keyword
MENU ▼
Read by QxMD icon Read
search

Flame study

keyword
https://www.readbyqxmd.com/read/28738652/volatile-composition-of-merlot-red-wine-and-its-contribution-to-the-aroma-optimization-and-validation-of-analytical-method
#1
Stefany Grützmann Arcari, Vinicius Caliari, Marla Sganzerla, Helena Teixeira Godoy
A methodology for the determination of volatile compounds in red wine using headspace solid phase microextraction (HS-SPME) combined with gas chromatography-ion trap/ mass spectrometry (GC-IT/MS) and flame ionization detector (GC -FID) was developed, validated and applied to a sample of Brazilian red wine. The optimization strategy was conducted using the Plackett-Burman design for variable selection and central composite rotational design (CCRD). The response surface methodology showed that the performance of the extraction of the volatile compounds using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber is improved with no sample dilution, the addition of 30% NaCl, applying an extraction temperature of 56°C and extraction time of 55min...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738556/development-of-a-new-sample-preparation-method-based-on-liquid-liquid-liquid-extraction-combined-with-dispersive-liquid-liquid-microextraction-and-its-application-on-unfiltered-samples-containing-high-content-of-solids
#2
Mir Ali Farajzadeh, Maryam Abbaspour
A new sample preparation method based on liquid-liquid-liquid extraction combined with dispersive liquid-liquid microextraction followed by gas chromatography-flame ionization detection has been reported for the extraction/preconcentration and determination of trace levels of twelve pesticide residues from different samples with high content of solids without filtration. This method consists of a three-phase system including an aqueous phase (sample solution), acetonitrile, and hexane. The extraction mechanism is based on different affinities of the substances from the sample matrices towards each of the involved phase, which provides a high selectivity to the process...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28735244/legacy-and-novel-brominated-flame-retardants-in-interior-car-dust%C3%A2-%C3%A2-implications-for-human-exposure
#3
Athanasios Besis, Christina Christia, Giulia Poma, Adrian Covaci, Constantini Samara
Brominated flame retardants (BFRs) are organobromine compounds with an inhibitory effect on combustion chemistry tending to reduce the flammability of products. Concerns about health effects and environmental threats have led to phase-out or restrictions in the use of Penta-, Octa- and Deca-BDE technical formulations, increasing the demand for Novel BFRs (NBFRs) as replacements for the banned formulations. This study examined the occurrence of legacy and NBFRs in the dust from the interior of private cars in Thessaloniki, Greece, aged from 1 to 19 years with variable origin and characteristics...
July 20, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28734253/polybrominated-diphenyl-ether-flame-retardant-concentrations-in-faeces-from-young-children-in-queensland-australia-and-associations-with-environmental-and-behavioural-factors
#4
Karin English, Yiqin Chen, Leisa-Maree Toms, Paul Jagals, Robert S Ware, Jochen F Mueller, Peter D Sly
The aim of our study was to investigate children's exposure to the flame retardants polybrominated diphenyl ethers (PBDEs) by analysing faecal content, a non-invasive matrix, as well as responses to an exposure-assessment questionnaire. A convenience sample of 61 parents with children (aged >3 months to <2 years) completed an online pre-tested questionnaire and provided faecal samples for analysis by high resolution gas chromatography/mass spectrometry. BDE-209 was the dominant congener in faecal samples adjusted to 8...
July 19, 2017: Environmental Research
https://www.readbyqxmd.com/read/28733937/sequential-extraction-as-novel-approach-to-compare-12-medicinal-plants-from-kenya-regarding-their-potential-to-release-chromium-manganese-copper-and-zinc
#5
R Mogwasi, S Zor, D K Kariuki, M Z Getenga, V Nischwitz
This study is focusing on a novel approach to screen a large number of medicinal plants from Kenya regarding their contents and availability of selected metals potentially relevant for treatment of diabetes patients. For this purpose, total levels of zinc, chromium, manganese, and copper were determined by flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry as well as BCR sequential extraction to fractionate the elemental species in anti-diabetic medicinal plants collected from five natural locations in two sub counties in Nyamira County, Kenya...
