, Beg YR, Nishad GR. A review on spectroscopic methods for determination of nitrite and nitrate in environmental samples. Talanta 2018; 191:364-381. [PMID: 30262072 DOI: 10.1016/j.talanta.2018.08.028] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 12/20/2022]
Abstract
Nitrate is an important pollutant found in environmental samples. Nitrate and nitrite pose various environmental as well as health hazards. Different methods of determining nitrate in various environmental samples developed during previous years include spectrophotometric, chemiluminescence, electrochemical detection, chromatographic, capillary electrophoretic, spectrofluorimetric methods. Out of these, methods based on spectroscopic detection of nitrate have been discussed in this review article due to their easy availability, high sensitivity, low detection limit, economical and facile nature. Methods based on spectrophotometry, Raman Spectroscopy, IR and FTIR Spectroscopy, atomic absorption spectroscopy (AAS), fluorescence spectroscopy, chemiluminescence, mass spectroscopy, molecular emission cavity analysis (MECA), electron paramagnetic resonance spectrometry (EPR) and nuclear magnetic resonance spectroscopy (NMR) have been reviewed. The basic principle, detection limits, detection range, RSD%, sample throughput/h, advantages and disadvantages have been discussed.
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Affiliation(s)
- Priyanka Singh
- Department of Chemistry, Govt. Digvijay PG Autonomous College, Rajnandgaon 491441, Chhattisgarh, India.
| | | | - Younus Raza Beg
- Department of Chemistry, Govt. Digvijay PG Autonomous College, Rajnandgaon 491441, Chhattisgarh, India
| | - Gokul Ram Nishad
- Department of Chemistry, Govt. Digvijay PG Autonomous College, Rajnandgaon 491441, Chhattisgarh, India
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10
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Shih YJ, Huang YH, Huang C. In-situ electrochemical formation of nickel oxyhydroxide (NiOOH) on metallic nickel foam electrode for the direct oxidation of ammonia in aqueous solution. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.05.169] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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11
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Pagliano E, Campanella B, Shi L, Thibeault MP, Onor M, Crum S, Melanson JE, Mester Z. Determination of total dissolved nitrogen in seawater by isotope dilution gas chromatography mass spectrometry following digestion with persulfate and derivatization with aqueous triethyloxonium. J Chromatogr A 2018; 1569:193-199. [PMID: 30076005 DOI: 10.1016/j.chroma.2018.07.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/13/2018] [Accepted: 07/17/2018] [Indexed: 10/28/2022]
Abstract
In this study, we propose a novel approach for the determination of total dissolved nitrogen (TDN) in seawater combining high-precision isotope dilution GC-MS with persulfate digestion. A 2 mL sample aliquot was digested with an alkaline solution of persulfate to convert nitrogen containing compounds to nitrate. Digested samples were spiked with 15NO3- internal standard and treated with aqueous triethyloxonium to convert the analyte into volatile EtONO2. This derivative was readily separated from the matrix under gaseous form and could be sampled from the headspace before GC-MS analysis. The resulting chromatograms showed a stable flat baseline with EtONO2 as the only eluting peak (retention time 2.75 min on a DB 5.625 column). Such an approach provides specificity and obviates the shortcomings of current detection methods employed to analyze seawater samples after digestion with persulfate. In negative chemical ionization mode, the method reached a detection limit of 0.5 μmol/kg TDN (7 ng/g N) and could be applied to quantify seawater samples with 1-25 μmol/kg TDN. On the upper end of the range, quantitation could be repeated within 1%, whereas on a 6 μmol/kg TDN sample repeatability was 2.3% on eight measurements. The method was employed in two proficiency testing exercises providing results in agreement with consensus values. We investigated the impact of reagent blank and we implemented a blank-matching optimal design to account for such contribution. Finally, we performed a study on the yield of persulfate oxidation for organic and inorganic nitrogen compounds typically present in seawater. Whilst nitrite and ammonium are fully converted to nitrate, more complex organic molecules showed recoveries varying from 70% to 100%.
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Affiliation(s)
- Enea Pagliano
- National Research Council of Canada, 1200 Montreal Road, K1A 0R6 Ottawa, Ontario, Canada.
