journal
MENU ▼
Read by QxMD icon Read
search

Journal of the American Society for Mass Spectrometry

journal
https://www.readbyqxmd.com/read/30644055/various-multicharged-anions-of-ginsenosides-in-negative-electrospray-ionization-with-qtof-high-resolution-mass-spectrometry
#1
Nan Zhao, Mengchun Cheng, Shuai Huang, Dan Liu, Qiang Zhao, Yunpeng Bai, Xiaozhe Zhang
When characterizing components from ginseng, we found a vast number of multicharged anions presented in the liquid chromatography-mass spectrometry (LC-MS) chromatograms. The source of these anions is unclear yet, while ginsenosides, the major components of ginseng, are the main suspected type of molecules because of their sugar moiety. Our investigation using 14 pure ginsenosides affirmed that the multicharged anions were formed by ginsenosides rather than other types of ingredients in ginseng. Various anions could be observed for each ginsenoside...
January 14, 2019: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30644054/alfred-l-yergey-iii-september-17-1941-may-27-2018
#2
P Jane Gale, Stephanie M Cologna
No abstract text is available yet for this article.
January 14, 2019: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30617860/tio-2-photocatalyzed-oxidation-of-drugs-studied-by-laser-ablation-electrospray-ionization-mass-spectrometry
#3
Fred A M G van Geenen, Maurice C R Franssen, Ville Miikkulainen, Mikko Ritala, Han Zuilhof, Risto Kostiainen, Michel W F Nielen
In drug discovery, it is important to identify phase I metabolic modifications as early as possible to screen for inactivation of drugs and/or activation of prodrugs. As the major class of reactions in phase I metabolism is oxidation reactions, oxidation of drugs with TiO2 photocatalysis can be used as a simple non-biological method to initially eliminate (pro)drug candidates with an undesired phase I oxidation metabolism. Analysis of reaction products is commonly achieved with mass spectrometry coupled to chromatography...
January 7, 2019: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30617859/sweep-jet-collection-laser-induced-acoustic-desorption-atmospheric-pressure-photoionization-for-lipid-analysis-applications
#4
Kevin Benham, Facundo M Fernández, Thomas M Orlando
Laser-induced acoustic desorption coupled to microplasma-based atmospheric pressure photoionization (LIAD-APPI) using a nebulized sweep jet to aid in dopant introduction and ion transmission has been applied to the analysis of model, apolar lipid compounds. Specifically, several sterols, sterol esters, and triacylglycerols were detected using dopants such as anisole and toluene. Additionally, several triacylglycerols, sterols, carboxylic acids, and hopanoids were detected from complex mixtures of olive oil and Australian shale rock extract as a first demonstration of the applicability of LIAD-APPI on real-world samples...
January 7, 2019: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30604392/a-new-quantification-method-using-electrochemical-mass-spectrometry
#5
Chang Xu, Qiuling Zheng, Pengyi Zhao, Joseph Paterson, Hao Chen
Mass spectrometry-based quantification method has advanced rapidly. In general, the methods for accurate quantification rely on the use of authentic target compounds or isotope-labeled compounds as standards, which might be not available or difficult to synthesize. To tackle this grand challenge, this paper presents a novel approach, based on electrochemistry (EC) combined with mass spectrometry (MS). In this approach, a target compound is allowed to undergo electrochemical oxidation and then subject to MS analysis...
January 2, 2019: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30569429/gas-phase-chemistry-in-the-gc-orbitrap-mass-spectrometer
#6
Tim U H Baumeister, Nico Ueberschaar, Georg Pohnert
Gas-phase reactions of temporally stored ions play a significant role in trapped ion mass spectrometry. Especially highly labile ion species generated through electron ionization (EI) are prone to undergo gas-phase reactions after relaxation to a low vibrational state. Here, we show that in the C-Trap of the Q Exactive GC Orbitrap mass spectrometer, gaseous water reacts with radical cations of various compound classes. High-resolution accurate mass spectrometry of the resulting ions provides a key to the mechanistic understanding of the chemistry of high energetic species generated during EI...
December 19, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30569428/sulfur-transfer-versus-phenyl-ring-transfer-in-the-gas-phase-sequential-loss-of-ch-3-oh-and-ch-3-o-p-o-from-protonated-phosphorothioates
#7
Xiaoping Zhang, Honghan Chen, Yin Ji, Kezhi Jiang, Huanwen Chen
Collisional activation fragmentation of protonated phosphorothioates leads to skeletal rearrangement and formation of aryl sulfenylium cation (R-PhS+ ) via successive eliminations of CH3 OH and CH3 O-P=O. To better understand this unusual fragmentation reaction, isotope-labeling experiments and density functional theory (DFT) calculations were carried out to investigate two mechanistic pathways. In route 1, a direct intramolecular transfer of the R-phenyl group occurs from the oxygen atom to the sulfur atom on thiophosphoryl to form methoxyl S-(3-methyl-4-methylsulfanyl-phenyl) phosphonium thiolate (a4), which subsequently dissociates to form the m/z 169 cation...
