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High performance liquid chromatography

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https://www.readbyqxmd.com/read/28231530/identification-of-a-novel-low-level-impurity-in-fungicide-pyraclostrobin-by-high-performance-liquid-chromatography-tandem-mass-spectrometry
#1
Kaimin Xia, ShanShan Shen, Qun Gao, Wei Shang, Yuanjiang Pan, Jun Wu
Pyraclostrobin is one kind of new type methoxy acrylate fungicides that has been widely used in agriculture at present, with a lot of advantages including broad spectrum, high efficiency and high selectivity. In this work, a novel low-level impurity in the pyraclostrobin at about 0.2% was separated and characterized by high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS). Firstly, the impurity was speculated to possess the same skeleton structure as the main product pyraclostrobin while the methyl group on the methyl ester was substituted to be CH2CH2Cl on the basis of the on-line multi-stage mass spectrometric behaviors compared with that of pyraclostrobin...
February 17, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28231253/community-analysis-of-pigment-patterns-from-37-microalgae-strains-reveals-new-carotenoids-and-porphyrins-characteristic-of-distinct-strains-and-taxonomic-groups
#2
Benoît Serive, Elodie Nicolau, Jean-Baptiste Bérard, Raymond Kaas, Virginie Pasquet, Laurent Picot, Jean-Paul Cadoret
Phytoplankton, with an estimated 30 000 to 1 000 000 species clustered in 12 phyla, presents a high taxonomic and ecophysiological diversity, reflected by the complex distribution of pigments among the different algal classes. High performance liquid chromatography is the gold standard method for qualitative and quantitative analysis of phytoplankton pigments in seawater and culture samples, but only a few pigments can be used as robust chemotaxonomic markers. A major challenge is thus to identify new ones, characteristic of a strain, species, class or taxon that cannot be currently identified on the basis of its pigment signature...
2017: PloS One
https://www.readbyqxmd.com/read/28231162/phenolic-pro%C3%AF-le-and-antioxidant-activity-of-melon-cucumis-melo-l-seeds-from-pakistan
#3
Alam Zeb
Phenolic composition of different extracts of honeydew melon seeds and their antioxidant activity was determined for the first time. Phenolic compounds were identified using a reversed phase high performance liquid chromatography with diode array detection (HPLC-DAD) method. Results showed the identification of five phenolic compounds in water extract namely gallic acid and its derivative, hydroxybenzoic acid and catechin derivatives and caffeic acid.There were nine phenolic compounds identified in methanol-water extract, which are caffeic acid, two vanillic acid derivatives, ellagitanins, quercetin-3-rutinoside, derivatives of syringic acid and ellagic acid...
October 17, 2016: Foods (Basel, Switzerland)
https://www.readbyqxmd.com/read/28231065/exposure-of-children-to-phthalates-and-the-impact-of-consumer-practices-in-slovakia
#4
Miroslava Šidlovská, Ida Petrovičová, Branislav Kolena, Tomáš Pilka, Eva Šovčíková, Tomáš Trnovec
Phthalates are environmental pollutants that can enter the human body by ingestion, inhalation and dermal absorption. Food constitutes the most important source of human exposure to these chemicals. The aim of our study was the biological monitoring of exposure to eight phthalate metabolites in children (n=107), 10-12 years of age, living in eastern Slovakia. Additionally, we analysed some associations between anthropometric measures, questionnaire data (i.e. eating and drinking habits, practice of personal care products) and concentrations of phthalate metabolites...
February 23, 2017: Reviews on Environmental Health
https://www.readbyqxmd.com/read/28231036/aqueous-humor-penetration-and-biological-activity-of-moxifloxacin-0-5-ophthalmic-solution-alone-or-with-dexamethasone-0-1
#5
Rachel L R Gomes, Rodrigo Galvão Viana, Luiz Alberto S Melo, Alessandro Carvalho Cruz, Eunice Mayumi Suenaga, Kenneth R Kenyon, Mauro Campos
PURPOSE: To compare aqueous humor concentrations of topically applied moxifloxacin 0.5% ophthalmic solution alone or in combination with dexamethasone 0.1% and to correlate these concentrations with the minimum inhibitory concentrations (MICs) for common endophthalmitis-causing organisms. METHODS: Sixty-eight patients undergoing routine phacoemulsification with intraocular lens implantation received either moxifloxacin 0.5% alone or moxifloxacin 0.5% combined with dexamethasone...
