scholarly journals Electrochemical Degradation of Metoprolol Using Graphite-PVC Composite as Anode: Elucidation and Characterization of New by-products Using LC-TOF/MS

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Fouad Fadhil Al-Qaim ◽  
Zainab Haider Mussa ◽  
Ali Yuzir ◽  
Kamyar Shameli
Keyword(s):  
Degradation Pathway ◽  
Strong Electrolyte ◽  
Electrochemical Degradation ◽  
Kinetic Rate Constant ◽  
Flight Mass Spectrometry ◽  
Nacl Concentration ◽  
Insuficiencia Cardiaca ◽  
Consumption Energy ◽  
Wastewater Samples ◽  
By Products

Abstract. Metoprolol (MTP) is one of pharmaceuticals used for treatment of heart failure and hypertension. It was frequently detected in wastewater samples either influent or effluent. The application of graphite-PVC composite as anode was investigated for the degradation of metoprolol in the presence of strong electrolyte such as sodium chloride (NaCl). The degradation rate was strongly influenced by initial concentrations of metoprolol, NaCl concentration and applied voltage. An initial concentration of 2 mg/L was eliminated more than 95% after 30 min under optimum conditions; 5000 mg/L NaCl and 5 V. The consumption energy of the electrochemical reaction was 0.665 Wh/mg for metoprolol after 30 min. The kinetic rate constant of metoprolol could be ranged between 0.0016 and 0.0801 min-1. The electrochemical degradation efficiency of metoprolol and its by-products has been achieved. The degradation of metoprolol produced four transformated products as investigated and elucidated using liquid chromatography-time of flight/mass spectrometry. The proposed degradation pathway of metoprolol was schemed on the base of the identified intermediates. Resumen. El metoprolol (MTP) es uno de los fármacos utilizados para el tratamiento de la insuficiencia cardíaca y la hipertensión. Se detecta frecuentemente en muestras de aguas residuales, ya sea de afluentes o efluentes. Se investigó la aplicación del compuesto de grafito-PVC como ánodo para la degradación del metoprolol en presencia de un electrolito fuerte como el cloruro de sodio (NaCl). La velocidad de degradación depende de las concentraciones iniciales de metoprolol, la concentración de NaCl y el voltaje aplicado. Una concentración inicial de 2 mg/L de MTP fue eliminada con más del 95% después de 30 minutos en condiciones óptimas; 5000 mg/L de NaCl y 5 V. La energía de consumo de la reacción electroquímica fue de 0,665 Wh/mg para el metoprolol después de 30 min. La constante cinética de degradación metoprolol oscila entre 0.0016 y 0.0801 min-1. Se logró la eficiente degradación electroquímica del metoprolol y sus subproductos, ya que se detectaron cuatro subproductos electrogenerados según los resultados de cromatografía líquida - tiempo de vuelo/espectrometría de masas. La vía de degradación propuesta del metoprolol se esquematizó sobre la base de los productos intermedios identificados.

scholarly journals Polyphenol Profiling of Chestnut Pericarp, Integument and Curing Water Extracts to Qualify These Food By-Products as a Source of Antioxidants

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2335
Author(s):  
Gabriella Pinto ◽  
Sabrina De Pascale ◽  
Maria Aponte ◽  
Andrea Scaloni ◽  
Francesco Addeo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Negative Impact ◽  
Tap Water ◽  
Time Of Flight ◽  
The Other ◽  
Curing Process ◽  
Flight Mass Spectrometry ◽  
Water Curing ◽  
The Impact ◽  
By Products

