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Journal of AOAC International Mar 2017An analytical method for determining the presence and levels of residual active ingredients found in neutralized suspensions of phenolic and quaternary ammonium...
An analytical method for determining the presence and levels of residual active ingredients found in neutralized suspensions of phenolic and quaternary ammonium salt-based antimicrobial products was developed using solid-phase extraction in combination with LC-tandem MS. A single-laboratory validation of the method was performed at three concentration levels for the quaternary ammonium compounds (also referred to as benzalkonium chlorides or BACs) and the phenols in the presence of letheen broth neutralizer at 2.5 and 2.75 μg/mL, respectively, as well as at dilutions of 1:10 and 1:100 in those concentrations. The method's lowest LODs were 0.005 μg/g for BACs and 0.006 μg/g for phenols. The average recovery of the fortified samples for both active ingredients ranged between 80 and 124%, and RSDs were generally <20%. In a related study, the effectiveness of letheen broth with and without sodium thiosulfate was evaluated as a neutralizer for sodium hypochlorite. The results showed that letheen broth without sodium thiosulfate neutralizes chlorine concentrations up to 60 ppm, and that 200 μg sodium thiosulfate are required to neutralize a 72 ppm concentrated chlorine solution in letheen broth.
Topics: Anti-Infective Agents; Benzalkonium Compounds; Biphenyl Compounds; Chromatography, Ion Exchange; Culture Media; Dichlorophen; Lipids; Phenols; Sodium Hypochlorite; Tandem Mass Spectrometry; Thiosulfates
PubMed: 28118571
DOI: 10.5740/jaoacint.16-0244 -
Environmental Pollution (Barking, Essex... Sep 2019Increasing attention has been attracted in developing new technologies to remove chlorofene (CF) and dichlorofene (DCF), which were active agents in antimicrobials for...
Increasing attention has been attracted in developing new technologies to remove chlorofene (CF) and dichlorofene (DCF), which were active agents in antimicrobials for general cleaning and disinfecting. This study investigated the significant influences of bicarbonate (HCO) on the degradation of CF and DCF in the Cu(II)-mediated Fenton-like system Cu/HO. Our results indicate that HCO may play a dual role to act 1) as a ligand to stabilize Cu(II), forming soluble [Cu(HCO)(S)] species to catalyze HO producing hydroxyl radical (OH) and superoxide ion (O) and 2) as a OH scavenger. Furthermore, the reaction kinetics, mechanisms, and intermediates of CF and DCF were assessed. The apparent rate constants of CF and DCF were enhanced by a factor of 8.5 and 5.5, respectively, in the presence of HCO at the optimized concentration of 4 mM. Based on the intermediate identification and frontier electron densities (FEDs) calculations, the associated reaction pathways were tentatively proposed, including C-C scission, single or multiple hydroxylation, and coupling reaction. In addition, significant reduction in the aquatic toxicity of CF and DCF was observed after treatment with Cu/HO-HCO system, evaluated by Ecological Structure Activity Relationships (ECOSAR) program. These findings provide new insights into Cu(II)-mediated reactions to better understand the environmental fate of organic contaminants in carbonate-rich waters.
Topics: Anti-Bacterial Agents; Bicarbonates; Carbonates; Chlorophenols; Copper; Dichlorophen; Disinfectants; Environmental Restoration and Remediation; Hydrocarbons, Halogenated; Hydrogen Peroxide; Hydroxyl Radical; Iron; Kinetics; Oxidation-Reduction; Phenol
PubMed: 31227352
DOI: 10.1016/j.envpol.2019.05.148 -
Chemosphere Jan 2017Dichlorophene; a halogenated phenolic compound with wide applications as a fungicide, bactericide and antiprotozoan. Dichlorophene spray also has therapeutic use in the...
