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1.
Int J Mol Sci ; 22(4)2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33669883

RESUMO

This study deals with the preparation of activated carbon (CDSP) from date seed powder (DSP) by chemical activation to eliminate polyaromatic hydrocarbon-PAHs (naphthalene-C10H8) from synthetic wastewater. The chemical activation process was carried out using a weak Lewis acid of zinc acetate dihydrate salt (Zn(CH3CO2)2·2H2O). The equilibrium isotherm and kinetics analysis was carried out using DSP and CDSP samples, and their performances were compared for the removal of a volatile organic compound-naphthalene (C10H8)-from synthetic aqueous effluents or wastewater. The equilibrium isotherm data was analyzed using the linear regression model of the Langmuir, Freundlich and Temkin equations. The R2 values for the Langmuir isotherm were 0.93 and 0.99 for naphthalene (C10H8) adsorption using DSP and CDSP, respectively. CDSP showed a higher equilibrium sorption capacity (qe) of 379.64 µg/g. DSP had an equilibrium sorption capacity of 369.06 µg/g for C10H8. The rate of reaction was estimated for C10H8 adsorption using a pseudo-first order, pseudo-second order and Elovich kinetic equation. The reaction mechanism for both the sorbents (CDSP and DSP) was studied using the intraparticle diffusion model. The equilibrium data was well-fitted with the pseudo-second order kinetics model showing the chemisorption nature of the equilibrium system. CDSP showed a higher sorption performance than DSP due to its higher BET surface area and carbon content. Physiochemical characterizations of the DSP and CDSP samples were carried out using the BET surface area analysis, Fourier-scanning microscopic analysis (FSEM), energy-dispersive X-ray (EDX) analysis and Fourier-transform spectroscopic analysis (FTIR). A thermogravimetric and ultimate analysis was also carried out to determine the carbon content in both the sorbents (DSP and CDSP) here. This study confirms the potential of DSP and CDSP to remove C10H8 from lab-scale synthetic wastewater.


Assuntos
Ácidos de Lewis/química , Modelos Moleculares , Naftalenos/análise , Temperatura , Compostos Orgânicos Voláteis/análise , Poluentes Químicos da Água/análise , Adsorção , Difusão , Cinética , Modelos Lineares , Nitrogênio/química , Espectrometria por Raios X , Termogravimetria , Fatores de Tempo
2.
J Chromatogr A ; 1641: 461965, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33611125

RESUMO

The injection volume and the associated column volume overload is one of the most common issues in miniaturized chromatography. The injection volume should not exceed 10% of the effective column volume. A further reduction of the injection volume leads to an increase in chromatographic efficiency. However, the signal intensity must be above a certain threshold to generate a chromatographic peak that can be detected. Therefore, the injection volume has to be optimized to reach the ideal balance between chromatographic efficiency and sensitivity. This study examined the general influence of the injection volume for both isocratic and gradient elution, depending on the retention factor and peak standard deviation. For this purpose, substances of different polarity were selected to represent a broad elution spectrum. Besides the model analyte naphthalene, these were mainly pharmaceuticals. For all measurements a microbore column with an ID of 300 µm and packed with 1.9 µm fully porous particles was used. For isocratic elution, the injection volume was varied between 4 and 16% of the effective column volume. The retention factors were adjusted between 2 and 10. For gradient elution, the injection volume was varied between 4 and 160% of the effective column volume. The observed effects were further investigated using the gradient kinetic plot theory. In isocratic elution, a loss in plate height up to 50% was observed for components that elute near the void time. A significant reduction of the chromatographic efficiency was noticed up to a retention factor of 4. In gradient elution, a reduction in peak capacity could only be observed if the injection volume exceeded 40% of the effective column volume. For some substances, only a slight loss in peak capacity was noticed even with a volume overload of 160%.


