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1.
Chemosphere ; 254: 126815, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957269

RESUMO

A revised Community Multi-scale Air Quality (CMAQ) model with updated secondary organic aerosol (SOA) yields and a more detailed description of SOA formation from isoprene (ISOP) oxidation was applied to study the spatial distribution of SOA, its components and precursors in Shaanxi in July of 2013. The emissions of biogenic volatile organic compounds (BVOCs) were generated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN), of which ISOP and monoterpene (MONO) were the top two, with 1.73 × 109 mol and 1.82 × 108 mol, respectively. The spatial distribution of BVOCs emission was significantly correlated with the vegetation coverage distribution. ISOP and its intermediate semi-volatile gases were up to ∼7.0 and ∼1.4 ppb respectively in the ambient. SOA was generally 2-6 µg/m3, of which biogenic SOA (BSOA) accounted for as high as 84% on average. There were three main BVOCs Precursors including ISOP (58%) and MONO (8%) emit in the studied domain, and ISOP (9%) transported. The Guanzhong Plain had the highest BSOA concentrations of 3-5 µg/m3, and the North Shaanxi had the lowest of 2-3 µg/m3. More than half of BSOA was due to reactive surface uptake of ISOP epoxide (0.2-0.7 µg/m3, ∼19%), glyoxal (GLY) (0.2-0.5 µg/m3, ∼11%) and methylglyoxal (MGLY) (0.4-1.4 µg/m3, ∼32%), while the remaining was due to the traditional equilibrium partitioning of semi-volatile components (0.1-1.2 µg/m3, ∼25%) and oligomerization (0.2-0.4 µg/m3, ∼12%). Overall, SOA formed from ISOP contributed 1-3 µg/m3 (∼80%) to BSOA.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Poluição do Ar , Butadienos , China , Hemiterpenos , Monoterpenos/análise , Compostos Orgânicos Voláteis/análise
2.
Zhongguo Zhong Yao Za Zhi ; 45(16): 3857-3862, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32893581

RESUMO

Licorice is one of the most commonly used traditional Chinese medicine. In clinic, raw licorice and honey-fried licorice are used in medicines, with the main effects in clearing away heat and detoxifying, moistening lungs and removing phlegm. Honey-fried licorice has effects in nourishing the spleen and stomach and replenishing Qi and pulse. Because traditional Chinese medicine exerts the effects through multiple components and multiple targets, the index components used in the quality evaluation of licorice are often difficult to reflect their real quality. In addition, most of studies for the quality standards have shown that honey-fried licorice are the same as licorice, with a lack of quality evaluation standards that can demonstrate their processing characteristics. The quality of medicine is directly related to its clinical efficacy, so it is necessary to establish a more effective quality control method. Licorice has a beany smell, which is one of the main quality identification characteristics. In this study, by taking advantage of the odor characteristics, a headspace-gas chromatography-ion migration mass spectrometry technology was used to establish a quality evaluation method. A total of 76 volatile components were identified. Through the dynamic principal component analysis, 7 kinds of volatile substances in raw licorice and 13 kinds of volatile substances in honey-fried licorice were statistically obtained, and could be taken as index components for the quality evaluation of raw and honey-fried licorice, respectively. This study could help realize the combination and unification of modern detection and traditional quality evaluation methods, and make a more realistic evaluation for the quality of licorice.


Assuntos
Glycyrrhiza , Mel/análise , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Mobilidade Iônica
3.
J Environ Sci (China) ; 97: 25-34, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32933737

RESUMO

Shijiazhuang, the city with the worst air quality in China, is suffering from severe ozone pollution in summer. As the key precursors of ozone generation, it is necessary to control the Volatile Organic Compounds (VOCs) pollution. To have a better understanding of the pollution status and source contribution, the concentrations of 117 ambient VOCs were analyzed from April to August 2018 in an urban site in Shijiazhuang. Results showed that the monthly average concentration of total VOCs was 66.27 ppbv, in which, the oxygenated VOCs (37.89%), alkanes (33.89%), and halogenated hydrocarbons (13.31%) were the main composite on. Eight major sources were identified using Positive Matrix Factorization modeling with an accurate VOCs emission inventory as inter-complementary methods revealed that the petrochemical industry (26.24%), other industrial sources (15.19%), and traffic source (12.24%) were the major sources for ambient VOCs in Shijiazhuang. The spatial distributions of major industrial activities emissions were identified by using geographic information statistics system, which illustrated the VOCs was mainly from the north and southeast of Shijiazhuang. The inverse trajectory analysis using Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) and Potential Source Contribution Function (PSCF) clearly demonstrated the features of pollutant transport to Shijiazhuang. These findings can provide references for local governments regarding control strategies to reduce VOCs emissions.