July 21, 2017: Biological Trace Element Research
https://www.readbyqxmd.com/read/28732951/application-of-ultrasonically-modified-cloud-point-extraction-method-for-simultaneous-enrichment-of-cadmium-and-lead-in-sera-of-different-types-of-gallstone-patients
#6
Mustafa Khan, Tasneem Gul Kazi, Hasan Imran Afridi, Muhammad Bilal, Asma Akhtar, Naeem Ullah, Sabir Khan, Sehrish Talpur
A novel and greener ultrasonically assisted/modified cloud point extraction procedure for the simultaneous preconcentration of lead and cadmium in serum samples of different types of gallstone patients was developed. The chelates of the under study metals, formerly formed with 8-hydroxyquinoline, were extracted in the micelles of a nonionic surfactant prior to analysis by flame atomic absorption spectrometer (FAAS). After the arrival of the cloud point, the critical micellar mass produced was homogenously dispersed in the aqueous phase with the help of ultrasound energy...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28732339/aryl-and-alkyl-phosphorus-containing-flame-retardants-induced-mitochondrial-impairment-and-cell-death-in-chinese-hamster-ovary-cho-k1-cells
#7
Chao Huang, Na Li, Shengwu Yuan, Xiaoya Ji, Mei Ma, Kaifeng Rao, Zijian Wang
Phosphorus-containing flame retardants (PFRs) are increasingly in demand worldwide as replacements for brominated flame retardants (BFRs), but insufficient available toxicological information on PFRs makes assessing their health risks challenging. Mitochondria are important targets of various environmental pollutants, and mitochondrial dysfunction may lead to many common diseases. In the present study, mitochondria impairment-related endpoints were measured by a high content screening (HCS) assay for 11 selected non-halogen PFRs in Chinese hamster ovary (CHO-k1) cells...
July 18, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28732330/legacy-persistent-organic-pollutants-including-pbdes-in-the-trophic-web-of-the-ross-sea-antarctica
#8
Simonetta Corsolini, Nicoletta Ademollo, Tania Martellini, Demetrio Randazzo, Marino Vacchi, Alessandra Cincinelli
The ecological features of the Ross Sea trophic web are peculiar and different from other polar food webs, with respect to the use of habitat and species interactions; due to its ecosystem integrity, it is the world's largest Marine Protected Area, established in 2016. Polar organisms are reported to bioaccumulate lipophilic contaminant, viz persistent organic pollutants (POPs). Legacy POPs and flame retardants (polybrominated diphenyl ethers, PBDEs) were studied in key species of the Ross Sea (Euphausia superba, Pleuragramma antarctica) and their predators (Dissostichus mawsoni, Pygoscelis adeliae, Aptenodytes forsteri, Catharacta maccormicki, Leptonychotes weddellii)...
July 12, 2017: Chemosphere
https://www.readbyqxmd.com/read/28725084/development-of-a-single-drop-microextraction-with-derivatization-procedure-for-analysis-of-volatile-fatty-acids-in-water-samples
#9
Grażyna Wejnerowska
A single-drop microextraction (SDME) was developed for the analysis of volatile fatty acids (VFAs) (C2-C7) in water by gas chromatography (GC) with flame ionization detection. The significant parameters affecting the SDME performance such as selection of microextraction solvent, extraction time, stirring rate, sample pH and temperature, and ionic strength were studied and optimized. To lower limits of detection, derivatization of VFAs by N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) was performed...
2017: Chromatographia
https://www.readbyqxmd.com/read/28718246/effect-of-cobalt-chromium-alloy-re-use-in-dentistry-on-its-castability-value
#10
Yogendra Imran, Muhammad Raza, Muhammad Sartaj Khan, Yousaf Hayat
BACKGROUND: Re-use of dental casting alloy is a routine practice, which is carried out with the motive to conserve resources. There have been studies on the re-use of alloys but a controversy exists as to the proportioning ratio of fresh to used alloy and the number of time an alloy can be recast. The objective of the study was to measure the effect of addition of 50% by weight used alloy to the fresh Cobalt-Chromium alloy on the castability. METHODS: In the present in-vitro experimental study A total of 20 specimens were cast by flame centrifuge, using modified Whitlock's method...