Plant polyphenols have beneficial antioxidant effects on human health; practices aimed at preserving their content in foods and/or reusing food by-products are encouraged. The impact of the traditional practice of the water curing procedure of chestnuts, which prevents insect/mould damage during storage, was studied to assess the release of polyphenols from the fruit. Metabolites extracted from pericarp and integument tissues or released in the medium from the water curing process were analyzed by matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electrospray-quadrupole-time of flight-mass spectrometry (ESI-qTOF-MS). This identified: (i) condensed and hydrolyzable tannins made of (epi)catechin (procyanidins) and acid ellagic units in pericarp tissues; (ii) polyphenols made of gallocatechin and catechin units condensed with gallate (prodelphinidins) in integument counterparts; (iii) metabolites resembling those reported above in the wastewater from the chestnut curing process. Comparative experiments were also performed on aqueous media recovered from fruits treated with processes involving: (i) tap water; (ii) tap water containing an antifungal Lb. pentosus strain; (iii) wastewater from a previous curing treatment. These analyses indicated that the former treatment determines a 6–7-fold higher release of polyphenols in the curing water with respect to the other ones. This event has a negative impact on the luster of treated fruits but qualifies the corresponding wastes as a source of antioxidants. Such a phenomenon does not occur in wastewater from the other curing processes, where the release of polyphenols was reduced, thus preserving the chestnut’s appearance. Polyphenol profiling measurements demonstrated that bacterial presence in water hampered the release of pericarp metabolites. This study provides a rationale to traditional processing practices on fruit appearance and qualifies the corresponding wastes as a source of bioactive compounds for other nutraceutical applications.

scholarly journals Investigation of Biotransformation Products of p-Methoxymethylamphetamine and Dihydromephedrone in Wastewater by High-Resolution Mass Spectrometry

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 66
Author(s):  
Juliet Kinyua ◽  
Aikaterini K. Psoma ◽  
Nikolaos I. Rousis ◽  
Maria-Christina Nika ◽  
Adrian Covaci ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Wastewater Treatment Plants ◽  
High Resolution Mass Spectrometry ◽  
Transformation Products ◽  
New Psychoactive Substances ◽  
Batch Reactors ◽  
Flight Mass Spectrometry ◽  
Detection And Identification ◽  
Wastewater Samples ◽  
Set Up

There is a paucity of information on biotransformation and stability of new psychoactive substances (NPS) in wastewater. Moreover, the fate of NPS and their transformation products (TPs) in wastewater treatment plants is not well understood. In this study, batch reactors seeded with activated sludge were set up to evaluate biotic, abiotic, and sorption losses of p-methoxymethylamphetamine (PMMA) and dihydromephedrone (DHM) and identify TPs formed during these processes. Detection and identification of all compounds was performed with target and suspect screening approaches using liquid chromatography quadrupole-time-of-flight mass spectrometry. Influent and effluent 24 h composite wastewater samples were collected from Athens from 2014 to 2020. High elimination rates were found for PMMA (80%) and DHM (97%) after a seven-day experiment and degradation appeared to be related to biological activity in the active bioreactor. Ten TPs were identified and the main reactions were O- and N-demethylation, oxidation, and hydroxylation. Some TPs were reported for the first time and some were confirmed by reference standards. Identification of some TPs was enhanced by the use of an in-house retention time prediction model. Mephedrone and some of its previously reported human metabolites were formed from DHM incubation. Retrospective analysis showed that PMMA was the most frequently detected compound.

scholarly journals Elucidation and Characterization of New Chlorinated By-Products after Electrochemical Degradation of Hydrochlorothiazide Using Graphite–Poly Vinyl Chloride Electrode

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 540
Author(s):  
Zainab Mussa ◽  
Fouad Al-Qaim ◽  
Ali Yuzir ◽  
Hirofumi Hara ◽  
Shamila Azman ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Treatment Process ◽  
Oxidation Process ◽  
Electrochemical Treatment ◽  
Electrochemical Process ◽  
Experimental Conditions ◽  
E Coli ◽  
Flight Mass Spectrometry ◽  
Negative Ionization ◽  
By Products

