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Volatile organic compound analysis

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https://www.readbyqxmd.com/read/28649963/the-effect-of-growth-medium-on-i-escherichia-coli-i-pathway-mirrored-into-gc-ms-profiles
#1
Ileana Andreea Ratiu, Tomasz Ligor, Victor Bocos-Bintintan, Hossam Al-Suod, Tomasz Kowalkowski, Katarzyna Rafińska, Boguslaw Buszewski
Escherichia coli (E. coli) is a gram-negative coliform bacterium that is commonly found in the lower intestine of warm-blooded organisms. Most of the strains are harmless, but some serotypes are pathogenic, meaning they can cause illness, either diarrhea or illness outside of the intestinal tract. The aim of this work was to assess which components are generated in case of E. coli target analysis needed. In this purpose our study intends to emphasize the importance of the cultivability and to prove the crucial role of growth media used in bacteria growing...
June 26, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28640741/an-endophytic-fusarium-sp-isolated-from-monarda-citriodora-produces-the-industrially-important-plant-like-volatile-organic-compound-hexanal
#2
Meenu Katoch, Kushal Bindu, Shipra Phull, M K Verma
An endophytic fungus, MC_25L, has been isolated from the leaves of MonardacitriodoraCerv. ex Lag., a medicinal and aromatic herb from the northwestern Himalayas. It produces a fruity fragrance while growing on potato dextrose agar, suggesting that it is producing volatile organic compounds (VOCs). The endophyte inhibited the growth of plant pathogens such asSclerotiniasp. and Aspergillusflavus by virtue of VOCs. Identification of MC_25L based on morphological and microscopic features, as well as ITS-based rDNA sequence analysis, revealed that it is a Fusariumsp...
June 22, 2017: Microbiology
https://www.readbyqxmd.com/read/28635673/toxicity-of-naphthalene-and-benzene-on-tribollium-castaneum-herbst
#3
Nerlis Pajaro-Castro, Karina Caballero-Gallardo, Jesus Olivero-Verbel
Naphthalene and benzene are widely-used volatile organic compounds. The aim of this research was to examine the toxicological effects of naphthalene and benzene against Tribolium castaneum as an animal model. Adult insects were exposed to these aromatic compounds to assess mortality after 4-48 h of exposure. The lethal concentration 50 (LC50) for naphthalene, naphthalin, and benzene were 63.6 µL/L, 20.0 µL/L, and 115.9 µL/L in air, respectively. Real-time polymerase chain reaction (PCR) analysis revealed expression changes in genes related to oxidative stress and metabolism [Glutathione S-Transferase (Gst), and Cytochrome P450 6BQ8 (Cyp6bq8)]; reproduction and metamorphosis [Hormone receptor in 39-like protein (Hr39), Ecdysone receptor: (Ecr), and Chitin synthase 2 (Chs2)]; and neurotransmission [Histamine-gated chloride channel 2 (Hiscl2)] in insects exposed for 4 h to 70...
June 21, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28635619/on-the-importance-of-accurate-quantification-of-individual-volatile-metabolites-in-exhaled-breath
#4
David Smith, Patrik Spanel
It is argued that shortcomings of certain approaches to breath analysis research based on superficial interpretation of non-quantitative data are inadvertently inhibiting the progression of non-invasive breath analysis into clinical practice. The objective of this perspective is to suggest more clinically profitable approaches to breath research. Thus, following a discourse on the challenges and expectations in breath research, a brief indication is given of the analytical techniques currently used for the analysis of very humid exhaled breath...
June 21, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28633145/urinary-volatile-organic-compounds-as-potential-biomarkers-in-idiopathic-membranous-nephropathy
#5
Mingao Wang, Rujuan Xie, Xibei Jia, Ruichan Liu
OBJECTIVE: To detect urinary volatile organic compounds (VOCs) in patients with idiopathic membranous nephropathy (iMN) and normal controls, and whether or not the urinary VOCs can act as biomarkers for diagnosis of iMN independent of renal biopsy. MATERIALS AND METHODS: Gas chromatography/mass spectrometry (GC/MS) was used to assess the urine collected from 63 iMN patients and 15 normal controls. The statistical methods of principal component analysis (PCA) and partial least squares discriminant analysis (PLSDA) were performed to process the final data in CDF format which were converted from GC/MS data...