Assuntos
Cromatografia Líquida/métodos , Cinética , Metronidazol/análise , Naftalenos/análise , Porosidade , Padrões de Referência
3.
Environ Sci Technol ; 55(4): 2411-2421, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33522786

RESUMO

Polychlorinated naphthalenes (PCNs) were measured in lake trout and walleye over the period 2004-2018, utilizing isotope dilution techniques with high-resolution gas chromatography/high-resolution mass spectrometry to assess concentrations and toxic equivalence (TEQ). An age-trend model was applied to mitigate the effect of a changing lake trout age structure. Most Great Lakes Fish Monitoring and Surveillance Program sampling sites demonstrated significant half-life and percent decreases for lake trout total PCNs and total TEQ over the 2004-2018 period, the exceptions being Lake Erie lake trout and walleye which illustrated increasing concentrations. Great Lakes total PCN concentrations ranged between 5701 and 100 pg/g ww, whereas total PCN TEQ concentrations ranged between 8.89 and 0.13 pg-TEQ/g ww. Based on the average number of chlorines per naphthalene, we determined that the overall lake trout and walleye PCN congener distribution has significantly shifted to a lower-chlorinated composition in the Great Lakes (5.33 to 4.48 Cl/CN) and has resulted in a substantial 59.1% reduction of the overall total PCN TEQ burden. A prominent PCN concentration trend breakpoint was observed in Lake Ontario lake trout over the 2012-2016 period likely associated with hazardous waste cleanups, channel dredging, and spoils disposal in the Detroit River and western-basin of Lake Erie.


Assuntos
Lagos , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Great Lakes Region , Naftalenos/análise , Ontário , Truta , Poluentes Químicos da Água/análise
4.
Chemosphere ; 273: 129721, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33517113

RESUMO

This study investigates the contamination characteristics of polychlorinated naphthalenes (PCNs) in the rice paddy soils of two industrial cities (Pohang and Ulsan) in South Korea. The paddy soils were collected from 40 sites in the paddy fields near industrial complexes in both cities. The mean concentration of Σ55 PCNs was 145.9 ± 101.7 pg/g and 95.4 ± 41.4 pg/g for the soils in Pohang and Ulsan, respectively. The toxic equivalents (TEQs) of Σ28 PCNs ranged from 0.007 pg-TEQ/g to 0.069 pg-TEQ/g in Pohang, and 0.015 pg-TEQ/g to 0.046 pg-TEQ/g in Ulsan. The PCN profiles were dominated by lower chlorinated homologues such as tetra- and tri-CNs for both cities, which are associated with the historical use of technical products, or more specifically, Halowaxes (HW 1099, 1031, 1013, and 1001). The results of the principal component analysis (PCA) indicate that the historical residues from the technical products contributed to the PCN contamination, but the influence of combustion sources was also observed with a high fraction of combustion-related congeners. Based on this study, we can expect that rice grown in these paddy fields will accumulate PCNs and other combustion-related pollutants, strongly suggesting the necessity for multimedia (e.g., air, soil, water, and rice) monitoring and human exposure assessments of PCNs.


Assuntos
Naftalenos , Solo , Cidades , Monitoramento Ambiental , Humanos , Naftalenos/análise , República da Coreia
5.
Anal Chem ; 93(5): 2767-2775, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33474935

RESUMO

Clinical tissue specimens are often unscreened, and preparation of tissue sections for analysis by mass spectrometry imaging (MSI) can cause aerosolization of particles potentially carrying an infectious load. We here present a decontamination approach based on ultraviolet-C (UV-C) light to inactivate clinically relevant pathogens such as herpesviridae, papovaviridae human immunodeficiency virus, or SARS-CoV-2, which may be present in human tissue samples while preserving the biodistributions of analytes within the tissue. High doses of UV-C required for high-level disinfection were found to cause oxidation and photodegradation of endogenous species. Lower UV-C doses maintaining inactivation of clinically relevant pathogens to a level of increased operator safety were found to be less destructive to the tissue metabolome and xenobiotics. These doses caused less alterations of the tissue metabolome and allowed elucidation of the biodistribution of the endogenous metabolites. Additionally, we were able to determine the spatially integrated abundances of the ATR inhibitor ceralasertib from decontaminated human biopsies using desorption electrospray ionization-MSI (DESI-MSI).