Assuntos
Poluentes Atmosféricos/análise , Compostos Orgânicos Voláteis/análise , China , Cidades , Monitoramento Ambiental , Emissões de Veículos/análise
5.
Ecotoxicol Environ Saf ; 203: 111027, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888595

RESUMO

The available evidence on the indoor air quality of operating rooms (ORs) in the Low- and Middle-income Countries (LMICs) is very scarce. Moreover, there is no study on the comparing the concentration of indoor air pollutants in different ORs. Therefore, this study aimed to measure and compare the benzene, toluene, ethylbenzene and xylene (BTEX) concentrations in the air of different ORs in hospitals of Sabzevar, Iran. Moreover, carcinogenic and non-carcinogenic risk of exposure to these pollutants were assessed using Monte Carlo simulations technique. This cross-sectional study was based on volatile organic compounds (VOCs) passive sampling of eight ORs including General surgery, Curettage, Eye surgery, Neurosurgery, Orthopedic, Laparoscopic, Cesarean and Ear, nose, throat (ENT) in two monthly campaigns from November 2019 to February 2020. One-way ANOVA and Post-hoc analyses were used to compare the concentration of BTEX compounds in different ORs. The overall mean (standard deviation (SD)) of benzene, toluene, ethylbenzene, xylene and total BTEX concentrations were 10.0 (1.8), 7.2 (1.9), 1.8 (0.6), 0.4 (0.2) and 19.4 (4.1) µg/m3. The Curettage OR had the highest (12.93 µg/m3) and ENT OR had the lowest (7.42 µg/m3) benzene concentrations. The highest concentrations of toluene, ethylbenzene and total BTEX were observed in General surgery OR. The cancer risks of exposure to benzene in all ORs were higher than the acceptable range recommended by Unite State Environmental Protection Agency (USEPA, 1 × 106). However, the hazard quotient (HQ) values for all ORs were at safe level (HQ < 1). Overall, our study suggested that the concentrations of BTEX compounds were significantly difference in different ORs and benzene had a carcinogenic risk for personnel and surgical staff in different ORs.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Salas Cirúrgicas/normas , Fumaça/análise , Compostos Orgânicos Voláteis/análise , Benzeno/análise , Derivados de Benzeno/análise , Carcinógenos/análise , Estudos Transversais , Monitoramento Ambiental/métodos , Humanos , Irã (Geográfico) , Tolueno/análise , Xilenos/análise
6.
Environ Monit Assess ; 192(10): 634, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32909141

RESUMO

Volatile organic compounds, VOCs, are air pollutants widely produced by biogenic and anthropogenic sources. This work quantitatively studied the presence of these gases in the internal and external environments of schools, comparing one in an urban area (La Salle School, Canoas, RS) and another in a rural area (Santa Cassia Farm School, Nova Santa Rita, RS). The aim of this study was to compare if this environmental differences (location) influence their gases concentration. Monitoring campaigns were conducted for 6 months, occurring every 2 weeks in both schools during class hours, 1 day indoors and 1 day outdoors. The results showed higher concentrations of total volatile organic compounds in the urban school external environment compared with the same rural school environment and, in the comparison between environments, the internal environments of the two schools obtained higher VOC concentrations than the external ones, except in November and December at the urban school.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Compostos Orgânicos Voláteis/análise , Brasil , Monitoramento Ambiental , Humanos
7.
J Chromatogr A ; 1626: 461363, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797842