Dichlorophene; a halogenated phenolic compound with wide applications as a fungicide, bactericide and antiprotozoan. Dichlorophene spray also has therapeutic use in the disease digital dermatitis. In guinea pigs, a few studies obtained mixed results in dicholorophene sensitization tests. In consideration of the fact, that the mechanism of its genotoxicity has not been adequately elucidated lead to present study assessing the acute in vivo toxicological impact in Rattus norvegicus. A systematic research has been made encompassing the use of molecular and flow cytometric approaches. The study was designed on blood cells for comet assay which revealed dichlorophene induced DNA damage in all exposures understandable in time dependent manner. The feasibility of this assay was also established as an effective, fast and accurate method with a great potential in biomonitoring. Contemporary molecular techniques were further engaged using leukocytes for the cell apoptosis/cycle and mitochondrial membrane potential employing propidium iodide staining and rhodamine 123 respectively. The effect on cell cycle phases and mitochondrial membrane permeability was analyzed through flow cytometry. These indicators exposed that dichlorophene decreased the mitochondrial membrane potential, altered the cell cycle and confirmed the DNA damage leading to apoptosis of the cells of the immune system accountable for immunotoxic effects of dichlorophene on rat leukocytes.
Topics: Animals; Apoptosis; Cell Cycle; Cells, Cultured; Comet Assay; DNA Damage; Dichlorophen; Environmental Pollutants; Flow Cytometry; Humans; Leukocytes, Mononuclear; Lymphocytes; Membrane Potential, Mitochondrial; Propidium; Rats, Wistar; Toxicogenetics
PubMed: 27764745
DOI: 10.1016/j.chemosphere.2016.08.131 -
Environmental Science & Technology Nov 2018Potassium ferrate [Fe(VI)] is a promising oxidant widely used in water treatment for the elimination of organic pollutants. In this work, the reaction kinetics,...
Potassium ferrate [Fe(VI)] is a promising oxidant widely used in water treatment for the elimination of organic pollutants. In this work, the reaction kinetics, products, and mechanisms of the antimicrobial agent chlorophene (CP) undergoing Fe(VI) oxidation in aqueous solutions were investigated. CP is very readily degraded by Fe(VI), with the apparent second-order rate constant, k, being 423.2 M s at pH 8.0. A total of 22 oxidation products were identified using liquid chromatography-quadrupole time-of-flight-mass spectrometry , and their structures were further elucidated using tandem mass spectrometry. According to the extracted peak areas in mass spectra, the main reaction products were the coupling products (dimers, trimers, and tetramers) that formed via single-electron coupling. Theoretical calculations demonstrated that hydrogen abstraction should easily occur at the hydroxyl group to produce reactive CP· radicals for subsequent polymerization. Cleavage of the C-C bridge bond, electrophilic substitution, hydroxylation, ring opening, and decarboxylation were also observed during the Fe(VI) oxidation process. In addition, the degradation of CP by Fe(VI) was also effective in real waters, which provides a basis for potential applications.
Topics: Dichlorophen; Electrons; Iron; Kinetics; Oxidation-Reduction; Water Pollutants, Chemical; Water Purification
PubMed: 30299936
DOI: 10.1021/acs.est.8b01830 -
Environmental Science & Technology Nov 2018Reaction with soluble Mn(II) has been considered as a main decay pathway for superoxide in natural waters, accompanied by an important Mn redox cycling. In this study,...
Enhanced Removal of Chlorophene and 17β-estradiol by Mn(III) in a Mixture Solution with Humic Acid: Investigation of Reaction Kinetics and Formation of Co-oligomerization Products.
