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Ambient ionization

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https://www.readbyqxmd.com/read/27896697/metal-cationization-extractive-electrospray-ionization-mass-spectrometry-of-compounds-containing-multiple-oxygens
#1
Kenneth D Swanson, Sandra E Spencer, Gary L Glish
Extractive electrospray ionization is an ambient ionization technique that allows real-time sampling of liquid samples, including organic aerosols. Similar to electrospray ionization, the composition of the electrospray solvent used in extractive electrospray ionization can easily be altered to form metal cationized molecules during ionization simply by adding a metal salt to the electrospray solvent. An increase in sensitivity is observed for some molecules that are lithium, sodium, or silver cationized compared with the protonated molecule formed in extractive electrospray ionization with an acid additive...
November 28, 2016: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/27873315/incorporation-of-conjugated-fatty-acids-into-nile-tilapia-oreochromis-niloticus
#2
Elton G Bonafé, Luana C de Figueiredo, Alessandro F Martins, Johny P Monteiro, Oscar O S Junior, Edmilson A Canesin, Swami Arêa Maruyama, Jesuí V Visentainer
The aim of this work was to improve the nutritional quality of Nile tilapia meat through enriched diets with conjugated isomers of linolenic acid from tung oil. The transfer process of conjugated fatty acids (CFA) into fish muscle tissue was evaluated by gas chromatography-flame ionization detection (GC-FID) and Easy Ambient Sonic-Spray Ionization Mass Spectrometry (EASI-MS). The results showed that conjugated fatty acids were transferred from enriched diet for muscle tissue of Nile tilapia. Conjugated linoleic acids biosynthesis from conjugated linolenic acids was also observed after ten days...
November 21, 2016: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/27865893/sex-and-genetic-differences-in-the-effects-of-acute-diesel-exhaust-exposure-on-inflammation-and-oxidative-stress-in-mouse-brain
#3
Toby B Cole, Jacki Coburn, Khoi Dao, Pam Roqué, Yu-Chi Chang, Vrinda Kalia, Tomas R Guilarte, Jennifer Dziedzic, Lucio G Costa
In addition to increased morbidity and mortality caused by respiratory and cardiovascular diseases, air pollution may also contribute to central nervous system (CNS) diseases. Traffic-related air pollution is a major contributor to global air pollution, and diesel exhaust (DE) is its most important component. DE contains more than 40 toxic air pollutants and is a major constituent of ambient particulate matter (PM), particularly of ultrafine-PM. Limited information suggests that exposure to DE may cause oxidative stress and neuroinflammation in the CNS...
November 16, 2016: Toxicology
https://www.readbyqxmd.com/read/27830711/structure-conserving-spontaneous-transformations-between-nanoparticles
#4
K R Krishnadas, Ananya Baksi, Atanu Ghosh, Ganapati Natarajan, Thalappil Pradeep
Ambient, structure- and topology-preserving chemical reactions between two archetypal nanoparticles, Ag25(SR)18 and Au25(SR)18, are presented. Despite their geometric robustness and electronic stability, reactions between them in solution produce alloys, AgmAun(SR)18 (m+n=25), keeping their M25(SR)18 composition, structure and topology intact. We demonstrate that a mixture of Ag25(SR)18 and Au25(SR)18 can be transformed to any arbitrary alloy composition, AgmAun(SR)18 (n=1-24), merely by controlling the reactant compositions...
November 10, 2016: Nature Communications
https://www.readbyqxmd.com/read/27822645/comparison-of-paper-spray-mass-spectrometry-analysis-of-dried-blood-spots-from-devices-used-for-in-field-collection-of-clinical-samples
#5
Karen E Yannell, Kristina R Kesely, Huynh Dinh Chien, Candice B Kissinger, R Graham Cooks
Paper spray (PS) is an ambient ionization technique applicable to ionizing analytes from untreated dried biofluid samples. In-field sample analysis could benefit from the capability to use a finger prick of blood to measure drugs in whole blood at low cost and in a short time. Some studies may require specialized blood collection devices that can be used in remote areas. In this study, four different dried blood spot (DBS) devices are used with PS sources and tested for rapid quantification of imatinib and N-desmethyl-imatinib...