June 19, 2017: Medical Principles and Practice: International Journal of the Kuwait University, Health Science Centre
https://www.readbyqxmd.com/read/28631877/identification-of-chemical-components-in-baidianling-capsule-based-on-gc-ms-and-hplc-combined-with-fourier-transform-ion-cyclotron-resonance-mass-spectrometry
#6
Wenying Wu, Yu Chen, Binjie Wang, Xiaoyang Sun, Ping Guo, Xiaohui Chen
Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography with mass spectrometry in combination with retention indices and high-performance liquid chromatography combined with Fourier transform-ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkyne, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furan, pyrrole, acid amide, heterocycle and oxide were detected from Baidianling Capsule by gas chromatography with mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index...
June 20, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28628730/comparative-study-on-ambient-ionization-methods-for-direct-analysis-of-navel-orange-tissues-by-mass-spectrometry
#7
H Zhang, A Bibi, H Lu, J Han, H Chen
It is of sustainable interest to improve the sensitivity and selectivity of the ionization process, especially for direct analysis of complex samples without matrix separation. Herein, four ambient ionization methods including desorption atmospheric pressure chemical ionization (DAPCI), heat-assisted desorption atmospheric pressure chemical ionization (heat-assisted DAPCI), microwave plasma torch (MPT), and internal extractive electrospray ionization (iEESI) were employed for comparative analysis of the navel orange tissue samples by mass spectrometry...
June 19, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28626990/exhaled-breath-profiles-in-the-monitoring-of-loss-of-control-and-clinical-recovery-in-asthma
#8
Paul Brinkman, Marianne A van de Pol, Marije G Gerritsen, Lieuwe D Bos, Tamara Dekker, Barbara S Smids, Anirban Sinha, Christof J Majoor, Marlous M Sneeboer, Hugo H Knobel, Teunis J Vink, Frans H de Jongh, René Lutter, Peter J Sterk, Niki Fens
BACKGROUND: Asthma is a chronic inflammatory airway disease, associated with episodes of exacerbations. Therapy with inhaled corticosteroids (ICS) targets airway inflammation, which aims to maintain and restore asthma control. Clinical features are only modestly associated with airways inflammation. Therefore, we hypothesized that exhaled volatile metabolites identify longitudinal changes between clinically stable episodes and loss of asthma control. OBJECTIVES: To determine whether exhaled volatile organic compounds (VOCs) as measured by gas-chromatography / mass-spectrometry (GC/MS) and electronic nose (eNose) technology discriminate between clinically stable and unstable episodes of asthma...
June 19, 2017: Clinical and Experimental Allergy: Journal of the British Society for Allergy and Clinical Immunology
https://www.readbyqxmd.com/read/28619588/a-system-map-for-the-ionic-liquid-stationary-phase-1-12-di-tripropylphosphonium-dodecane-bis-trifluoromethylsulfonyl-imide-trifluoromethanesulfonate-for-gas-chromatography
#9
Nicole Lenca, Colin F Poole
The solvation parameter model is used to prepare a system map for the retention of volatile organic compounds on the ionic liquid stationary phase 1,12-di(tripropylphosphonium)dodecane bis(trifluoromethylsulfonyl)imide trifluoromethanesulfonate (SLB-IL61) over the temperature range 80-260°C. Retention is governed by dispersion, dipole-type and hydrogen-bonding interactions each with its own temperature dependence. The exchange of a bis(trifluoromethylsulfonyl)imide anion in SLB-IL60 for a trifluromethanesulfonate anion (SLB-IL61) results in a change in selectivity indicated by an increase in the hydrogen-bond basicity and a decrease in hydrogen-bond acidity of the stationary phase without change in either the cohesion or dipolarity/polarizability of the stationary phases...
June 8, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28616692/a-minimally-invasive-method-for-profiling-volatile-organic-compounds-within-postmortem-internal-gas-reservoirs
#10
Katelynn A Perrault, Pierre-Hugues Stefanuto, Lena M Dubois, Vincent Varlet, Silke Grabherr, Jean-François Focant
In forensic casework, non-invasive and minimally-invasive methods for postmortem examinations are extremely valuable. Whole body postmortem computed tomography (PMCT) is often used to provide visualization of the internal characteristics of a body prior to more invasive procedures and has also been used to locate gas reservoirs inside the body to assist in determining cause of death. Preliminary studies have demonstrated that exploiting the volatile organic compounds (VOCs) located in these gas reservoirs by comprehensive two-dimensional gas chromatography-high-resolution time-of-flight mass spectrometry (GC×GC-HRTOF-MS) may assist in providing information regarding the postmortem interval...