March 2017: Journal of Ocular Pharmacology and Therapeutics
https://www.readbyqxmd.com/read/28230966/increasing-peak-capacity-in-non-targeted-omics-applications-by-combining-full-scan-field-asymmetric-waveform-ion-mobility-spectrometry-with-liquid-chromatography-mass-spectrometry
#6
Kayleigh L Arthur, Matthew A Turner, James C Reynolds, Colin S Creaser
Full scan field asymmetric waveform ion mobility spectrometry (FAIMS) combined with liquid chromatography and mass spectrometry (LC-FAIMS-MS) is shown to enhance peak capacity for omics applications. A miniaturized FAIMS device capable of rapid compensation field scanning has been incorporated into an ultra-high performance liquid chromatography (UHPLC) and time-of-flight (TOF) mass spectrometry analysis, allowing the acquisition of full scan FAIMS and MS nested data sets within the timescale of a UHPLC peak...
February 23, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28230818/post-chornobyl-remote-radiation-effects-on-human-sperm-and-seminal-plasma-characteristics
#7
S V Andreychenko, A V Klepko, L V Gorban, O A Motryna, L V Grubska, O V Trofimenko
AIM: The research was aimed on analysis of the remote consequences of Chornobyl accident on the reproductive function of men adult residing in Ukraine. MATERIALS AND METHODS: 232 male volunteers with mean age of 34 years (range 20-47) from 5 different regions of Ukraine (Zhytomyr, Ivano-Frankivsk, Kyiv, Poltava, and Kyiv city) were enrolled in cross-sectional studies of long term radiation effects on seminal plasma and sperm. All manipulations, analysis and classification of ejaculates were done accordingly to WHO recommendations...
December 2016: Experimental Oncology
https://www.readbyqxmd.com/read/28230785/the-application-of-a-modified-d-roms-test-for-measurement-of-oxidative-stress-and-oxidized-high-density-lipoprotein
#8
Fumiaki Ito, Tomoyuki Ito, Chinatsu Suzuki, Tomoyo Yahata, Kazuyuki Ikeda, Kenji Hamaoka
Reactive oxygen species (ROS) are involved in the initiation and progression of atherosclerosis. ROS-derived hydroperoxides, as an indicator of ROS production, have been measured by using the diacron reactive oxygen metabolites (d-ROMs) test, which requires iron-containing transferrin in the reaction mixture. In this study we developed a modified d-ROMs test, termed the Fe-ROMs test, where iron ions were exogenously added to the reaction mixture. This modification is expected to exclude the assay variation that comes from different blood iron levels in individuals...
February 21, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28230759/analysis-of-the-total-biflavonoids-extract-from-selaginella-doederleinii-by-hplc-qtof-ms-and-its-in-vitro-and-in-vivo-anticancer-effects
#9
Hong Yao, Bing Chen, Yanyan Zhang, Huigen Ou, Yuxiang Li, Shaoguang Li, Peiying Shi, Xinhua Lin
Selaginella doederleinii Hieron has been traditionally used as a folk antitumor herbal medicine in China. In this paper, the phytochemical components of the total biflavonoids extract from S. doederleinii were studied by using high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF MS/MS) in negative ion mode, and their in vitro and in vivo anticancer effects were evaluated. Four types of biflavonoids from S. doederleinii, including IC3'-IIC8'', IC3'-IIC6'', IC3'-IIC3''', and C-O linked biflavonoids were examined originally using QTOF MS/MS...
February 20, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28229586/chlorhexidine-loaded-amorphous-calcium-phosphate-nanoparticles-for-inhibiting-degradation-and-inducing-mineralization-of-type-i-collagen
#10
Xue Cai, Bing Han, Yan Liu, Fucong Tian, Fuxin Liang, Xiaoyan Wang
A major shortcoming of contemporary dentin adhesives is their limited durability. Exposed collagen fibrils within the bonding interface are degraded by matrix metalloproteinases (MMPs), resulting in aging of the resin-dentin bond. In this study, chlorhexidine-loaded amorphous calcium phosphate (ACP) nanoparticles were synthesized to induce the mineralization of collagen fibrils. The nanoparticles sustainably released chlorhexidine, to inhibit MMPs during mineralization. Three types of ACP nanoparticles were prepared: N-ACP containing no chlorhexidine, C-ACP containing chlorhexidine acetate, and G-ACP containing chlorhexidine gluconate, which had a higher drug-loading than C-ACP...