November 7, 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27802110/base-release-and-modification-in-solid-phase-dna-exposed-to-low-energy-electrons
#6
Surakarn Choofong, Pierre Cloutier, Léon Sanche, J Richard Wagner
Ionization generates a large number of secondary low-energy electrons (LEEs) with a most probable energy of approximately 10 eV, which can break DNA bonds by dissociative electron attachment (DEA) and lead to DNA damage. In this study, we investigated radiation damage to dry DNA induced by X rays (1.5 keV) alone on a glass substrate or X rays combined with extra LEEs (average energy of 5.8 eV) emitted from a tantalum (Ta) substrate under an atmosphere of N2 and standard ambient conditions of temperature and pressure...
November 1, 2016: Radiation Research
https://www.readbyqxmd.com/read/27782388/ambient-ionization-and-faims-mass-spectrometry-for-enhanced-imaging-of-multiply-charged-molecular-ions-in-biological-tissues
#7
Clara Leigh Feider, Natalia Elizondo, Livia S Eberlin
Ambient ionization mass spectrometry imaging (MSI) has been increasingly used to investigate the molecular distribution of biological tissue samples. Here, we report the integration and optimization of desorption electrospray ionization (DESI) and liquid-microjunction surface sampling probe (LMJ-SSP), and a chip-based high-field asymmetric waveform ion mobility spectrometry (FAIMS) device to image metabolites, lipids, and proteins in biological tissue samples. Optimized FAIMS parameters for specific molecular classes enabled semi-targeted detection of multiply-charged molecular species at enhanced signal-to-noise ratios (S/N), improved visualization of spatial distributions, and most importantly, allowed detection of species which were otherwise unseen by ambient ionization MSI alone...
October 26, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27778241/monitoring-toxic-ionic-liquids-in-zebrafish-danio-rerio-with-desorption-electrospray-ionization-mass-spectrometry-imaging-desi-msi
#8
Consuelo J Perez, Alessandra Tata, Michel L de Campos, Chun Peng, Demian R Ifa
Ambient mass spectrometry imaging has become an increasingly powerful technique for the direct analysis of biological tissues in the open environment with minimal sample preparation and fast analysis times. In this study, we introduce desorption electrospray ionization mass spectrometry imaging (DESI-MSI) as a novel, rapid, and sensitive approach to localize the accumulation of a mildly toxic ionic liquid (IL), AMMOENG 130 in zebrafish (Danio rerio). The work demonstrates that DESI-MSI has the potential to rapidly monitor the accumulation of IL pollutants in aquatic organisms...
October 24, 2016: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/27769383/rapid-detection-of-bacterial-endotoxins-in-ophthalmic-viscosurgical-device-materials-by-direct-analysis-in-real-time-mass-spectrometry
#9
Hongli Li, Victoria M Hitchins, Samanthi Wickramasekara
Bacterial endotoxins are lipopolysaccharides bound to the bacterial cell wall and released when bacteria rupture or disintegrate. Possible contamination of endotoxin in ophthalmic devices can cause a painful eye inflammation or result in toxic anterior segment syndrome after cataract surgery. Measurement of bacterial endotoxin in medical device materials is difficult since endotoxin binds with polymer matrix and some of the materials are very viscous and non-water soluble, where traditional enzyme-based Limulus amebocyte lysate (LAL) assay cannot be applied...
November 2, 2016: Analytica Chimica Acta
https://www.readbyqxmd.com/read/27767248/visible-light-induced-living-radical-polymerization-of-butyl-acrylate-photocatalyst-free-ultrafast-and-oxygen-tolerance
#10
Jiajia Li, Chunlai Ding, Zhengbiao Zhang, Xiangqiang Pan, Na Li, Jian Zhu, Xiulin Zhu
Butyl acrylate is polymerized in the living way under the irradiation of purple light-emitting diode (LED) or sunlight without photocatalyst at ambient temperature. 2-((Phenoxycarbonothioyl)thio) ethyl propanoate) is exclusively added and acted as an initiator and a chain transfer agent simultaneously in the current system. Poly(butyl acrylate) with well-regulated molecular weight and relatively narrow molecular weight distribution (Ð < 1.30) is synthesized. High conversion (>95%) can be achieved within several minutes...