June 15, 2017: International Journal of Legal Medicine
https://www.readbyqxmd.com/read/28615048/integrated-metabolome-and-transcriptome-analysis-of-magnolia-champaca-identifies-biosynthetic-pathways-for-floral-volatile-organic-compounds
#11
Savitha Dhandapani, Jingjing Jin, Vishweshwaran Sridhar, Rajani Sarojam, Nam-Hai Chua, In-Cheol Jang
BACKGROUND: Magnolia champaca, commonly known as champak is a well-known tree due to its highly fragrant flowers. Champak floral scent is attributed to a complex mix of volatile organic compounds (VOCs). These aromatic flowers are widely used in flavors and fragrances industry. Despite its commercial importance, the VOC biosynthesis pathways in these flowers are largely unknown. Here, we combine metabolite and RNA sequencing (RNA-seq) analyses of fully opened champak flowers to discover the active VOC biosynthesis pathways as well as floral scent-related genes...
June 14, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28614750/2d-cos-of-in-situ-%C3%AE-raman-and-in-situ-ir-spectra-for-structure-evolution-characterisation-of-nep-deposited-cobalt-oxide-catalyst-during-n-nonane-combustion
#12
Damian K Chlebda, Przemysław J Jodłowski, Roman J Jędrzejczyk, Joanna Łojewska
New catalytic systems are still in development to meet the challenge of regulations concerning the emission of volatile organic compounds (VOCs). This is because such compounds have a significant impact on air quality and some of them are toxic to the environment and human beings. The catalytic combustion process of VOCs over non-noble metal catalysts is of great interest to researchers. The high conversion parameters and cost effective preparation makes them a valuable alternative to monoliths and noble metal catalysts...
June 6, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28608392/volatile-organic-compounds-analysis-by-pulsed-glow-discharge-time-of-flight-mass-spectrometry-as-a-structural-elucidation-tool
#13
M Bouza, J Fandino, N Bordel, R Pereiro, A Sanz-Medel
Pulsed glow discharge (PGD) coupled to time of flight mass spectrometry (TOFMS) has been investigated for volatile organic compounds (VOCs) identification and determination. Optimization of PGD operational conditions (chamber design, applied power, pressure and duty cycle) was performed using acetone and benzene as model compounds. During the different optimizations, molecular, fragment and elemental information were obtained when characteristic GD pulse regions were measured. An exploratory study for several VOCs (lineal hydrocarbons, oxygen-containing compounds and aromatic compounds) revealed the capability of the PGD to provide crucial information to elucidate structures (fragments), molecular ions or even proton affinity nature of the molecules; this last information is a consequence of the enriched proton environment generated along the afterglow region for the ionization chamber used...
June 12, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28601915/volatile-organic-compounds-in-the-breath-of-oral-candidiasis-patients-a-pilot-study
#14
Moritz Hertel, Eyke Schuette, Isabell Kastner, Stefan Hartwig, Andrea Maria Schmidt-Westhausen, Robert Preissner, Sebastian Paris, Saskia Preissner
OBJECTIVES: The aim of the study was to investigate whether specific volatile organic compounds (VOCs) can be detected in oral candidiasis patients using breath analysis in order to develop a point-of-care diagnostic tool. PATIENTS/METHODS: Breath samples of 10 diseased patients and 10 subjects carrying no Candida spp. were analyzed using gas chromatography and mass spectrometry. In infected patients, breath tests were performed before and after antifungal therapy...
June 10, 2017: Clinical Oral Investigations
https://www.readbyqxmd.com/read/28597921/feasibility-of-canine-detection-of-mass-storage-devices-a-study-of-volatile-organic-compounds-emanating-from-electronic-devices-using-solid-phase-microextraction
#15
Lauryn E DeGreeff, Michelle Cerreta, Mark Rispoli
Detection of canines are well-known to be valuable in the location of contraband, such as explosives or narcotics. More recently, canines have been trained and utilized in the detection of concealed mass storage devices that might contain evidence of illegal activity such as child pornography. To lay the analytical foundation for this detection work, research was carried out to determine the volatile organic compounds associated with mass storage devices (MSD) that could be used by trained canines for detection...
