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https://www.readbyqxmd.com/read/29140076/direct-analysis-of-lignin-phenols-in-freshwater-dissolved-organic-matter
#1
Hendrik Reuter, Julia Gensel, Marcus Elvert, Dominik Zak
A novel approach for the analysis of dissolved lignin in freshwaters is presented. Lignin concentrations in natural waters are low and a lignin extraction is usually required to obtain sufficient sample for analysis. In this method, extraction and dry down of the dissolved lignin are omitted and alkaline CuO oxidation is directly performed using 15 mL water sample in a microwave digestion system, thus reducing the required amount of sample and its preparation time considerably. Low procedural blank values are obtained by solid phase extraction (SPE) of the oxidized lignin phenols on HLB sorbents...
November 15, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29138882/further-improvements-in-pesticide-residue-analysis-in-food-by-applying-gas-chromatography-triple-quadrupole-mass-spectrometry-gc-qqq-ms-ms-technologies
#2
Elena Hakme, Ana Lozano, Samanta Uclés, Amadeo R Fernández-Alba
Nowadays, the control of pesticide residues in food is well established. The capacity of triple quadrupole technology to satisfy the current food regulations has been demonstrated. However, the permanent high demand of consumers for more sensitive and faster testing is driving the development of improved analytical methodologies that increase the performances of sensitivity and robustness and reduce the analysis time. In this work, the feasibility of decreasing the run time to 12.4 min by modifying the oven temperature program, for a multiresidue method covering 203 pesticides, was evaluated...
November 14, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29137184/cell-type-specific-metabolic-flux-analysis-a-challenge-for-metabolic-phenotyping-and-a-potential-solution-in-plants
#3
Merja T Rossi, Monika Kalde, Chaiyakorn Srisakvarakul, Nicholas J Kruger, R George Ratcliffe
Stable isotope labelling experiments are used routinely in metabolic flux analysis (MFA) to determine the metabolic phenotype of cells and tissues. A complication arises in multicellular systems because single cell measurements of transcriptomes, proteomes and metabolomes in multicellular organisms suggest that the metabolic phenotype will differ between cell types. In silico analysis of simulated metabolite isotopomer datasets shows that cellular heterogeneity confounds conventional MFA because labelling data averaged over multiple cell types does not necessarily yield averaged flux values...
November 13, 2017: Metabolites
https://www.readbyqxmd.com/read/29136948/gastroprotective-effect-and-mode-of-action-of-methanol-extract-of-sphenodesme-involucrata-var-paniculata-c-b-clarke-munir-lamiaceae-leaves-on-experimental-gastric-ulcer-models
#4
Puthanpura Sasidharan Sreeja, Karuppusamy Arunachalam, Sathyanarayanan Saikumar, Muniyandi Kasipandi, Sivaraj Dhivya, Rajan Murugan, Thangaraj Parimelazhagan
Sphenodesme involucrata var. paniculata (C. B. Clarke) Munir, endemic to South Asia, is used by tribal for alleviation from abdominal disorders, inflammation and body pain. However, the gastroprotective properties of this species have not yet been studied. The leaves of S. involucrata were extracted by Soxhlet extraction using different solvents successively and the extracts were analyzed for antioxidant and anti-Helicobacter pylori activities using different in vitro assays. The chemical composition of methanol extract of S...