October 21, 2016: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/27766565/direct-and-efficient-dehydrogenation-of-tetrahydroquinolines-and-primary-amines-using-corona-discharge-generated-on-ambient-hydrophobic-paper-substrate
#11
Kathryn M Davis, Abraham K Badu-Tawiah
The exposure of an aqueous-based liquid drop containing amines and graphite particles to plasma generated by a corona discharge results in heterogeneous aerobic dehydrogenation reactions. This green oxidation reaction occurring in ambient air afforded the corresponding quinolines and nitriles from tetrahydroquinolines and primary amines, respectively, at >96% yields in less than 2 min of reaction time. The accelerated dehydrogenation reactions occurred on the surface of a low energy hydrophobic paper, which served both as container for holding the reacting liquid drop and as a medium for achieving paper spray ionization of reaction products for subsequent characterization by ambient mass spectrometry...
October 20, 2016: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/27766177/direct-analysis-of-pharmaceutical-drugs-using-nano-desi-ms
#12
Carlos Cardoso-Palacios, Ingela Lanekoff
Counterfeit pharmaceutical drugs imply an increasing threat to the global public health. It is necessary to have systems to control the products that reach the market and to detect falsified medicines. In this work, molecules in several pharmaceutical tablets were directly analyzed using nanospray desorption electrospray ionization mass spectrometry (nano-DESI MS). Nano-DESI is an ambient surface sampling technique which enables sampling of molecules directly from the surface of the tablets without any sample pretreatment...
2016: Journal of Analytical Methods in Chemistry
https://www.readbyqxmd.com/read/27747956/high-pressure-mass-spectrometry-of-volatile-organic-compounds-with-ambient-air-buffer-gas
#13
Kenion H Blakeman, Craig A Cavanaugh, William M Gilliland, J Michael Ramsey
RATIONALE: There are many chemical measurement scenarios that would benefit from hand portable mass spectrometry tools including forensics, environmental monitoring, and safety and security. High pressure mass spectrometry (HPMS) facilitates miniaturization by significantly reducing vacuum system requirements. Previous work demonstrated HPMS using helium buffer gas, but HPMS conducted using ambient air would further reduce the size and weight of a portable instrument while also reducing logistical demands by eliminating the need for a helium supply...
October 17, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/27718044/the-osteoclasts-attach-to-the-bone-surface-where-the-extracellular-calcium-concentration-decreases
#14
Bilu Xiang, Yang Liu, Lu Xie, Qian Zhao, Ling Zhang, Xueqi Gan, Haiyang Yu
Osteoclasts demineralize and resorb bone once they attach to its surface. However, it's still unclear how the osteoclasts choose the specific sites for their attachments. It is postulated in this article that the decreased extracellular free ionized calcium concentration (Ca(2+)[e]) can provide a microenvironment for osteoclasts to recognize and then initiate the attachment process. The osteoclasts initially attach to the bone surface via integrating its integrin αvβ3 and RGD containing ligands in bone matrix...
October 7, 2016: Cell Biochemistry and Biophysics
https://www.readbyqxmd.com/read/27711702/fluorescent-zinc-ii-complexes-for-gene-delivery-and-simultaneous-monitoring-of-protein-expression
#15
Lalita B Rane, Anup N Kate, Shefali N Ramteke, Bhupendra V Shravage, Prasad P Kulkarni, Anupa A Kumbhar
Two new zinc(ii) complexes, [Zn(l-His)(NIP)](+)(1) and [Zn(acac)2(NIP)](2) (where NIP is 2-(naphthalen-1-yl)-1H-imidazo[4,5-f][1,10]phenanthroline, acac = acetyl acetone), have been synthesized and characterized by elemental analysis, UV-vis, fluorescence, IR, (1)H NMR and electron spray ionization mass spectroscopies. Gel retardation assay, atomic force microscopy and dynamic light scattering studies show that 1 and 2 can induce the condensation of circular plasmid pBR322 DNA into nanometer size particles under ambient conditions...