RESUMO

Analytical techniques to determine volatile compounds such as flavor, aroma, and fragrances are in high demand due to their wide range of applications in industry, the chemical properties of them are very diverse. Supercritical fluid chromatography (SFC) is capable of high speed, high peak capacity separation and has a high separation coverage. It is also an advantageous for preparative purifications due to its unique mobile phase conditions. However, there is no column commercially available for SFC that is suitable to comprehensively separate volatile compounds. SFC is limited to the use of silica-based columns due to weak retentions and polymer-based column issues such as pressure, swelling and shrinkage tolerances. This study demonstrated comprehensive analytical method for volatile in SFC using a highly cross-linked styrene divinylbenzene (SDVB) polymer-based column, newly developed for SFC. In this study, 23 typical volatile compounds with a wide variety of chemical properties were selected as model compounds. The newly developed SDVB column showed, compared to conventional silica-based columns (k > 0.3), an excellent overall and substantial improved retentions (k > 1.6) under SFC mobile phase conditions. It was also able to retain esters (hydroxy acetate, pentyl butylate, methyl salicylate) and non-polar terpenes (limonene, pinene) that did not show sufficient retention in any other commercially available silica-based columns. Aldehydes reacting on NH2 column due to Schiff base formation were also successfully eluted. It was confirmed that SDVB column provided comprehensive separation and wide coverage for volatile compounds.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Poliestirenos/química , Compostos de Vinila/química , Espectrometria de Massas , Dióxido de Silício , Terpenos/isolamento & purificação , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação
8.
J Environ Sci (China) ; 96: 138-150, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819688

RESUMO

Speciated characterization of Volatile Organic Compounds (VOCs), including oxygenated VOCs (OVOCs), from construction machinery and river ships in China is currently lacking. In this regard, we conducted field measurement on speciated VOC (including OVOC) emissions from six construction machinery and five river ships in the Pearl River Delta (PRD) region to identify VOC emission characteristics. We noticed that OVOC emissions from construction machinery and ships accounted for more than 50% of the total VOC emissions, followed by alkenes, aromatics and alkanes. Formaldehyde and acetaldehyde were the most emission species, accounting for 61.8%-83.2% of OVOCs. For construction machinery, the fuel-based emission factors of roller, grader and pile driver were 3.12, 3.12 and 7.36 g/kg, respectively. With the rigorous restraint by the national emission standards, VOC emissions of construction machinery had decreased considerably, especially during stage Ⅲ. Ozone formation potential was also significantly reduced due to the significant decrease in emissions of OVOCs and alkenes with higher reactivity. For river ships, the fuel-based emission factors of cargo ships and speedboat were 1.46 and 0.44 g/kg, respectively. VOC emissions from construction machinery and river ships in Guangdong Province in 2017 were 8851.0 and 4361.0 ton, respectively. This study filled the knowledge gaps of reactive gas emissions from different kinds of non-road mobile sources over the PRD, and more importantly, highlighted the necessity in adding OVOC measurement to give a complete and accurate depiction of reactive gas emissions from non-road mobile sources.


Assuntos
Poluentes Atmosféricos/análise , Ozônio/análise , Compostos Orgânicos Voláteis/análise , China , Monitoramento Ambiental , Rios , Navios , Emissões de Veículos/análise
9.
J Chromatogr A ; 1626: 461369, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797848

RESUMO

Pumped sorbent tube sampling is a well established method for the sampling of volatile organic compounds (VOCs) and semi volatile organic compounds (SVOCs) in ambient, indoor and workplace atmospheres1. Safe sampling volumes and breakthrough volumes have been published for commonly found VOCs on widely used sorbents such as Tenax, however for newer sorbents and less commonly found VOCs there is less robust data. The Safe Sampling Volumes (SSVs) were determined from 15 tests of Retention Volume on 12 VOCs across the 3 sorbents. VOCs tested were: Aldehydes (C5, C6, C8, C9), Ketones (C4, C6), Alcohols (C3, C4), Furan, Limonene, Isoprene and Ethyl Acetate. 12 VOC / sorbent combinations gave SSVs large enough for practical sampling of indoor atmospheres, while SSVs for Furan on Carbopack-X, Isovaleraldehyde on Tenax TA and Methyl Ethyl Ketone on Tenax TA gave SSVs that were too small to be of practical use. This work identifies suitable sorbents and sampling volumes for the complete range of species tested.