Assuntos
Descontaminação/métodos , Raios Ultravioleta , Animais , Azetidinas/análise , Azetidinas/uso terapêutico , COVID-19/patologia , COVID-19/virologia , Neoplasias de Cabeça e Pescoço/química , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Metaboloma , Naftalenos/análise , Naftalenos/uso terapêutico , Fotólise/efeitos da radiação , Ratos , Ratos Wistar , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/efeitos da radiação , Espectrometria de Massas por Ionização por Electrospray/métodos , Terfenadina/química , Inativação de Vírus/efeitos da radiação
6.
Chemosphere ; 263: 127963, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297024

RESUMO

In this work, the performance of the atmospheric pressure chemical ionization (APCI) and photoionization (APPI) was assessed to develop a new selective and sensitive gas chromatography-high resolution mass spectrometry (GC-HRMS) method for the determination of polychlorinated naphthalenes (PCNs) in sediment samples. The capability of both APCI and APPI sources for the ionization of PCNs was investigated, showing the formation of the molecular ion and the [M‒Cl+O]‒ ion in positive and negative ion modes, respectively. Positive ion APCI provided high responses using high corona ion current, while the use of high vapour pressure dopant-solvents, such as toluene in positive mode and diethyl ether in the negative mode, was required to achieve high ionization efficiencies in APPI. The performance of the two API sources in the PCN determination by GC-HRMS were compared and the best results were achieved using the GC-APPI(+)-HRMS (Orbitrap) system. The GC-APPI(+)-HRMS (Orbitrap) method was applied to the characterization of Halowax mixtures and the analysis of marine sediments collected near to the coastal area of Barcelona (NE, Spain), demonstrating a great detection capability with low method limits of detection (0.2-1.6 pg g-1 dry weight), good precision (RSD <15%) and trueness (relative error <13%). Total PCN concentrations ranged from 0.35 to 5.0 ng g-1 dry weight and the presence of related compounds, such as polychlorinated biphenyls (PCBs), was also detected by combining positive and negative ion modes, providing complementary information to better monitor of all PCN congener groups. The results presented here show the feasibility of the GC-APPI-HRMS method for the suitable determination of PCNs.


Assuntos
Pressão Atmosférica , Naftalenos , Cromatografia Gasosa-Espectrometria de Massas , Sedimentos Geológicos , Naftalenos/análise , Espanha
7.
Int J Mol Sci ; 21(24)2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33321929

RESUMO

The consumption of synthetic cannabinoids (SCs) has significantly increased in the last decade and the analysis of SCs and their metabolites in human specimens is gaining interest in clinical and forensic toxicology. A pilot study has been carried out using a combination of an initial last generation gas chromatography-mass spectrometry (GC-MS) screening method for the determination of JWH-122, JWH-210, UR-144) in oral fluid (OF) of consumers and an ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) confirmatory method for the quantification of the parent compounds and their metabolites in the same biological matrix. OF samples were simply liquid-liquid extracted before injecting in both chromatographic systems. The developed methods have been successfully validated and were linear from limit of quantification (LOQ) to 50 ng/mL OF. Recovery of analytes was always higher than 70% and matrix effect always lower than 15% whereas intra-assay and inter-assay precision and accuracy were always better than 16%. After smoking 1 mg JWH-122 or UR-144 and 3 mg JWH-210, maximum concentration of 4.00-3.14 ng/mL JWH-122, 8.10-7.30 ng/mL JWH-210 ng/mL and 7.40 and 6.81 ng/mL UR-144 were measured by GC-MS and UHPLC-HRMS respectively at 20 min after inhalation. Metabolites of JWH 122 and 210 were quantified in OF by UHPLC-HRMS, while that of UR144 was only detectable in traces. Our results provide for the first time information about disposition of these SCs and their metabolites in consumers OF. Last generation GC-MS has proven useful tool to identify and quantify parent SCs whereas UHPLC-HRMS also confirmed the presence of SCs metabolites in the OF of SCs consumers.


Assuntos
Canabinoides/farmacocinética , Indóis/farmacocinética , Naftalenos/farmacocinética , Saliva/metabolismo , Adulto , Canabinoides/administração & dosagem , Canabinoides/análise , Cromatografia Líquida , Feminino , Humanos , Indóis/administração & dosagem , Indóis/análise , Masculino , Fumar Maconha/metabolismo , Espectrometria de Massas , Mucosa Bucal/metabolismo , Naftalenos/administração & dosagem , Naftalenos/análise , Saliva/química
8.
J Chromatogr A ; 1626: 461388, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797859