October 3, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/27709900/aerosol-chemistry-resolved-by-mass-spectrometry-insights-into-particle-growth-after-ambient-new-particle-formation
#16
Alexander L Vogel, Johannes Schneider, Christina Müller-Tautges, Thomas Klimach, Thorsten Hoffmann
Atmospheric oxidation of volatile organic compounds (VOCs) yields a large number of different organic molecules which comprise a wide range of volatility. Depending on their volatility, they can be involved in new particle formation and particle growth, thus affecting the number concentration of cloud condensation nuclei in the atmosphere. Here, we identified oxidation products of VOCs in the particle phase during a field study at a rural mountaintop station in central Germany. We used atmospheric pressure chemical ionization mass spectrometry ((-)APCI-MS) and aerosol mass spectrometry for time-resolved measurements of organic species and of the total organic aerosol (OA) mass in the size range of 0...
October 6, 2016: Environmental Science & Technology
https://www.readbyqxmd.com/read/27704473/direct-visualization-of-neurotransmitters-in-rat-brain-slices-by-desorption-electrospray-ionization-mass-spectrometry-imaging-desi-ms
#17
Anna Maria A P Fernandes, Pedro H Vendramini, Renan Galaverna, Nicolas V Schwab, Luciane C Alberici, Rodinei Augusti, Roger F Castilho, Marcos N Eberlin
Mass spectrometry imaging (MSI) of neurotransmitters has so far been mainly performed by matrix-assisted laser desorption/ionization (MALDI) where derivatization reagents, deuterated matrix and/or high resolution, or tandem MS have been applied to circumvent problems with interfering ion peaks from matrix and from isobaric species. We herein describe the application of desorption electrospray ionization mass spectrometry imaging (DESI)-MSI in rat brain coronal and sagittal slices for direct spatial monitoring of neurotransmitters and choline with no need of derivatization reagents and/or deuterated materials...
October 4, 2016: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/27704091/online-coupling-techniques-in-ambient-mass-spectrometry
#18
Shuting Xu, Yiding Zhang, Linnan Xu, Yu Bai, Huwei Liu
Since ambient mass spectrometry (AMS) has been proven to have low matrix effects and high salt tolerance, great efforts have been made for online coupling of several analytical techniques with AMS. These analytical techniques include gas chromatography (GC), liquid chromatography (LC), capillary electrophoresis (CE), surface plasmon resonance (SPR), and electrochemistry flow cells. Various ambient ionization sources, represented by desorption electrospray ionization (DESI) and direct analysis in real time (DART), have been utilized as interfaces for the online coupling techniques...
October 17, 2016: Analyst
https://www.readbyqxmd.com/read/27701818/molecular-imaging-of-growth-metabolism-and-antibiotic-inhibition-in-bacterial-colonies-by-laser-ablation-electrospray-ionization-mass-spectrometry
#19
Hang Li, Pranav Balan, Akos Vertes
Metabolism in microbial colonies responds to competing species, rapidly evolving genetic makeup, and sometimes dramatic environmental changes. Conventional characterization of the existing and emerging microbial strains and their interactions with antimicrobial agents, e.g., the Kirby-Bauer susceptibility test, relies on time consuming methods with limited ability to discern the molecular mechanism and the minimum inhibitory concentration. Assessing the metabolic adaptation of microbial colonies requires their non-targeted molecular imaging in a native environment...
October 4, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27682673/-determination-of-tert-butyl-alcohol-in-the-air-of-the-workplace-by-solvent-desorption-gas-chromatography
#20
T D Li, F Liu, Y X Xie, J H Chen
Objective: To establish solvent desorption gas chromatographic method for determination of tert-butyl alcohol in the air of the workplace. Methods: After tert-butyl alcohol in the air of the workplace collected with activated carbon tube and desorbed with 2% 2-propanol in CS2, and then separated with DB-FFAP capillary column and detected with flame ionization detector. Results: The linearity ranges were 0.6~2 264.0 mg/L. The limit of quantification was 0.6 mg/L. The determination has a good reproducibility...
August 20, 2016: Chinese Journal of Industrial Hygiene and Occupational Diseases
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