Assuntos
Cromatografia Gasosa/métodos , Polímeros/química , Compostos Orgânicos Voláteis/análise , Adsorção , Poluição do Ar em Ambientes Fechados/análise , Aldeídos/química , Monitoramento Ambiental , Furanos/química , Compostos Orgânicos Voláteis/química
10.
J Chromatogr A ; 1626: 461389, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797860

RESUMO

The reliable measurement of very volatile organic compounds (VVOC) in indoor air by use of thermal desorption gas chromatography (TD-GC) in order to include them into evaluation schemes for building products even nowadays is a great challenge. For capturing these small molecules with carbon numbers ranging from C1C6, strong adsorbents are needed. In the present study, recovery rates of nine suitable adsorbents of the groups of porous polymers, graphitised carbon blacks (GCB) and carbon molecular sieves (CMS) are tested against a complex test gas standard containing 29 VVOC. By consideration of the recovery and the relative humidity (50% RH), combinations of the GCB Carbograph 5TD, the two CMS Carboxen 1003 and Carbosieve SII as well as the porous polymer Tenax® GR were identified to be potentially suitable for sampling the majority of the VVOC out of the gas mix. The results reveal a better performance of the adsorbents in combination than being used alone, particularly under humid sampling conditions. The recovery rates of the chosen compounds on each adsorbent should be in the range of 80-120%.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos Voláteis/análise , Adsorção , Carbono/química , Gases/química , Umidade , Polímeros/química , Temperatura
11.
Chemosphere ; 260: 127589, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32682135

RESUMO

Although recycled plastics provide a low-cost and environmentally friendly alternative for many applications, their desirability is significantly limited by the presence of unpleasant odors from volatile organic compounds (VOCs). In this work, a headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) method was optimized to analyze volatile compounds from an odorous recycled plastic resin which was roughly composed of 85-90% polypropylene (PP) and 15-10% high-density polyethylene (HDPE). A large variety of aliphatic hydrocarbons and 13 additive residues were detected. Statistical tools were employed to screen the VOCs and successfully identified three components, i.e., 2,4-dimethyl-heptane, 4-methyl-octane and octamethylcyclotetrasiloxane (D4), which were significantly related to the odor intensity of the recycled plastic resin (p-values < 0.05). 2,4-Dimethyl-heptane has a strong, pungent plastic smell, which is very similar to the odor of the recycled resin. It is identified as a major source of the odor. Past relevant research has not been able to establish a direct link between an odorous compound and the undesirable odor of recycled plastic until now. 4-Methyl-octane was highly corelated to 2,4-dimethyl-heptane and somewhat contributed to the odor. D4 does not have an odor, but it may serve as an indicator of some odorous residues from personal care products.


Assuntos
Odorantes/análise , Resinas Sintéticas/química , Microextração em Fase Sólida/métodos , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Plásticos/química , Polietileno/química , Polipropilenos/química , Reciclagem
12.
Sci Rep ; 10(1): 11746, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678173

RESUMO

Category A and B biothreat agents are deemed to be of great concern by the US Centers for Disease Control and Prevention (CDC) and include the bacteria Francisella tularensis, Yersinia pestis, Burkholderia mallei, and Brucella species. Underscored by the impact of the 2020 SARS-CoV-2 outbreak, 2016 Zika pandemic, 2014 Ebola outbreak, 2001 anthrax letter attacks, and 1984 Rajneeshee Salmonella attacks, the threat of future epidemics/pandemics and/or terrorist/criminal use of pathogenic organisms warrants continued exploration and development of both classic and alternative methods of detecting biothreat agents. Volatile organic compounds (VOCs) comprise a large and highly diverse group of carbon-based molecules, generally related by their volatility at ambient temperature. Recently, the diagnostic potential of VOCs has been realized, as correlations between the microbial VOC metabolome and specific bacterial pathogens have been identified. Herein, we describe the use of microbial VOC profiles as fingerprints for the identification of biothreat-relevant microbes, and for differentiating between a kanamycin susceptible and resistant strain. Additionally, we demonstrate microbial VOC profiling using a rapid-throughput VOC metabolomics method we refer to as 'simultaneous multifiber headspace solid-phase microextraction' (simulti-hSPME). Finally, through VOC analysis, we illustrate a rapid non-invasive approach to the diagnosis of BALB/c mice infected with either F. tularensis SCHU S4 or Y. pestis CO92.