November 9, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/29136918/simultaneous-grouping-and-ranking-with-combination-of-som-and-topsis-for-selection-of-preferable-analytical-procedure-for-furan-determination-in-food
#5
Renata Jędrkiewicz, Stefan Tsakovski, Aurore Lavenu, Jacek Namieśnik, Marek Tobiszewski
Novel methodology for grouping and ranking with application of self-organizing maps and multicriteria decision analysis is presented. The dataset consists of 22 objects that are analytical procedures applied to furan determination in food samples. They are described by 10 variables, referred to their analytical performance, environmental and economic aspects. Multivariate statistics analysis allows to limit the amount of input data for ranking analysis. Assessment results show that the most beneficial procedures are based on microextraction techniques with GC-MS final determination...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136906/comparison-of-common-components-analysis-with-principal-components-analysis-and-independent-components-analysis-application-to-spme-gc-ms-volatolomic-signatures
#6
Jihéne Bouhlel, Delphine Jouan-Rimbaud Bouveresse, Said Abouelkaram, Elisabeth Baéza, Catherine Jondreville, Angélique Travel, Jérémy Ratel, Erwan Engel, Douglas N Rutledge
The aim of this work is to compare a novel exploratory chemometrics method, Common Components Analysis (CCA), with Principal Components Analysis (PCA) and Independent Components Analysis (ICA). CCA consists in adapting the multi-block statistical method known as Common Components and Specific Weights Analysis (CCSWA or ComDim) by applying it to a single data matrix, with one variable per block. As an application, the three methods were applied to SPME-GC-MS volatolomic signatures of livers in an attempt to reveal volatile organic compounds (VOCs) markers of chicken exposure to different types of micropollutants...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136886/determination-of-terpenoid-contents-of-aromatic-plants-using-nirs
#7
Elif Ercioglu, Hasan Murat Velioglu, Ismail Hakki Boyaci
The method was developed in order to provide a fast, simple and non-destructive analysis of terpenoid compounds of aromatic plants. For this purpose, spectroscopic data were collected on the surface of dried plant samples by using near infrared spectroscopic (NIRS) analysis. Volatile substances were extracted from aromatic plants using hydro-distillation method to determine terpenoid composition by using gas chromatography-mass spectrometry (GC-MS). Multivariate calibration methods namely, partial least squares (PLS) regression, were used for data analysis...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136846/determination-of-bisphenols-with-estrogenic-activity-in-plastic-packaged-baby-food-samples-using-solid-liquid-extraction-and-clean-up-with-dispersive-sorbents-followed-by-gas-chromatography-tandem-mass-spectrometry-analysis
#8
M T García-Córcoles, M Cipa, R Rodríguez-Gómez, A Rivas, F Olea-Serrano, J L Vílchez, A Zafra-Gómez
Bisphenols (BPs) are a family of chemicals with known endocrine disrupting activity. Bisphenol A (BPA) is the most representative prototype of this group of chemicals. Recently, the use of BPA, a prototype of endocrine disruptors, has been reduced and replaced with structural analogs due to its negative effects on both the environment and consumers. In this work, a new method is presented for the determination of seven BPs, with estrogenic activity in ready-to-eat plastic packaged baby foods. The procedure involves the isolation of the analytes using solid-liquid phase extraction with acetonitrile followed by a clean-up step with a mixture of dispersive-SPE sorbents (C18 and PSA) and magnesium sulphate, to reduce matrix effect from proteins, sugars and lipids...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136841/miniaturized-quechers-based-methodology-for-multiresidue-determination-of-pesticides-in-odonate-nymphs-as-ecosystem-biomonitors
#9
Florencia Jesús, Ricardo Hladki, Natalia Gérez, Natalia Besil, Silvina Niell, Grisel Fernández, Horacio Heinzen, María Verónica Cesio
The impacts of the modern, agrochemicals based agriculture that threatens the overall systems sustainability, need to be monitored and evaluated. Seeking for agroecosystems monitors, the present article focus in the occurrence and abundance of aquatic macroinvertebrates, that have been frequently used as bioindicators of water quality due to their relationship with land use. Some of these organisms are on the top of the food chain, where bioaccumulation and biomagnification processes can be observed, and they can turn into secondary pollution sources of systems and terrestrial organisms as well...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136814/polyaniline-dicationic-ionic-liquid-coated-with-magnetic-nanoparticles-composite-for-magnetic-solid-phase-extraction-of-polycyclic-aromatic-hydrocarbons-in-environmental-samples
#10
Mohamad Shariff Shahriman, Muggundha Raoov Ramachandran, Nur Nadhirah Mohamad Zain, Sharifah Mohamad, Ninie Suhana Abdul Manan, Suhaila Mohd Yaman
In this present study, magnetic nanoparticles (MNPs) nanocomposites modified with polyaniline (PANI) coated newly synthesised dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesised as new generation material for magnetic solid phase extraction (MSPE). MNP-PANI-DICAT was characterised by FT-IR NMR, CHN, BET, SEM, TEM, and VSM techniques and the results were compared with MNP-PANI and native MNP. This new material was applied as a magnetic adsorbent for the pre-concentration and separation of polycyclic aromatic hydrocarbons (PAHs) due to the π-π interaction between polyaniline shell and dicationic ionic liquid (DICAT) with PAHs compounds...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136593/polycyclic-aromatic-hydrocarbons-and-organochlorine-pesticides-in-surface-water-from-the-yongding-river-basin-china-seasonal-distribution-source-apportionment-and-potential-risk-assessment
#11
Yizhen Wang, Shilu Zhang, Wenyan Cui, Xianzhi Meng, Xianqiang Tang
The presence of 17 polycyclic aromatic hydrocarbons (PAHs) and 15 persistent organochlorine pesticides (OCPs) in surface water of the Yongding River Basin was analyzed through GC/MS/MS during the spring and summer at 46 sampling sites. The goal was to investigate their seasonal distribution, possible sources, and potential risk. Our results showed that the total PAH concentration in surface water of Yongding River Basin ranged from 41.60 to 1482.60ng/L with a mean value of 137.85ng/L in the spring, and from 53...