February 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28228229/oxidative-transformation-of-a-tunichrome-model-compound-provides-new-insight-into-the-crosslinking-and-defense-reaction-of-tunichromes
#11
Adal Abebe, Qun F Kuang, Jason Evans, William E Robinson, Manickam Sugumaran
Tunichromes, small oligopeptides with dehydrodopa units isolated from the blood cells of ascidians, have been implicated in the defense reactions, metal binding, wound repair, or tunic formation. Their instability and high reactivity has severely hampered the assessment of their biological role. Experiments conducted with the model compound, 1,2-dehydro-N-acetyldopamine, indicated that the instability of tunichromes is due to this basic structure. Exposure of this catecholamine derivative to even mild alkaline condition such as pH 7...
February 16, 2017: Bioorganic Chemistry
https://www.readbyqxmd.com/read/28226282/systematic-identification-of-flavonols-flavonol-glycosides-triterpene-and-siraitic-acid-glycosides-from-siraitia-grosvenorii-using-high-performance-liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry-combined-with-a-screening-strategy
#12
Zhi-Xing Qing, Huan Zhao, Qi Tang, Chang-Ming Mo, Peng Huang, Pi Cheng, Peng Yang, Xue-Yi Yang, Xiu-Bin Liu, Ya-Jie Zheng, Jian-Guo Zeng
The fruits of Siraitia grosvenorii are considered to be health-promoting because of the diversity of their bioactive ingredients. In the present study, a screening method, using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC-Q-TOF-MS) combined with a screening strategy, has been established. The technology was used to systematically screening the targeted metabolites, primarily from the complex matrix of S. grosvenorii. The compounds were then identified by their exact masses and characteristic fragment ions, in comparison with the fragmentation behaviors of 19 references...
February 16, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28226266/parallel-artificial-liquid-membrane-extraction-of-new-psychoactive-substances-in-plasma-and-whole-blood
#13
Linda Vårdal, Hilde-Merete Askildsen, Astrid Gjelstad, Elisabeth Leere Øiestad, Hilde Marie Erøy Edvardsen, Stig Pedersen-Bjergaard
Parallel artificial liquid membrane extraction (PALME) was combined with ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) and the potential for screening of new psychoactive substances (NPS) was investigated for the first time. PALME was performed in 96-well format comprising a donor plate, a supported liquid membrane (SLM), and an acceptor plate. Uncharged NPS were extracted from plasma or whole blood, across an organic SLM, and into an aqueous acceptor solution, facilitated by a pH gradient...
February 14, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28225596/top-down-metabolomic-approaches-for-nitrogen-containing-metabolites
#14
Ryo Nakabayashi, Kei Hashimoto, Kiminori Toyooka, Kazuki Saito
Streamlining the processes that reveal heteroatom-containing metabolites and their biosynthetic genes is essential in integrated metabolomics studies. These metabolites are especially targeted for their potential pharmaceutical activities. By using a Fourier-transform ion cyclotron resonance-mass spectrometry (FTICR-MS) instrument, we provide top-down targeted metabolomic analyses using ultrahigh-resolution liquid chromatography-mass spectrometry (LC-MS), high-resolution matrix-assisted laser desorption/ionization (MALDI), and high-resolution imaging mass spectrometry (IMS) with (15)N labeling of nitrogen-containing metabolites...
February 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28225587/compms2miner-an-automatable-metabolite-identification-visualization-and-data-sharing-r-package-for-high-resolution-lc-ms-datasets
#15
William Matthew Bell Edmands, Lauren M Petrick, Dinesh Kumar Barupal, Augustin Scalbert, Mark Wilson, Jeffrey Wickliffe, Stephen M Rappaport
A long-standing challenge of untargeted metabolomic profiling by ultrahigh performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) is efficient transition from unknown mass spectral features to confident metabolite annotations. The compMS2Miner (Comprehensive MS2 Miner) package was developed in the R language to facilitate rapid, comprehensive feature annotation using a peak-picker-output and MS2 data files as inputs. The number of MS2 spectra that can be collected during a metabolomic profiling experiment far outweigh the amount of time required for pain-staking manual interpretation, therefore a degree of software workflow autonomy is required for broad-scale metabolite annotation...