Assuntos
Metabolômica/métodos , Tularemia/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Animais , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Surtos de Doenças , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Feminino , Francisella tularensis/efeitos dos fármacos , Francisella tularensis/isolamento & purificação , Francisella tularensis/metabolismo , Canamicina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Microextração em Fase Sólida , Tularemia/microbiologia , Tularemia/patologia , Tularemia/veterinária , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Yersinia pestis/efeitos dos fármacos , Yersinia pestis/isolamento & purificação , Yersinia pestis/metabolismo
13.
Huan Jing Ke Xue ; 41(7): 3056-3065, 2020 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608877

RESUMO

To understand the characteristics and potential hazards of volatile organic compounds (VOCs) emitted from different industrial factories in Zhengzhou, several representative factories have been selected for sample collection using canisters; the samples were subsequently analyzed by GC-MS/FID system, from which the composition and risk of VOCs are discussed in this study. It was found that OVOCs, especially ethyl acetate and isopropanol, were the most important species originating from printing factories, which accounted for more than 93.1% of total VOCs. The major components related to manufacturing industries, including automobile, furniture, and coating, were aromatics, mainly m/p-xylene, o-xylene, and ethylbenzene, which contributed 33.5%-90.0% to VOCs. Halogenated hydrocarbons made the largest contribution (52.3%) to VOCs in the food processing industry. The main components of VOCs were halogenoalkanes (25.5%) and alkanes (28.8%) in rubber factories. As for graphite carbon factories, the main components of VOCs were aromatics (28.5%) and alkanes (24.1%). Compared with previous studies, the VOC emission characteristics of factories involving solvent usage in Zhengzhou are consistent with those in other cities, but the compositional information of VOCs varies across different factories, even within the same industry, due to the different production processes and raw materials used. Risk assessment showed that the concentration of VOCs emitted from solvent factories are positively correlated with ozone formation potential (OFP) and the hazard index (HI). Specifically, benzene, toluene, ethylbenzene, xylene, and other C6-C8 aromatic hydrocarbons contributed significantly to OFP and HI. The HI values were 1.18 and 2.74 in automobile manufacturing factory NO.3 and wooden furniture factory NO.5, respectively, which were higher than the limits stated by EPA regulations because of the different production processes and raw materials, and the VOCs of the factories were mainly composed of aromatics; in particular, C6-C9 benzene series contributed significantly to HI and OFP. Therefore, it is necessary to control VOCs originating from industries involving solvent usage.


Assuntos
Poluentes Atmosféricos/análise , Compostos Orgânicos Voláteis/análise , Cidades , Monitoramento Ambiental , Medição de Risco
14.
Environ Monit Assess ; 192(8): 511, 2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32661736

RESUMO

The observation and analysis of volatile organic compounds (VOCs) were conducted during January 2018 in nine prefecture-level cities of Sichuan, China, covering the period of heavily polluted weather. Air samples collected in nine prefecture-level cities were analyzed using a preconcentration method coupled with GC-MS/FID. The characteristics and ozone generation potential (OFP) of VOCs were analyzed. The relationship between air quality index (AQI) and VOCs and gross domestic product (GDP) and VOCs were also discussed, respectively. The results show that the characteristics of VOCs in cities are highly related to their industrial structure and GDP. Generally, areas with high AQI values are accompanied by high VOC concentrations. Alkanes and halocarbons were the most abundant VOCs in the atmospheric environment in the nine prefecture-level cities, accounting for 24.5~61.6% and 15.6~23.6% of total VOC concentration, respectively. The MIR method was used to analyze the OFP, and olefins contributed the most to ozone formation. Among the nine cities located in Sichuan, Dazhou was found to be the city with the highest OFP value (1191.49 µg/m3).