December 19, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30569427/desi-spray-stability-in-the-negative-ion-mode-is-dependent-on-relative-humidity
#8
Clara L Feider, Rachel J DeHoog, Marta Sans, Jialing Zhang, Anna Krieger, Livia S Eberlin
Ambient ionization mass spectrometry (MS) techniques, such as desorption electrospray ionization (DESI), have been increasingly used due to their simplicity, minimal sample preparation requirements, and potential applications in the field and the clinic. However, due to their intrinsic nature, the performance of these methods is susceptible to variations in ambient conditions. Here, we present data that suggests DESI-MS analysis becomes inconsistent below a relative humidity (RH) level of ~ 35%. At low RH, we hypothesize that the DESI spray is subjected to frequent electrical discharges, resulting in unstable ionization and atypical mass spectra...
December 19, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30565163/cross-ring-fragmentation-patterns-in-the-tandem-mass-spectra-of-underivatized-sialylated-oligosaccharides-and-their-special-suitability-for-spectrum-library-searching
#9
Maria Lorna A De Leoz, Yamil Simón-Manso, Robert J Woods, Stephen E Stein
Reference spectral library searching, while widely used to identify compounds in other areas of mass spectrometry, is not commonly used in glycomics. Building on a study by Cotter and coworkers on analysis of sialylated oligosaccharides using atmospheric pressure-matrix-assisted laser-induced tandem mass spectrometry (MS/MS), we show that library search methods enable the automated differentiation of such sialylated oligosaccharide isomers using MS/MS derived from electrospray collision-induced dissociation in ion trap and beam-type fragmentation mass spectrometers...
December 18, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30560542/use-of-a-continuous-stirred-tank-reactor-for-the-determination-of-electrospray-response-factors-and-its-application-to-underivatized-sugars-under-various-solvent-parameters
#10
Jonathan B Thacker, Kevin A Schug
The relationship between the electrospray ionization (ESI)-mass spectrometric (MS) response of an analyte and its concentration has been well studied for permanently charged and basic analytes in the positive ionization mode, but there has been a lack of research effort for other analytes, and for the negative ionization mode, in general. In this study, this relationship was investigated for various adducts and deprotonated species of glucose, sucrose, and raffinose using a continuous stirred tank reactor (CSTR) coupled with ESI-tandem MS to obtain a continuum of response factors across a wide concentration range in both the positive and negative ionization modes with a single injection under 18 different combinations of solvents and additives...
December 17, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30560541/high-resolution-mass-spectrometry-quantification-impact-of-differences-in-data-processing-of-centroid-and-continuum-data
#11
L Vereyken, L Dillen, R J Vreeken, F Cuyckens
High-resolution mass spectrometry (HRMS) in full scan mode acquires all ions present in the sample of interest offering a lot of qualitative information. This, in combination with the improved performance of the new generation HRMS systems, triggers more (bio) analysts to switch from triple quad MS systems to HRMS for quantitative analysis. Quantitative processing of HRMS data is performed based on narrow mass extraction windows rather than on nominal mass product ion chromatograms (SRM or MRM). Optimal processing of HRMS data requires different considerations and software tools and can have an impact on data processing and final results...
December 17, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30552568/a-method-for-defining-the-position-of-ion-formation-in-a-maldi-tofms-by-analysis-of-the-laser-image-on-the-sample-surface
#12
Michelle Piotrowski, Brian Malys, Kevin G Owens
A method is developed to determine the position of ion formation along the flight axis of a MALDI TOFMS instrument using the image of the laser on the sample surface. Previous work (JASMS 2018, 29, 422-434) showed that misalignment of the sample stage in a Bruker Autoflex III MALDI TOFMS as well as multiple insertions/mountings of the target plate and differences in target plate shape itself produced reproducible changes in the measured ion time-of-flight which could be attributed to changes in the position of ion formation along the instrument flight axis...
December 14, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30552567/editorial-and-review-33-rd-asilomar-conference-on-mass-spectrometry-impact-of-metabolomics-in-translational-and-clinical-research
#13
EDITORIAL
Tim Garrett, Chris Petucci
No abstract text is available yet for this article.