February 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28225253/glutathione-adduct-patterns-of-michael-acceptor-carbonyls
#16
Christian Slawik, Christiane Rickmeyer, Martin Brehm, Alexander Böhme, Gerrit Schüürmann
Glutathione (GSH) has so far been considered to facilitate detoxification of soft organic electrophiles through covalent binding at its cysteine (Cys) thiol group, followed by stepwise catalyzed degradation and eventual elimination along the mercapturic acid pathway. Here we show that in contrast to expectation from HSAB theory, Michael-acceptor ketones, aldehydes and esters may form also single, double and triple adducts with GSH involving β-carbon attack at the much harder N-terminus of the γ-glutamyl (Glu) unit of GSH...
February 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28225187/new-application-of-chitosan-grafted-polyaniline-in-dispersive-solid-phase-extraction-for-the-separation-and-determination-of-phthalate-esters-in-milk-using-high-performance-liquid-chromatography
#17
Nourolhoda Razavi, Ali Sarafraz Yazdi
Chitosan-grafted polyaniline was synthesized and applied as a sorbent for the preconcentration of phthalate esters in dispersive solid-phase extraction. By coupling dispersive solid-phase extraction with high-performance liquid chromatography and response surface methodology (central composite design), a reliable, sensitive and cost-effective method for simultaneous determination of phthalate esters including dimethyl phthalate, di-n-butyl phthalate, and di(2-ethylhexyl)phthalate was developed. The morphology of sorbent had been studied by scanning electron microscopy and its chemical structure confirmed by Fourier transform infrared spectroscopy...
February 22, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28225164/effects-of-focal-brain-cooling-on-extracellular-concentrations-of-neurotransmitters-in-patients-with-epilepsy
#18
Sadahiro Nomura, Takao Inoue, Hirochika Imoto, Eiichi Suehiro, Yuichi Maruta, Yuya Hirayama, Michiyasu Suzuki
OBJECTIVE: Brain hypothermia controls epileptic discharge and reduces extracellular concentrations of glutamate (Glu), an excitatory neurotransmitter. We aimed to determine the effects of focal brain cooling (FBC) on levels of γ-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. The relationship between Glu or GABA concentrations and the severity of epileptic symptoms was also analyzed. METHODS: Patients with intractable epilepsy underwent FBC at lesionectomized (n = 11) or hippocampectomized (n = 8) regions at 15°C for 30 min using custom-made cooling devices...
February 22, 2017: Epilepsia
https://www.readbyqxmd.com/read/28224681/modeling-human-methamphetamine-use-patterns-in-mice-chronic-and-binge-methamphetamine-exposure-reward-function-and-neurochemistry
#19
James P Kesby, Ariel Chang, Athina Markou, Svetlana Semenova
Different methamphetamine use patterns in human subjects may contribute to inconsistent findings regarding the effects of methamphetamine abuse on brain and behavior. The present study investigated whether human-derived chronic and binge methamphetamine use patterns have differential effects on reward and neurochemistry in mice. Brain reward function in mice was evaluated during acute/prolonged withdrawal, and in response to methamphetamine challenge using the intracranial self-stimulation procedure. Brain dopaminergic, serotonergic and glutamatergic neurochemistry was determined with high-performance liquid chromatography...
February 21, 2017: Addiction Biology
https://www.readbyqxmd.com/read/28224246/comparison-of-veterinary-drug-residue-results-in-animal-tissues-by-ultrahigh-performance-liquid-chromatography-coupled-to-triple-quadrupole-or-quadrupole-time-of-flight-tandem-mass-spectrometry-after-different-sample-preparation-methods-including-use-of-a-commercial
#20
Tarun Anumol, Steven J Lehotay, Joan Stevens, Jerry Zweigenbaum
Veterinary drug residues in animal-derived foods must be monitored to ensure food safety, verify proper veterinary practices, enforce legal limits in domestic and imported foods, and for other purposes. A common goal in drug residue analysis in foods is to achieve acceptable monitoring results for as many analytes as possible, with higher priority given to the drugs of most concern, in an efficient and robust manner. The U.S. Department of Agriculture has implemented a multiclass, multi-residue method based on sample preparation using dispersive solid phase extraction (d-SPE) for cleanup and ultrahigh-performance liquid chromatography-tandem quadrupole mass spectrometry (UHPLC-QQQ) for analysis of >120 drugs at regulatory levels of concern in animal tissues...
February 21, 2017: Analytical and Bioanalytical Chemistry
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