Assuntos
Poluentes Atmosféricos/análise , Ozônio/análise , Compostos Orgânicos Voláteis/análise , China , Cidades , Monitoramento Ambiental
15.
J Chromatogr A ; 1625: 461267, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709320

RESUMO

We describe the design and performance evaluation of a portable gas chromatograph suitable for the analysis of volatile organic and odorous compounds at trace levels. The system comprises a carbon nanotube sponge preconcentrator, an electronic pressure control (EPC) unit, a temperature-programmable column module, and a fast-response photoionization detector. A built-in tablet computer controls instrumental parameters and chromatogram display functions. The compact GC with dimensions of 35 cm (l) × 26 cm (w) × 15 cm (h) is self-contained, weighing less than 5 kg without a battery pack, and uses no auxiliary compressed gases. Our design has three main advantages over conventional portable GCs: recharging configuration of ambient air as the carrier gas using a miniature diaphragm pump, precise control of column flow by the built-in canister and EPC system, and rapid thermal desorption of the preconcentrator facilitated by intrinsic resistivity of the carbon nanotube sponge. A 30 m, 0.28 mm I.D. capillary column operated at a head pressure of 14 psi provided a peak capacity of 55 for a 10 min isothermal analysis. The temperature-programmability feature could decrease the analysis time of less than 5 min for vapor mixture of benzene, toluene, ethylbenzene, and o-xylene. More than a 100-fold increase in sensitivity by preconcentrating a sample adsorption volume of 90 mL resulted in improved detection limits of 0.13 (benzene), 0.20 (toluene), 0.23 (ethylbenzene), and 0.28 (o-xylene) ppb (v/v). Our instrument displayed good stability and reproducibility of retention times (< 0.14% RSD) and intensities (< 4.5% RSD) for continuous measurements using the preconcentrator over 10 h. Thus, continuous and on-site determinations of trace volatile organic compounds in air samples with this instrument appear feasible.


Assuntos
Poluentes Atmosféricos/análise , Cromatografia Gasosa/métodos , Sistemas Computacionais , Hidrocarbonetos Aromáticos/análise , Compostos Orgânicos Voláteis/análise , Calibragem , Gases/análise , Limite de Detecção , Nanotubos de Carbono/química , Odorantes/análise , Pressão , Reprodutibilidade dos Testes , Temperatura , Fatores de Tempo
16.
Sci Total Environ ; 741: 140148, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610229

RESUMO

People spend 80% of their time indoors exposed to poor air quality due to mold growth in humid air as well as human activities (painting, cooking, cleaning, smoking…). To better understand the impact of molds on indoor air quality, we studied the emission of microbial Volatile Organic Compounds (mVOCs) from Aspergillus niger, cultivated on malt agar extract, using a high-resolution proton transfer reaction- time of flight- mass spectrometer (PTR-TOF-MS). These emissions were studied for different cultivation time and indoor relative humidities. Our results show that the concentration of the known C4-C9 mVOCs tracers of the microbial activity (like 1-octen-3-ol, 3-methylfuran, 2-pentanone, dimethyl sulfide, dimethyl disulfide, nitromethane, 1,3-octadiene…) was the highest in the early stage of growth. However, these emissions decreased substantially after a cultivation time of 10-14 days and were highly affected by the relative humidity. In addition, the emissions of certain mVOCs were sensitive to indoor light, suggesting an impact of photochemistry on the relative amounts of indoor mVOCs. Based on this study, an estimation of the mVOC concentration for a standard living room was established at different air exchange rates and their indoor lifetimes toward hydroxyl radicals and ozone were also estimated. These findings give insights on possible mVOCs levels in moisture-damaged buildings for an early detection of microbial activity and new evidences about the effect of indoor light on their emission.


Assuntos
Poluição do Ar em Ambientes Fechados , Compostos Orgânicos Voláteis/análise , Aspergillus niger , Humanos , Volatilização
17.
Medicine (Baltimore) ; 99(27): e20937, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629696

RESUMO

The purpose of this meta-analysis was to assess the usefulness of volatile organic compounds (VOC) as a potential novel biomarker for colorectal cancer (CRC).We systematically searched PubMed, Embase, Web of Science, and Cochrane Library databases for observational studies (published before November 25th, 2019; no language restrictions) comparing the VOC analysis between patients with CRC and healthy controls. We evaluated the pooled sensitivity, specificity, diagnostic odds ratio, positive and negative likelihood ratio, as well as summary receiver operating characteristic curve and area under the curve.We identified a total of 10 observational studies that included 381 patients with CRC and 436 healthy controls. Bivariate analysis yielded a pooled sensitivity of 0.82 (95% confidence interval [CI] = 0.77-0.86), specificity of 0.79 (95% CI = 0.71-0.85), positive likelihood ratio of 3.8 (95% CI = 2.8-5.3), and negative likelihood ratio of 0.23 (95% CI = 0.17-0.30). The area under the curve was 0.87 (95% CI = 0.84-0.90). The pooled diagnostic odds ratio was 17 (95% CI = 10-28). Sensitivity analysis indicated that the pooled results were stabilized. The Deeks' funnel plot asymmetry test (P = .41) suggested no potential publication bias.Our pooled data confirmed the associations between VOC analysis and CRC, highlighting the usefulness of VOC analysis as a potential novel screening tool for CRC. However, standardization of VOC collection and analysis methods for CRC screening is required in future research.