RESUMO

A reversed-phase high performance liquid chromatographic method was developed and validated for the simultaneous determination of the related substances of S-dapoxetine, including R-dapoxetine, (3S)-3-(dimethylamino-3-phenyl-1-propanol), S-3-amino-3-phenyl-1-propanol, 1-naphtol, 4-phenyl-2H,3H,4H-naphtho[1,2-b]pyran and 1-(2E)-Cinnamyloxynaphthalene. During the screening experiments seven different polysaccharide-type chiral stationary phases (amylose-based Lux-Amylose-1, Lux-i-Amylose-1 and Lux-Amylose-2, as well as cellulose-based Lux-Cellulose-1, Lux-Cellulose-2, Lux-Cellulose-3 and Lux-Cellulose-4) were tested in polar organic mode using a mobile phase consisting of 0.1% diethylamine in methanol, ethanol, 2-propanol and acetonitrile with 0.5 mL min-1 flow rate at 20 °C. Best results were obtained on Lux Cellulose-3 column with the ethanol-based mobile phase. To increase the retention factor of two, early-eluting impurities, water was added to the mobile phase. In order to counterbalance the increased total analysis time, higher column temperature (40 °C) and gradient elution, combined with flow-programming` was applied. Using the optimized conditions baseline separations were achieved for all compounds within 30 min. The method was validated according to the International Council on Harmonization guideline Q2(R1) and applied to the analysis of an approved, tablet formulation and dapoxetine-containing products sold on the internet. As expected, in the case of the pharmacy-acquired product, all of the monitored impurities were below 0.1%. However, interesting results were obtained when internet-acquired samples were analyzed. These tablets contained racemic dapoxetine and/or high concentration of R-dapoxetine impurity. Based on this work polysaccharide-based chiral stationary phases can be successfully applied for the simultaneous determination of achiral and chiral impurities in reversed-phase mode applying gradient elution and flow-rate programs. The study further underlines the importance of not only achiral, but also enantiomeric quality control, whenever counterfeiting of a single enantiomeric agent is suspected.


Assuntos
Benzilaminas/análise , Cromatografia Líquida de Alta Pressão/métodos , Naftalenos/análise , Cromatografia de Fase Reversa , Limite de Detecção , Espectrometria de Massas , Preparações Farmacêuticas/química , Estereoisomerismo , Comprimidos/química , Temperatura
9.
Ecotoxicol Environ Saf ; 201: 110860, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32563162

RESUMO

The biodegradation of naphthalene using low-density polyethylene (LDPE) immobilized Exiguobacterium sp. RKS3 (MG696729) in a packed bed bioreactor (PBBR) was studied. The performance of a continuous PBBR was evaluated at different inlet flow rates (IFRs) (20-100 mL/h) under 64 days of operation. The maximum naphthalene removal efficiency (RE) was found at low IFR, and it further decreased with increasing IFRs. In a continuous PBBR, the external mass transfer (EMT) aspect was analysed at various IFRs, and experimental data were interrelated between Colburn factor (JD) and Reynolds number (NRe) as [Formula: see text] . A new correlation [Formula: see text] was obtained to predict the EMT aspect of naphthalene biodegradation. Andrew-Haldane model was used to evaluate the bio-kinetic parameters of naphthalene degradation, and kinetic constant νmax, Js, and Ji were found as 0.386 per day, 13.6 mg/L, and 20.54 mg/L, respectively.


Assuntos
Reatores Biológicos/microbiologia , Naftalenos/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Bacillales/crescimento & desenvolvimento , Bacillales/metabolismo , Biodegradação Ambiental , Células Imobilizadas/microbiologia , Cinética , Polietileno/química
10.
Environ Pollut ; 262: 114267, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32179224

RESUMO

Multiple types of persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and hexachlorobenzene (HCB), can be unintentionally released from combustion or thermal industrial processes, which are speculated to be the main sources of these contaminants, as they were banned on production and use since several decades ago. In this study, concentrations and sources of 40 PCBs, 39 PCNs, and HCB were analyzed in air samples collected during the period 2012-2015 at a background site in east China. ΣPCBs, ΣPCNs, and HCB were in the range of 9-341 pg/m3, 6-143 pg/m3, and 14-522 pg/m3, respectively. Seasonal characteristics with high levels in winter and low levels in summer were observed for PCNs and HCB. PCBs also exhibited slightly higher levels in winter. Source apportionment was conducted, using polycyclic aromatic hydrocarbons (PAHs) as combustion sources indicator, combined with principal component analysis (PCA) and positive matrix factorization (PMF) model. The results indicated that the legacy of past produced and used commercial PCBs was the dominant contributor (∼56%) to the selected PCBs in the atmosphere in east China. PCNs were mainly emitted from combustion sources (∼64%), whereas HCB almost entirely originated from combustion process (>90%).