This paper describes an electrochemical treatment process of hydrochlorothiazide (HDZ) under different conditions such as initial concentration, sodium chloride and applied voltage. In this present study, HDZ was treated by electrochemical oxidation process using graphite-PVC composite electrode as anode and Platinum (Pt) as cathode. All results were analyzed using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS). It was found that at high applied voltages, and high amounts of NaCl, the electrochemical treatment process was more efficient. The removal% of HDZ was 92% at 5 V after 60 min. From the obtained results, the electrochemical oxidation process of HDZ followed pseudo first order with rate constant values ranged between 0.0009 and 0.0502 min−1, depending on the experimental conditions. Energy consumption was also considered in this study, it was ranged between 0.9058 and 5.56 Wh/mg using 0.5, 0.3 and 0.1 g NaCl within interval times of (10, 20, 30, 40, 50, 60, 70, and 80 min). Five chlorinated and one non-chlorinated by-products were formed and analyzed in negative ionization (NI) mode during the electrochemical process. Due to the strong oxidizing potential of the chlorine (Cl2) and hypochlorite ion (ClO−), HDZ and its by-products were removed after 140 min. Furthermore, a novel synthesis of chlorothiaizde as one of the new by-products was reported in this present study. Toxicity was impacted by the formation of the by-products, especially at 20 min. The inhibition percentage (I%) of E. coli bacteria was decreased to be the lowest value after 140 min.

Efficient removal of diuretic hydrochlorothiazide from water by electro-Fenton process using BDD anode: a kinetic and degradation pathway study

2019 ◽  
Vol 16 (8) ◽  
pp. 613 ◽  
Author(s):  
Hélène Monteil ◽  
Nihal Oturan ◽  
Yoan Péchaud ◽  
Mehmet A. Oturan
Keyword(s):  
Electrochemical Oxidation ◽  
Oxidation Reaction ◽  
Oxidation Process ◽  
Aqueous Media ◽  
Degradation Pathway ◽  
Constant Current ◽  
Gas Chromatography Mass Spectrometry ◽  
Aqueous Environment ◽  
Fenton Process ◽  
Kinetic Rate Constant

Environmental contextHydrochlorothiazide, a common diuretic pharmaceutical, occurs in environmental waters because current treatment technologies are unable to eliminate it from wastewater. To remove this environmentally hazardous chemical from water, we developed an advanced electrochemical oxidation process to efficiently degrade and mineralise the compound. Wider application of the process holds the promise of general, efficient destruction of pharmaceuticals in aqueous media. AbstractThe degradation and the mineralisation of the diuretic hydrochlorothiazide were studied by an advanced electrochemical oxidation process, ‘electro-Fenton’, which generates in situ hydroxyl radicals that are able to successfully oxidise or mineralise organic pollutants. In this study, a 0.1mM (29.8mgL−1) hydrochlorothiazide solution was completely oxidatively degraded in 15min under constant current electrolysis at 500 mA. The absolute kinetic rate constant of the oxidation reaction was also determined as (4.37±0.04)×109M−1s−1. The quasi-complete mineralisation of the solution was obtained with electrolysis for 6h under the same applied current. Several oxidation reaction intermediates were identified using gas chromatography-mass spectrometry (GC-MS). The formed carboxylic acids during the mineralisation process were also studied; oxamic, oxalic, acetic and maleic acids were identified and their concentrations were monitored throughout the electrolysis. The ions released during the treatment were also considered. Based on these data and the total organic carbon (TOC) removal results, a possible mineralisation pathway was proposed. These findings enable the conclusion that the electro-Fenton process is an efficient and environmentally-friendly method to eliminate the hazardous drug hydrochlorothiazide from an aqueous environment.

Effect of electrolyte on the current-carrying process in electrochemical machining

2007 ◽  
Vol 221 (11) ◽  
pp. 1415-1419 ◽  
Author(s):  
S K Mukherjee ◽  
S Kumar ◽  
P K Srivastava
Keyword(s):  
Narrow Range ◽  
Penetration Rate ◽  
Electrochemical Machining ◽  
Specific Conductance ◽  
Work Piece ◽  
Strong Electrolyte ◽  
Nacl Solution ◽  
Nacl Concentration ◽  
Iron Work

Role of electrolyte [NaCl] in current-carrying processes in electrochemical machining of iron work piece has been analysed in light of Onsagar equation of strong electrolyte. Over-voltage-calculated with respect to equilibrium gap and penetration rate, shows that only a narrow range of equilibrium gap and penetration rate are admissible. It has been found that the maximum specific conductance of NaCl solution is 0.0387 ohm-1 cm-1 at 1.5 M NaCl concentration. It appears that NaCl contribute only a fraction of current, on the other hand H+ and OH-produced by electrolysis of water play an important role in the current-carrying process.

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