June 9, 2017: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/28588235/parasitic-nematode-meloidogyne-incognita-interactions-with-different-capsicum-annum-cultivars-reveal-the-chemical-constituents-modulating-root-herbivory
#16
Ruth Kihika, Lucy K Murungi, Danny Coyne, Margaret Ng'ang'a, Ahmed Hassanali, Peter E A Teal, Baldwyn Torto
Plant volatile signatures are often used as cues by herbivores to locate their preferred hosts. Here, we report on the volatile organic compounds used by the subterranean root-knot nematode (RKN) Meloidogyne incognita for host location. We compared responses of infective second stage juveniles (J2s) to root volatiles of three cultivars and one accession of the solanaceous plant, Capsicum annum against moist sand in dual choice assays. J2s were more attracted to the three cultivars than to the accession, relative to controls...
June 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28587778/advanced-method-optimization-for-volatile-aroma-profiling-of-beer-using-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry
#17
Pierre-Hugues Stefanuto, Katelynn A Perrault, Lena M Dubois, Benjamin L'Homme, Catherine Allen, Caitriona Loughnane, Nobuo Ochiai, Jean-François Focant
The complex mixture of volatile organic compounds (VOCs) present in the headspace of Trappist and craft beers was studied to illustrate the efficiency of thermal desorption (TD) comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) for highlighting subtle differences between highly complex mixtures of VOCs. Headspace solid-phase microextraction (HS-SPME), multiple (and classical) stir bar sorptive extraction (mSBSE), static headspace (SHS), and dynamic headspace (DHS) were compared for the extraction of a set of 21 representative flavor compounds of beer aroma...
June 1, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28587077/floral-scent-chemistry-of-luculia-yunnanensis-rubiaceae-a-species-endemic-to-china-with-sweetly-fragrant-flowers
#18
Yuying Li, Youming Wan, Zhenghai Sun, Taiqiang Li, Xiongfang Liu, Hong Ma, Xiuxian Liu, Rui He, Yan Ma, Zhenghong Li
Luculia plants are famed ornamentals with sweetly fragrant flowers. Luculia yunnanensis Hu is an endemic plant from Yunnan Province, China. Headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to identify the volatile organic compounds (VOCs) of the different flower development stages of L. yunnanensis for the evaluation of floral volatile polymorphism. The results showed that a total of 40 compounds were identified at four different stages. The main aroma-active compounds were 3-carene, α-cubebene, α-copaene, δ-cadinene, and isoledene...
May 25, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28585324/identification-of-major-loci-and-genomic-regions-controlling-acid-and-volatile-content-in-tomato-fruit-implications-for-flavor-improvement
#19
Guillaume Bauchet, Stéphane Grenier, Nicolas Samson, Vincent Segura, Aniko Kende, Jules Beekwilder, Katarina Cankar, Jean-Luc Gallois, Justine Gricourt, Julien Bonnet, Charles Baxter, Laurent Grivet, Mathilde Causse
Plant metabolites are important to world food security due to their roles in crop yield and nutritional quality. Here we report the metabolic profile of 300 tomato accessions (Solanum lycopersicum and related wild species) by quantifying 60 primary and secondary metabolites, including volatile organic compounds, over a period of 2 yr. Metabolite content and genetic inheritance of metabolites varied broadly, both within and between different genetic groups. Using genotype information gained from 10 000 single nucleotide polymorphism markers, we performed a metabolite genome-wide association mapping (GWAS) study...
June 6, 2017: New Phytologist
https://www.readbyqxmd.com/read/28576361/multiple-microbial-cell-free-extracts-improve-the-microbiological-biochemical-and-sensory-features-of-ewes-milk-cheese
#20
Maria Calasso, Leonardo Mancini, Maria De Angelis, Amalia Conte, Cristina Costa, Matteo Alessandro Del Nobile, Marco Gobbetti
This study used cell-free enzyme (CFE) extracts from Lactobacillus casei, Hafnia alvei, Debaryomyces hansenii and Saccharomyces cerevisiae to condition or accelerate Pecorino-type cheese ripening. Compositional, microbiological, and biochemical analyses were performed, and volatile and sensory profiles were obtained. Lactobacilli and cocci increased during ripening, especially in cheeses containing CFE from L. casei, H. alvei and D. hansenii (LHD-C) and L. casei, H. alvei and S. cerevisiae (LHS-C). Compared to control cheese (CC), several enzymatic activities were higher (P < 0...
September 2017: Food Microbiology
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