Assuntos
Poluentes Atmosféricos/análise , Bifenilos Policlorados/análise , Atmosfera , China , Monitoramento Ambiental , Hexaclorobenzeno , Naftalenos/análise
11.
Environ Pollut ; 259: 113838, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32023785

RESUMO

To date limited information's are available concerning unintentional productions, screening, profiling, and health risks of polychlorinated naphthalenes (PCNs) in ambient environment and occupational environment. Literature reveals that dust is a neglected environmental matrix never measured for PCNs. To our knowledge, this is the first study to investigate the concentrations and health risks of PCNs in indoor dust, air, and blood of major e-waste recycling hubs in Pakistan. Indoor air (n = 125), dust (n = 250), and serum (n = 250) samples were collected from five major e-waste hubs and their vicinity to measure 39 PCN congeners using GC-ECNI-MS. ∑39PCN concentrations in indoor air, dust, and serum (worker > resident > children) samples ranged from 7.0 to 9583 pg/m3, from 0.25 to 697 ng/g, and from 0.15 to 401 pg/g lipid weight, respectively. Predominant PCN congeners in indoor air and dust were tri- and tetra-CNs, while tetra- and penta-CNs were dominant in human serum samples. The higher PCNs contribution was recorded at the recycling units, while the lower was observed at the shops of the major e-waste hubs. Higher contribution of combustion origin CNs in air, dust and human samples showed combustion sources at the major e-waste hubs, while Halowax and Aroclor based technical mixture showed minor contribution in these samples. Mean toxic equivalent (TEQ) concentrations of PCNs were 2.79E+00 pg-TEQ/m3, 1.60E-02 ng-TEQ/g, 8.11E-01 pg-TEQ/g, 7.14E-01 pg-TEQ/g, and 6.37E-01 pg-TEQ/g for indoor air, dust, and serum samples from workers, residents, and children, respectively. In our study, CNs- 66/67 and -73 in indoor air, dust, and human serum were the great contributors to total TEQ concentrations of PCNs. This first base line data directs government and agencies to implement rules, regulation to avoid negative health outcomes and suggests further awareness in regard of provision of proper knowledge to the target population.


Assuntos
Resíduo Eletrônico , Exposição Ambiental , Naftalenos , Criança , Poeira , Resíduo Eletrônico/efeitos adversos , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental , Humanos , Naftalenos/análise , Naftalenos/química , Naftalenos/toxicidade , Paquistão , Medição de Risco
12.
Environ Pollut ; 260: 114035, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32041023

RESUMO

Edible cod liver products including cod liver oil and canned cod liver, sampled over the last five decades from the North Atlantic region, including the Baltic Sea were analysed for a set of persistent and toxicologically significant polychlorinated naphthalene (PCN) congeners with some of the highest relative potencies (dioxin-like toxicity) among PCNs. The targeted congeners showed a near-universality of occurrence in all samples apart from the most recent sample of cod liver oil which was assumed to be highly purified, as cod livers from the same period and location showed appreciable amounts of PCNs. The majority of dominant congeners in legacy technical PCN mixtures were absent or occurred in low concentrations, raising the possibility that congeners arising from combustion related sources may be acquiring a greater significance following the decline and elimination of PCN production. The apparent appreciation in the relative amounts of PCN#70 in the last three to four decades may provide support for this view. The PCN contribution to dioxin-like toxic equivalence (TEQ) that was estimated for these samples (range 1.2-15.9 pg TEQ g-1) was significant in comparison to the EU regulated value of 1.75 pg TEQ g-1 for dioxins in fish oils. Most of the TEQ was associated with PCNs 66/67, 64/68, 69 and 73. Although metabolic processes are likely to influence this distribution, the profile is a little different to that observed in the tissues of higher order animals where PCNs #66/67 and #73 may contribute approximately 90% to the summed TEQ.