April 2017: Journal of Ayub Medical College, Abbottabad: JAMC
https://www.readbyqxmd.com/read/28715756/the-occurrence-and-spatial-temporal-distribution-of-tetrabromobisphenol-a-in-the-coastal-intertidal-zone-of-qingdao-in-china-with-a-focus-on-toxicity-assessment-by-biological-monitoring
#11
Wen-Jing Gong, Li-Yan Zhu, Tian-Tian Jiang, Cui Han
Tetrabromobisphenol A (TBBPA) is a widely used flame retardant that has increasingly been found as contaminant in aquatic environments. The main goal of this study was to evaluate the pollution level of TBBPA at six locations around Qingdao and assess its biotoxicity through a two-generation toxicity study looking at a copepod species. In the chemical monitoring, the concentration of TBBPA in seawater samples ranged from nd to 1.8 μg/L. Next, the biological indicator monitoring used 1.8 μg/L as the middle exposure concentration to perform quantitative evaluations of the influence of TBBPA on the demographic traits of Pseudodiaptomus inopinus...
July 10, 2017: Chemosphere
https://www.readbyqxmd.com/read/28715015/ultralight-highly-thermally-insulating-and-fire-resistant-aerogel-by-encapsulating-cellulose-nanofibers-with-two-dimensional-mos2
#12
Lei Yang, Alolika Mukhopadhyay, Yucong Jiao, Qiang Yong, Liao Chen, Yingjie Xing, Jonathan Hamel, Hongli Zhu
Thermally insulating materials, made from earth-abundant and sustainable resources, are highly desirable in the sustainable construction of energy efficient buildings. Cellulose from wood has long been recognized for these characteristics. However, cellulose can be a flammability hazard, and for construction this has been addressed via chemical treatment such as that with halogen and/or phosphorus, which leads to further environmental concerns. Fortunately, the structure of cellulose lends itself well to chemical modification, giving great potential to explore interaction with other compounds...
July 17, 2017: Nanoscale
https://www.readbyqxmd.com/read/28712647/perinatal-exposure-to-2-2-4-4-tetrabromodiphenyl-ether-induces-testicular-toxicity-in-adult-rats
#13
Ahmed Khalil, Mikhail Parker, Sarah E Brown, Sebnem E Cevik, Lian W Guo, Jake Jensen, Alexandra Olmsted, Daneal Portman, Haotian Wu, Alexander Suvorov
Since 1965, polybrominated diphenyl ethers (PBDEs) have been used internationally as flame-retardant additives. PBDEs were recently withdrawn from commerce in North America and Europe due to their environmental persistence, bioaccumulative properties and endocrine-disrupting effects. Generations exposed perinatally to the highest environmental doses of PBDE account for one-fifth of the total United States population. While, toxicity of PBDE for the male reproductive system has been demonstrated in several human and animal studies, the long-lasting effects of perinatal exposures on male reproduction are still poorly understood...
July 13, 2017: Toxicology
https://www.readbyqxmd.com/read/28711770/multigenerational-effects-evaluation-of-the-flame-retardant-tris-2-butoxyethyl-phosphate-tboep-using-daphnia-magna
#14
Maeva Giraudo, Maxime Dubé, Mélanie Lépine, Pierre Gagnon, Mélanie Douville, Magali Houde
Tris(2-butoxyethyl) phosphate (TBOEP) is an organophosphate ester used as substitute following the phase-out of brominated flamed retardants. Because of its high production volume and its use in a broad range of applications, this chemical is now frequently detected in the environment and biota. However, limited information is available on the long-term effects of TBOEP in aquatic organisms. In this study, Daphnia magna were exposed over three 21d generations to an environmentally relevant concentration of TBOEP (10μg/L) and effects were evaluated at the gene transcription, protein, and life-history (i...
July 8, 2017: Aquatic Toxicology
https://www.readbyqxmd.com/read/28709211/combustion-instability-mitigation-by-magnetic-fields
#15
Agnes Jocher, Heinz Pitsch, Thomas Gomez, Jérôme Bonnety, Guillaume Legros
The present interdisciplinary study combines electromagnetics and combustion to unveil an original and basic experiment displaying a spontaneous flame instability that is mitigated as the non-premixed sooting flame experiences a magnetic perturbation. This magnetic instability mitigation is reproduced by direct numerical simulations to be further elucidated by a flow stability analysis. A key role in the stabilization process is attributed to the momentum and thermochemistry coupling that the magnetic force, acting mainly on paramagnetic oxygen, contributes to sustain...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28709054/probing-the-relationship-between-external-and-internal-human-exposure-of-organophosphate-flame-retardants-using-pharmacokinetic-modelling
#16
Thuy T Bui, Fuchao Xu, Nele Van den Eede, Anna Palm Cousins, Adrian Covaci, Ian T Cousins
Human external exposure (i.e. intake) of organophosphate flame retardants (PFRs) has recently been quantified, but no link has yet been established between external and internal exposure. In this study, we used a pharmacokinetic (PK) model to probe the relationship between external and internal exposure data for three PFRs (EHDPHP, TNBP and TPHP) available for a Norwegian cohort of 61 individuals from 61 different households. Using current literature on metabolism of PFRs, we predicted the metabolite serum/urine concentrations and compared it to measured data from the study population...