November 11, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29135039/a-novel-fast-method-for-aqueous-derivatization-of-thc-oh-thc-and-thc-cooh-in-human-whole-blood-and-urine-samples-for-routine-forensic-analyses
#12
Fabio Stefanelli, Federica Giorgia Pesci, Mario Giusiani, Silvio Chericoni
A novel aqueous in situ derivatization procedure with propyl chloroformate (PCF) for the simultaneous, quantitative analysis of Δ(9) -tetrahydrocannabinol (THC), 11-hydroxy-Δ(9) -tetrahydrocannabinol (OH-THC) and 11-nor-Δ(9) -tetrahydrocannabinol-carboxylic acid (THC-COOH) in human blood and urine is proposed. Unlike current methods based on the silylating agent (BSTFA) added in an anhydrous environment, this new proposed method allows to add the derivatizing agent (propyl chloroformate, PCF) directly to the deproteinized blood and recover the derivatives by liquid-liquid extraction...
November 14, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/29135026/sensory-and-flavor-characteristics-of-tomato-juice-from-garden-gem-and-roma-tomatoes-with-comparison-to-commercial-tomato-juice
#13
Yaozhou Zhu, Charles A Sims, Harry J Klee, Paul J Sarnoski
The objective of this study was to characterize the flavor of a premium Florida tomato variety that has significant potential for producing a high quality processed juice product. A high-quality Florida plum tomato variety (Garden Gem), and a typical grocery-store plum tomato variety (Roma) were thermally processed into tomato juices without any additives. The 2 pilot products and a popular commercially available tomato juice (low sodium with sugar and flavor added) were compared using sensory evaluation and instrumental analysis...
November 14, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/29134791/qualitative-analysis-of-flavors-and-fragrances-added-to-tea-by-using-gc-ms
#14
Jianwu Wang, Yuanxin Hang, Tingting Yan, Jiahui Liang, Zhiqiang Huang, Huilan Xu
A precise identification method was developed to identify the flavors and fragrances added to tea matrix artificially using gas chromatography with mass spectrometry and gas chromatography with quadrupole time-of-flight mass spectrometry. The proposed method was based on the corresponding "three-column retention indices, two exact mass numbers, one mass spectrum matching degree" database of 40 kinds of common flavors and fragrances. The intra-day and the inter-day relative standard deviation of the retention indices were less than 0...
November 14, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/29131420/chromatographic-analysis-of-voc-patterns-in-exhaled-breath-from-smokers-and-nonsmokers
#15
Simonetta Capone, Maria Tufariello, Angiola Forleo, Valentina Longo, Lucia Giampietruzzi, Antonio Vincenzo Radogna, Flavio Casino, Pietro Siciliano
Cigarette smoking harms nearly every organ of the body and causes many diseases. The analysis of exhaled breath for exogenous and endogenous Volatile Organic Compounds (VOCs) can provide fundamental information on active smoking and insight into the health damage that smoke is creating. Various exhaled Volatile Organic Compounds (VOCs) have been reported as typical of smoking habit and recent tobacco consumption, but to date, no eligible biomarkers have been identified. Aiming to identify such potential biomarkers, in this pilot study we analysed the chemical patterns of exhaled breath from 26 volunteers divided in groups of nonsmokers and subgroups of smokers sampled at different periods of withdrawal from smoking...