Assuntos
Contaminação de Alimentos/estatística & dados numéricos , Naftalenos/análise , Animais , Países Bálticos , Dioxinas , Fígado , Bifenilos Policlorados , Dibenzodioxinas Policloradas
13.
Artigo em Inglês | MEDLINE | ID: mdl-31913782

RESUMO

A stain of Pseudomonas sp. Lphe-2, which could degrade phenanthrene as the main carbon and energy source, was isolated from the aerobic sludge of a coking plant. Then its biodegradation characteristics, whole genome sequence and biodegradation pathway were examined. The Lphe-2 strain exhibited broad-spectrum degradation activities for various polycyclic aromatic hydrocarbons (PAHs), including naphthalene (NAP), phenanthrene (PHE), and pyrene (PYR). Under the optimal conditions, the degradation efficiency of phenanthrene (100 mg/L) is 92.76% on the 7th day, and 2-carboxybenzaldehyde and 1-hydroxy-2-naphthoic acid are the major metabolites found in phenanthrene metabolism. Genomic analysis of Pseudomonas sp. Lphe-2 showed that a total of 3879 genes from the Lphe-2 strain were annotated based on the COG classification, and the genomic information was annotated to 185 metabolic pathways. Based on the intermediate metabolites detected by Gas Chromatography-Mass Spectrometer (GC-MS) and all potential phenanthrene-degrading genes identified by BLAST search, a phenanthrene biodegradation pathway of Lphe-2 strain was proposed. These results suggested that Lphe-2 strain has a good prospect in the bioremediation of PAHs pollution.


Assuntos
Genes Bacterianos , Fenantrenos/análise , Pseudomonas/metabolismo , Esgotos/microbiologia , Poluentes do Solo/análise , Biodegradação Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Genômica , Redes e Vias Metabólicas/genética , Anotação de Sequência Molecular , Naftalenos/análise , Naftalenos/metabolismo , Fenantrenos/metabolismo , Pseudomonas/genética , Pirenos/análise , Pirenos/metabolismo , Poluentes do Solo/metabolismo
14.
Work ; 65(2): 377-390, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31985480

RESUMO

BACKGROUND: The aim of this study was to characterize solid particulate aerosol derived from a cutlery microenterprise and to investigate substances associated with activities performed within the work environment. OBJECTIVE: Suspended particulate matter (SPM) was collected at different locations in the cutlery workshop and near machines used by workers, using passive sampling devices fitted with polytetrafluoroethylene filters, onto which total particulate material was deposited. The substances present in the SPM were analyzed using gas chromatography-mass spectrometry (GC-MS). RESULTS: Identification of the substances was performed using the National Institute of Standards (NIST) library and automated mass spectral deconvolution and identification system. (AMDIS) software, considering at least 70% probability. The concentration of total dust, obtained using a gravimetric method, was approximately 1 mg.m-3. CONCLUSION: The toxic substances found in the SPM included halogenated hydrocarbons (containing chlorine, fluorine, and iodine) and aromatic hydrocarbons. The toxic substances included naphthalene, which is classified as carcinogenic.


Assuntos
Hidrocarbonetos Aromáticos/análise , Hidrocarbonetos Halogenados/análise , Material Particulado/análise , Poluentes Ocupacionais do Ar/análise , Brasil , Cromatografia Gasosa-Espectrometria de Massas , Utensílios Domésticos , Naftalenos/análise , Empresa de Pequeno Porte
15.
Molecules ; 25(2)2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31941089

RESUMO

Red yeast rice dietary supplements (RYR DS) are largely sold in Western countries for their cholesterol-lowering/regulating effect due to monacolins, mainly monacolin K (MK), which is, in fact, lovastatin, the first statin drug on the market. 1H-NMR was used as an easy, rapid and accurate method to establish the chemical profiles of 31 RYR DS and to quantify their monacolin contents. Among all the 1H resonances of the monacolins found in RYR, only those of the ethylenic protons of the hexahydronaphthalenic ring at 5.84 and 5.56 ppm are suitable for quantification because they show no overlap with the matrix signals. The total content in monacolins per capsule or tablet determined in 28 DS (the content in 3 DS being below the limit of quantification of the method, ≈ 0.25 mg per unit dose) was close to that measured by UHPLC, as shown by the good linear correlation between the two sets of values (slope 1.00, y-intercept 0.113, r2 0.986). Thirteen of the 31 RYR DS analyzed (i.e., 42%) did not provide label information on the concentration of monacolins and only nine of the 18 formulations with an indication (i.e., 50%) actually contained the declared amount of monacolins.