July 11, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28709039/agricultural-management-of-an-oxisol-affects-accumulation-of-heavy-metals
#17
Guilherme Deomedesse Minari, David Luciano Rosalen, Mara Cristina Pessôa da Cruz, Wanderley José de Melo, Lucia Maria Carareto Alves, Luciana Maria Saran
Soil contamination may result from the inadequate disposal of substances with polluting potential or prolonged agricultural use. Therefore, cadmium (Cd), chromium (Cr) and nickel (Ni) concentrations were assessed in a Eutroferric Red Oxisol under a no-tillage farming system with mineral fertilizer applications, a conventional tillage system with mineral fertilizer application and a conventional tillage system with sewage sludge application in an area used for agriculture for more than 80 years. We evaluated the spatial distributions of these elements in the experimental area and the effect of the different management practices on the soil retention of these metals...
July 3, 2017: Chemosphere
https://www.readbyqxmd.com/read/28704964/myrcia-splendens-sw-dc-syn-m-fallax-rich-dc-myrtaceae-essential-oil-from-amazonian-ecuador-a-chemical-characterization-and-bioactivity-profile
#18
Laura Scalvenzi, Alessandro Grandini, Antonella Spagnoletti, Massimo Tacchini, David Neill, José Luis Ballesteros, Gianni Sacchetti, Alessandra Guerrini
In this study, we performed the chemical characterization of Myrcia splendens (Sw.) DC. (Myrtaceae) essential oil from Amazonian Ecuador and the assessment of its bioactivity in terms of cytotoxic, antibacterial, and antioxidant activity as starting point for possible applicative uses. M. splendens essential oil, obtained by hydro-distillation, was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID): the major components were found to be trans-nerolidol (67...
July 12, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28704803/occurrence-and-fate-of-organophosphate-ester-flame-retardants-and-plasticizers-in-indoor-air-and-dust-of-nepal-implication-for-human-exposure
#19
Ishwar Chandra Yadav, Ningombam Linthoingambi Devi, Guangcai Zhong, Jun Li, Gan Zhang, Adrian Covaci
The present study was carried out in Nepal, a landlocked country located between world's two most populous countries i.e. India and China. In this study, the occurrence, profiles, spatial distributions and fate of eight organophosphate ester flame retardants (OPFRs) were investigated in indoor air and house dust. Overall, the concentrations of ∑OPFR were in the range of 153-12100 ng/g (median732 ng/g) and 0.32-64 ng/m(3) (median 5.2 ng/m(3)) in house dust and indoor air, respectively. The sources of high OPFR in the indoor environment could be from locally used wide variety of consumer products and building materials in Nepalese houses...
July 10, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28702614/on-the-role-of-resonantly-stabilized-radicals-in-polycyclic-aromatic-hydrocarbon-pah-formation-pyrene-and-fluoranthene-formation-from-benzyl-indenyl-addition
#20
Sourab Sinha, Ramees K Rahman, Abhijeet Raj
Resonantly stabilized radicals, such as propargyl, cyclopentadienyl, benzyl, and indenyl, play a vital role in the formation and growth of polycyclic aromatic hydrocarbons (PAHs) that are soot precursors in engines and flames. Pyrene is considered to be an important PAH, as it is thought to nucleate soot particles, but its formation pathways are not well known. This paper presents a reaction mechanism for the formation of four-ring aromatics, pyrene and fluoranthene, through the combination of benzyl and indenyl radicals...
July 13, 2017: Physical Chemistry Chemical Physics: PCCP
keyword
keyword
69154
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"