| | - Beatrice Campanella
- Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica dei Composti Organometallici, UOS di Pisa, Via Moruzzi 1, 56124 Pisa, Italy
| | - Lisa Shi
- National Research Council of Canada, 1200 Montreal Road, K1A 0R6 Ottawa, Ontario, Canada
| | - Marie-Pier Thibeault
- National Research Council of Canada, 1200 Montreal Road, K1A 0R6 Ottawa, Ontario, Canada
| | - Massimo Onor
- Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica dei Composti Organometallici, UOS di Pisa, Via Moruzzi 1, 56124 Pisa, Italy
| | - Steven Crum
- QUASIMEME, NL-6700 EC Wageningen, Bornsesteeg 10, 6721 NG Bennekom, The Netherlands
| | - Jeremy E Melanson
- National Research Council of Canada, 1200 Montreal Road, K1A 0R6 Ottawa, Ontario, Canada
| | - Zoltán Mester
- National Research Council of Canada, 1200 Montreal Road, K1A 0R6 Ottawa, Ontario, Canada
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12
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Simultaneous determination of total dissolved nitrogen and total dissolved phosphorus in natural waters with an on-line UV and thermal digestion. Talanta 2018; 185:419-426. [PMID: 29759221 DOI: 10.1016/j.talanta.2018.03.085] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/12/2018] [Accepted: 03/25/2018] [Indexed: 11/22/2022]
Abstract
A flow injection method combined with an on-line UV and thermal digestion for simultaneous determination of total dissolved nitrogen (TDN) and total dissolved phosphorus (TDP) in natural waters was established in this study. A novel flow manifold made the proposed system compact and automatic. The conversion rates of various nitrogen and phosphorus compounds to their nitrate and phosphate forms with different digestion models and different concentrations were well investigated using the flow injection technique. The reagent concentrations for colorimetric analysis were optimized based on a univariate experimental design. The detection limits were 0.8 μmol L-1 and 0.2 μmol L-1, and linear analytical ranges were up to 300 μmol L-1 and 25 μmol L-1 for TDN and TDP, respectively. The sample throughput was ~ 5 h-1. The recovery of spiked natural water samples varied from 86.8% to 102.6% for TDN and 88.0% to 102.0% for TDP. The present approach was successfully applied for the determination of TDN and TDP in natural water samples and was found to have good agreement with reference methods. The outcomes of present study indicated that the proposed method is suitable for routine analysis as well as for potential on-line monitoring.
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13
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Electrocatalytic ammonia oxidation over a nickel foam electrode: Role of Ni(OH)2(s)-NiOOH(s) nanocatalysts. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.01.045] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Shih YJ, Huang YH, Huang C. Oxidation of ammonia in dilute aqueous solutions over graphite-supported α- and β-lead dioxide electrodes (PbO2@G). Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.10.060] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Duffy G, Regan F. Recent developments in sensing methods for eutrophying nutrients with a focus on automation for environmental applications. Analyst 2017; 142:4355-4372. [DOI: 10.1039/c7an00840f] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A comprehensive review focusing on eutrophying nutrient monitoring using autonomous sensors, including novel analysis methods, standard analysis methods and state-of-the-art sensor technology.
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Affiliation(s)
- G. Duffy
- Water Institute
- School of Chemical Sciences
- Dublin City University
- Dublin
- Ireland
| | - F. Regan
- Water Institute
- School of Chemical Sciences
- Dublin City University
- Dublin
- Ireland
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16
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Toral MI, Nacaratte F, Nova F. Determination of Etonogestrel and Ethinyl Estradiol from an Intrauterine Contraceptive Ring by Extraction and Derivative Spectrophotometry. ANAL LETT 2015. [DOI: 10.1080/00032719.2014.968930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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17
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Brandao GC, Matos GD, Pereira RN, Ferreira SL. Development of a simple method for the determination of nitrite and nitrate in groundwater by high-resolution continuum source electrothermal molecular absorption spectrometry. Anal Chim Acta 2014; 806:101-6. [DOI: 10.1016/j.aca.2013.11.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Revised: 11/09/2013] [Accepted: 11/14/2013] [Indexed: 12/27/2022]
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18
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Flow injection analysis as a tool for enhancing oceanographic nutrient measurements—A review. Anal Chim Acta 2013; 803:15-40. [DOI: 10.1016/j.aca.2013.06.015] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 06/13/2013] [Accepted: 06/15/2013] [Indexed: 11/21/2022]
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19
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Application of the calibration surfaces method in quantitative analysis of water — ethanol — methanol mixture. OPEN CHEM 2013. [DOI: 10.2478/s11532-013-0252-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe simple and quick calibration surfaces method has been applied to the quantitative analysis of water — ethanol — methanol mixtures. The refractive index, viscosity, boiling point, density, and position of the absorption band of the solvatochromic dye and the absorbance of the band corresponding to a particular wavelength were used as measured magnitudes which are functionally related to the quantitative composition of the mixture. The 3rd order surface equation was fitted to the experimental data via the multidimensional regression method. Various pairs of macroscopic features were tested to obtain the best results. To find the solution, the set of three equations were calculated, in which two equations were the mathematical description of particular macroscopic features; the third one resulted from the definition of mass fraction. The detection and determination limits as well as the error of the method were determined which proved that the refractive index and the density were the most adequate pair of macroscopic features.
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