Assuntos
Neoplasias Colorretais/diagnóstico , Compostos Orgânicos Voláteis/análise , Biomarcadores Tumorais/análise , Neoplasias Colorretais/fisiopatologia , Detecção Precoce de Câncer , Humanos , Valor Preditivo dos Testes
18.
J Breath Res ; 14(3): 030202, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32662449

RESUMO

November 2019 saw Cambridge, UK play host to the second Breath Biopsy Conference, a community-focused event aimed at sharing and supporting advancements in the collection and analysis of volatile organic compounds in exhaled breath. The event expanded upon the previous year's format, spanning two days and concluding with an expert panel discussion. Presentations covered detection, monitoring and precision medicine studies examining diseases including asthma, cirrhosis, cancer and tuberculosis. The meeting attracted representatives from diverse backgrounds, such as metabolomics, artificial intelligence, clinical research and chemical analysis. This meeting report offers an overview of what was presented and discussed during the conference.


Assuntos
Biomarcadores/análise , Testes Respiratórios/métodos , Expiração , Inteligência Artificial , Biópsia , Humanos , Compostos Orgânicos Voláteis/análise
19.
Food Chem ; 333: 127450, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32663749

RESUMO

The aged wine spirit is a beverage with great aromatic complexity. Their volatile compounds with odorant power coming from the distillate and from the wood used in its ageing, and the interactions that take place in the process, enhanced by oxygen, all contribute to this complexity. Due to time and cost inherent of ageing wine spirits in wooden barrels, research has sought to develop more sustainable alternatives to do it. In this context, the present study compares, the effect of traditional (wooden barrel) and alternative system (stainless steel tank with dipped staves and micro-oxygenation), on the odorant and sensory profile of a wine spirit, using Limousin oak and chestnut wood, after 12 months of ageing. The results suggest that the ageing process is accelerated by the alternative ageing technology and the chestnut wood, and the corresponding wine spirits presented characteristics of greater sensory evolution and strong wood compounds extraction.


Assuntos
Indústria de Processamento de Alimentos/métodos , Odorantes , Vinho , Madeira , Adulto , Aesculus , Idoso , Feminino , Indústria de Processamento de Alimentos/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Odorantes/análise , Oxigênio/química , Quercus , Aço Inoxidável , Fatores de Tempo , Compostos Orgânicos Voláteis/análise , Vinho/análise
20.
Food Chem ; 332: 127385, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32623125

RESUMO

A promising way of processing Baltic herring, Clupea harengus membras, is turning the fish into boneless mince. However, Baltic herring is prone to lipid oxidation, which possesses a challenge for industrial applications. The aim of this work was to study the efficacy of press cakes from Finnish berries and a supercritical CO2 plant extract to limit lipid oxidation during frozen storage of Baltic herring mince and to determine the impact of these additions on consumer acceptance in a fish product. Peroxide value, formation of volatile oxidation products and loss of polyunsaturated fatty acids showed that the tested natural additives decreased oxidation to a greater or similar extent as conventional antioxidants during 10-month storage. While potential of berry press cakes and plant extracts as "green label antioxidants" was shown, consumer study indicated need for further research to reach both optimal antioxidative efficacy and sensory properties.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Produtos Pesqueiros/análise , Extratos Vegetais/química , Animais , Antioxidantes/química , Dióxido de Carbono/química , Ácidos Docosa-Hexaenoicos/análise , Ácido Eicosapentaenoico/análise , Peixes , Congelamento , Lipídeos/análise , Fenóis/análise , Compostos Orgânicos Voláteis/análise
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