Assuntos
Produtos Biológicos/análise , Suplementos Nutricionais/análise , Naftalenos/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Ressonância Magnética Nuclear Biomolecular
16.
Chemosphere ; 243: 125443, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995890

RESUMO

Long-term sampling is essential for monitoring the air pollutants emitted from stack since it can monitor the pollutants emission continuously including the stages of start-up, shutdown and normal operation. However, commercial continuous sampling equipment such as AMESA faces the challenges of high weight and complicated sampling procedures. This study has developed a long-term and automatic sampling system (National Central University continuous stack sampling system, NCU-CS3), and compared the efficiency with manual sampling train (MST). The results indicate that relative standard deviation (RSD) of PCDD/Fs concentrations measured between NCU-CS3 and MST is <20%, demonstrating that the difference between NCU-CS3 and MST in measuring PCDD/Fs is insignificant. Besides, the effects of adsorbent temperature, adsorbent amount and type of adsorbent on breakthroughs of PAHs and unintentional-persistent organic pollutants (UPOPs) such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), chlorinated phenols (CPs), chlorinated benzenes (CBs) and polychlorinated naphthalenes (PCNs) are evaluated. The results indicate that the breakthrough of pollutants increases with increasing temperature of XAD-2 and decreases with increasing XAD-2 amount. Moreover, XAD-4 is used as alternative adsorbent to test the breakthrough and the results indicate that the breakthroughs of UPOPs of XAD-4 as adsorbent are lower than that with XAD-2 due to higher specific surface area of XAD-4. Furthermore, the residual of PCDD/Fs with NCU-CS3 as the sampling train is relatively low (1.5-3.8%), which meets the regulation of EN 1948-5 (10%).


Assuntos
Poluentes Atmosféricos/análise , Dibenzofuranos Policlorados/análise , Monitoramento Ambiental/métodos , Compostos Orgânicos/análise , Dibenzodioxinas Policloradas/análise , Benzofuranos/análise , Dibenzofuranos/análise , Poluentes Ambientais/análise , Estudos Longitudinais , Naftalenos/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
17.
Environ Sci Pollut Res Int ; 27(3): 3329-3337, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31838706

RESUMO

Naphthalene (NAP) is found as a pollutant in water, soil, and air, and adsorption is the most prominent removal process of this compound, among the methods studied. A study concerning the types of adsorbents and the parameters with the greatest influence on the adsorption process is interesting to direct future works on new adsorbents. The use of multivariate data analysis tools becomes an appealing way to compile data obtained from bibliographic reviews and to establish a behavior in NAP adsorption. This work aims to evaluate the parameters with greater influence on NAP adsorption process regarding adsorption capacity (qeexp) with the principal component analysis (PCA), and to group common NAP adsorbents by chemical characteristics through hierarchical cluster analysis (HCA). The variables qeexp, S, [NAP]0, T, CT, and [Ads] were used to perform PCA with correlation matrix. For the HCA, the variables S, [NAP]0, T, CT, and [Ads] with average linkage method (UPGMA) and Euclidean distance were used. Through PCA, it is possible to infer that S and [NAP]0 are the factors with greater influence in qeexp of NAP, while T, CT, and [Ads] have little correlation. PCA also shows that activated charcoal is the adsorbent with higher qeexp. HCA grouped the adsorbents into four groups by their chemical classes, except group A. Both PCA and HCA methods show themselves as potential tools to evaluate a data set of NAP adsorption processes.