November 13, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/29130673/-detection-of-11-organophosphate-pesticides-and-atrazine-in-water-by-dispersive-liquid-liquid-microextraction-combined-with-gas-chromatography-mass-spectrometry
#16
Chun-Yan Wang, Yue Yuan, Qian Wang, Ming-Xin Li, Pin-Pin Long, Xiao-Li Zou
OBJECTIVE: To develop a method for detecting 11 organophosphate pesticides and atrazine in water samples by dispersive liquidliquid microextraction combined with gas chromatographymass spectrometry (DLLMEGC/MS) . METHODS: DLLME and GCMS parameters were optimized for efficient extraction of chemicals. The proposed method was used for detecting organophosphate pesticides in tap water and river water samples,with 200 μL of dimethylbenzene as extractant and 800 μL of methanol as dispersant...
September 2017: Sichuan da Xue Xue Bao. Yi Xue Ban, Journal of Sichuan University. Medical Science Edition
https://www.readbyqxmd.com/read/29130499/combined-metabolomic-and-correlation-networks-analyses-reveal-fumarase-insufficiency-altered-amino-acids-metabolism
#17
Entai Hou, Xian Li, Zerong Liu, Fuchang Zhang, Zhongmin Tian
Fumarase catalyzes the interconversion of fumarate and L-malate in the tricarboxylic acid cycle. Fumarase insufficiencies were associated with increased level of fumarate and decreased level of malate and exacerbated salt-induced hypertension. To gain insights into the metabolism profiles that induced by fumarase insufficiency and identify key regulatory metabolites, we applied a GC-MS based metabolomics platform coupled with a network approach to analyze fumarase insufficient HUVEC cells and negative controls...
November 11, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/29129899/selective-production-of-acid-form-sophorolipids-from-glycerol-by-candida-floricola
#18
Masaaki Konishi, Tomotake Morita, Tokuma Fukuoka, Tomohiro Imura, Shingo Uemura, Hiroyuki Iwabuchi, Dai Kitamoto
Biosurfactants (BSs) are produced in abundance from various feedstocks by diverse microorganisms, and are used in various applications. In this paper, we describe a new yeast isolate that produces glycolipid-BSs from glycerol, with the aim of enhancing the utilization of the surplus glycerol produced by the oleo-chemical industry. As a result of the screening, strain ZM1502 was obtained as a potential producer of BS from glycerol. Based on TLC analysis, the strain produced glycolipid BSs. According to structural analyses (NMR, MALDI-TOF MS, and GC-MS), the main component of the glycolipids was 6',6"-di-O-acetylated acid-form sophorolipid (SL)...
November 13, 2017: Journal of Oleo Science
https://www.readbyqxmd.com/read/29129864/analysis-of-fresh-sap-collected-from-ryukyu-lacquer-tree
#19
Rong Lu, Takayuki Honda, Meesook Sung, Jaekook Jung, Tetsuo Miyakoshi
The chemical structure of fresh lacquer sap collected from a lacquer tree growing in Nago City of Okinawa, Japan, was analyzed by gas chromatography/mass-spectrometry (GC/MS) and nuclear magnetic resonance (NMR). The results showed that Nago lacquer is laccol lacquer and its major components are 3-(heptadeca-10Z,13E,15E-trienyl)catechol, 3-(heptadeca-10Z,13E-dienyl)catechol, 3-(heptadeca-14Z-enyl)catechol, and 3-(heptadeca-12Z-enyl)catechol, which are similar to the components of Vietnamese lacquer. It showed higher laccase activity at pH 5 - 8 and better low temperature adaptability than Vietnamese lacquer...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/29129857/estimation-of-retention-time-in-gc-ms-of-volatile-metabolites-in-fragrant-rice-using-principle-components-of-molecular-descriptors
#20
Nataporn Wijit, Sukon Prasitwattanaseree, Sugunya Mahatheeranont, Peter Wolschann, Supat Jiranusornkul, Piyarat Nimmanpipug
A quantitative structure-retention relationship (QSRR) study was applied for an estimation of retention times of secondary volatile metabolites in Thai jasmine rice. In this study, chemical components in rice seed were extracted using solvent extraction, then separated and identified by gas chromatography-mass spectrometry (GC-MS). A set of molecular descriptors was generated for these substances obtained from GC-MS analysis to numerically represent the molecular structure of such compounds. Principal component analysis (PCA) and principal component regression analysis (PCR) were used to model the retention times of these compounds as a function of the theoretically derived descriptors...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
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