Reaction with soluble Mn(II) has been considered as a main decay pathway for superoxide in natural waters, accompanied by an important Mn redox cycling. In this study, the interaction of Mn(II) and humic acid (HA) was investigated in visible light irradiated water. Our results indicate that HA may play a dual role to act as a photosensitizer to produce superoxide anions (O) and as a strong ligand to stabilize the Mn(III), forming soluble Mn(III) species for substrate transformation. Furthermore, the reaction kinetics, products, and mechanisms of chlorophene (CP) and estradiol (E2) mixture in the Mn(II)/HA/visible light reaction systems were assessed. The removal of CP and E2 was enhanced by 24.3% and 13.2%, respectively, in mixture solution at initial concentration of 1.0 μM for each target contaminant, as compared to the case of single-compound degradation. Product identification and density functional theory calculations indicated that cross-coupling reaction of CP and E2 radicals was more likely to occur than the self-coupling reaction in mixture solution. In addition, estrogenic activities of initial reaction solution were also effectively decreased during the transformation process. These findings provide new insights into Mn(III)-mediated reactions to better understand the environmental fate of organic contaminant mixture in waters.
Topics: Dichlorophen; Estradiol; Humic Substances; Kinetics; Oxidation-Reduction; Water Pollutants, Chemical
PubMed: 30339370
DOI: 10.1021/acs.est.8b04116 -
Bioorganic & Medicinal Chemistry Letters Jul 2016Summer Gut Syndrome (SGS) is caused by various Vibrio bacterial species and can have negative effects on aquaculture farms worldwide. In New Zealand, SGS is caused by...
Summer Gut Syndrome (SGS) is caused by various Vibrio bacterial species and can have negative effects on aquaculture farms worldwide. In New Zealand, SGS is caused by Vibrio harveyii infecting King Salmon (Oncorhynchus tshawytscha). To find leads for the prevention of SGS, we screened the inhibitory effects of 16 strains of Shewanella upon V. harveyii growth in competitive solid phase cultures. The detailed investigation of Shewanella halifaxensis IRL548 revealed 2-benzyl-4-chlorophenol (1), a known, commercially available antibacterial agent, as the major bioactive component. Synthesis of a small library of congeners to confirm the natural product identity and to provide a structure-activity relationship for the observed activity was also completed. Compound 1 exhibits moderate activity against two pathogenic microorganisms.
Topics: Anti-Bacterial Agents; Dichlorophen; Dose-Response Relationship, Drug; Microbial Sensitivity Tests; Molecular Structure; Shewanella; Small Molecule Libraries; Structure-Activity Relationship; Vibrio Infections; Vibrionaceae
PubMed: 27185331
DOI: 10.1016/j.bmcl.2016.05.002 -
Environmental Technology 2015An innovative strategy integrating the use of biosurfactant (BS) and persulphate activated by chelated iron for the decontamination of soil from an emerging pollutant...
An innovative strategy integrating the use of biosurfactant (BS) and persulphate activated by chelated iron for the decontamination of soil from an emerging pollutant chlorophene was studied in laboratory down-flow columns along with other persulphate activation aids including combined application of persulphate and hydrogen peroxide, and persulphate activation with sodium hydroxide. Although BS addition improved chlorophene removal by the persulphate treatment, the addition of chelated iron did not have a significant influence. Combined application of persulphate with hydrogen peroxide resulted in a significant (p≤.05) overall improvement of chlorophene removal compared with treatment with persulphate only. The highest removal rate (71%) of chlorophene was achieved with the base-activated persulphate, but only in the upper part (of 0.0-3.5 cm in depth) of the column. The chemicals at the applied dosages did not substantially influence the Daphnia magna toxicity of the effluent. Dehydrogenase activity (DHA) measurements indicated no substantial changes in the microbial activity during the persulphate treatment. The highest oxygen consumption and a slight increase in DHA were observed with the BS addition. The combined application of persulphate and BS at natural soil pH is a promising method for chlorophene-contaminated soil remediation. Hydroquinone was identified among the by-products of chlorophene degradation.
Topics: Dichlorophen; Environmental Restoration and Remediation; Hydrogen Peroxide; Soil; Soil Pollutants; Sulfates; Surface-Active Agents
PubMed: 25514136
DOI: 10.1080/09593330.2014.948493