Assuntos
Carvão Vegetal/química , Naftalenos , Poluentes Químicos da Água , Adsorção , Análise Multivariada , Naftalenos/análise , Naftalenos/química , Água
18.
Chemosphere ; 243: 125427, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31778917

RESUMO

The quantization parameters, infrared and Raman spectra of 75 polychlorinated naphthalenes (PCNs) and 42 environmentally friendly CN-56 (CN-56: No. 56 PCN molecule; 1, 2, 3, 7, 8-PentaCN) molecules that are easier to degrade were first calculated via the density functional theory (DFT) method, and the structural characteristics of the molecules were analysed to obtain the substituent characteristics. The principal component analysis method was used to systematically analyse and summarize the effects of macroscopic substituent characteristics, microscopic quantitative parameters and spectral information on the biodegradability of PCNs and 42 environmentally friendly CN-56 molecules, and then the quantitative structure-activity relationship (QSAR), molecular docking and molecular dynamics simulation methods were used to further investigate the biodegradation mechanism from the perspective of molecules and protein receptors. The results showed that PCNs and new PCNs extracted 5 and 6 principal components from 21 kinds of original parameter indicators, respectively, which can effectively explain the original variable information. Besides that, electrostatic activity is the primary factor affecting the degradation of PCNs; reducing the para-substitution logarithm or increasing the total number of substituents and introducing electrostatic groups in the ortho or meta position of PCN molecules can design new PCN derivatives with higher degradability; enhancing the irradiation of Raman light or reducing the irradiation of infrared light properly can increase the biodegradation rate of PCN molecules.


Assuntos
Biodegradação Ambiental , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Naftalenos/metabolismo , Análise de Componente Principal , Relação Quantitativa Estrutura-Atividade , Naftalenos/análise , Espectrofotometria Infravermelho , Análise Espectral Raman
19.
Ecotoxicol Environ Saf ; 188: 109895, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31706238

RESUMO

Seventeen soil samples collected in an industrial park located in Ningxia Province, Northwestern China were analyzed for polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). The PCN, PCDD/F, and PCB concentration ranges were 183-3340, 7.00-215, and 45.1-355 pg/g, respectively. Positive matrix factorization showed that secondary ferrous metal smelters and cement kilns contributed more than 70% of the total PCN concentration. Historical use of Halowax 1051 also affected the PCN concentrations in soil. Principal component analysis indicated that the PCDD/F concentrations in soil in the study area were mainly affected by thermal processes in secondary ferrous metal smelters. CB-209 was an important contributor to total PCBs in the study area, and likely originated from the phthalocyanine-type pigments used in a local recycled paper mill. Samples S10, S1, S17, and S6 had high ∑TEQ (PCDD/Fs + PCNs + PCBs) concentrations, and the carcinogenic risks of PCDD/Fs, PCNs, and PCBs for workers from these samples were 0.487 × 10-6, 0.234 × 10-6, 0.230 × 10-6, and 0.210 × 10-6, respectively. According to our results, the health risks of PCDD/Fs, PCNs, and PCBs for workers in this area should be given more attention.


Assuntos
Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Indústrias , Naftalenos/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , China , Humanos , Medição de Risco , Solo/química
20.
Ecotoxicol Environ Saf ; 189: 110051, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31812022

RESUMO

Naphthalene has remained a challenge how to eradicate it from the water because of its carcinogenic risk to humans. In the present study, naphthalene prominently increased the rates of embryonic mortality and malformation, and decreased the hatchability of zebrafish which have a high developmental similarity to humans. Moreover, multiple-organ toxicity were notably found in naphthalene-treated zebrafish. Here, irradiated graphene aerogel (IGA) was successfully prepared from high-energy electron beam to generate more wrinkles, folds, defects and a strong absorption capability for naphthalene, compared with the non-irradiated graphene aerogel. IGA was outstandingly found to remove naphthalene from the embryo culture medium, and subsequently inhibit the embryotoxicity and maintain tissue integrity by restoring cardiac function, attenuating apoptosis signals, recovering eye morphology and structure, reducing expression of heat shock protein 70 in the tissues and promoting behavioral capacity. Meanwhile, no obvious negative impact of IGA was found in the developing zebrafish from embryo to larvae. Consequently, reduction in the toxicity of naphthalene during zebrafish embryogenesis was mediated by IGA as an advanced strategy.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Grafite/química , Naftalenos/análise , Poluentes Químicos da Água/análise , Peixe-Zebra , Animais , Grafite/efeitos da radiação , Grafite/toxicidade , Hidrogéis , Larva/efeitos dos fármacos , Naftalenos/toxicidade , Propriedades de Superfície , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade
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