December 14, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30547308/development-of-novel-free-radical-initiated-peptide-sequencing-reagent-application-to-identification-and-characterization-of-peptides-by-mass-spectrometry
#14
Kaylee Gaspar, Kimberly Fabijanczuk, Tara Otegui, Jose Acosta, Jinshan Gao
By incorporating a high proton affinity moiety to the charge localized free radical-initiated peptide sequencing (CL-FRIPS) reagent, FRIPS-MS technique has extended the applicability to hydrophobic peptides and peptides without basic amino acid residues (lysine, arginine, and histidine). Herein, the CL-FRIPS reagent has three moieties: (1) pyridine acting as the basic site to locate the proton, (2) 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO, a stable free radical) acting as the free radical precursor to generate the nascent free radical in the gas phase, and (3) N-hydroxysuccinimide (NHS) activated carboxylic acid acting as the coupling site to derivatize the N-terminus of peptides...
December 13, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30542974/a-microscale-planar-linear-ion-trap-mass-spectrometer
#15
Trevor K Decker, Yajun Zheng, Aaron J Ruben, Xiao Wang, Stephen A Lammert, Daniel E Austin, Aaron R Hawkins
The planar linear ion trap (PLIT) is a version of the two-dimensional linear quadrupole ion trap constructed using two facing dielectric substrates on which electrodes are lithographically patterned. In this article, we present a PLIT that was successfully miniaturized from a radius of 2.5 mm to a microscale radius of 800 μm (a scaling factor of 3.125). The mathematics concerning scaling an ion trap mass spectrometer are demonstrated-including the tradeoff between RF power and pseudopotential well depth...
December 12, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30523570/gas-phase-dynamics-of-collision-induced-unfolding-collision-induced-dissociation-and-electron-transfer-dissociation-activated-polymer-ions
#16
Jean R N Haler, Philippe Massonnet, Johann Far, Victor R de la Rosa, Philippe Lecomte, Richard Hoogenboom, Christine Jérôme, Edwin De Pauw
Polymer characterizations are often performed using mass spectrometry (MS). Aside from MS and different tandem MS (MS/MS) techniques, ion mobility-mass spectrometry (IM-MS) has been recently added to the inventory of characterization technique. However, only few studies have focused on the reproducibility and robustness of polymer IM-MS analyses. Here, we perform collisional and electron-mediated activation of polymer ions before measuring IM drift times, collision cross-sections (CCS), or reduced ion mobilities (K0 )...
December 6, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30523569/capturing-biology-in-flight
#17
Carol V Robinson
No abstract text is available yet for this article.
December 6, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30511236/ammonia-assisted-proton-transfer-reaction-mass-spectrometry-for-detecting-triacetone-triperoxide-tatp-explosive
#18
Qiangling Zhang, Xue Zou, Qu Liang, Hongmei Wang, Chaoqun Huang, Chengyin Shen, Yannan Chu
Proton transfer reaction mass spectrometry (PTR-MS) usually detects different types of compounds by changing the discharge gas to produce different reagent ions in the ion source. In the present work, a novel method of changing reagent ions, ammonia-assisted PTR-MS, was developed. Through an injection port bypass, ammonia was injected into a homemade PTR-MS device. A conventional PTR-MS apparatus with reagent ions H3 O+ (H2 O)n (n = 0, 1, 2) can be converted to an ammonia-assisted PTR-MS with reagent ions NH4 + ...
December 3, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30511235/insights-into-the-basal-activity-and-activation-mechanism-of-the-%C3%AE-1-adrenergic-receptor-using-native-mass-spectrometry
#19
Agni F M Gavriilidou, Hanna Hunziker, Daniel Mayer, Ziva Vuckovic, Dmitry B Veprintsev, Renato Zenobi
In the absence of orthosteric ligands, most G protein-coupled receptors (GPCRs) exist in an equilibrium of different conformational states. This equilibrium is shifted by an agonist towards the active state or by an inverse agonist towards the inactive state. The basal activity of the receptor, and its ability to activate intracellular signaling pathways, is defined by the probability that a fraction of the receptor adopts the active state in the absence of ligand. Despite breakthroughs in native MS of membrane proteins, GPCR-transducing complexes have not been studied by this approach until very recently...
December 3, 2018: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/30506347/untargeted-metabolomics-analytical-strategy-based-on-liquid-chromatography-electrospray-ionization-linear-ion-trap-quadrupole-orbitrap-mass-spectrometry-for-discovering-new-polyphenol-metabolites-in-human-biofluids-after-acute-ingestion-of-vaccinium-myrtillus
#20
Claudia Ancillotti, Marynka Ulaszewska, Fulvio Mattivi, Massimo Del Bubba
In this work, liquid chromatography, coupled with an electrospray ionization hybrid linear ion trap quadrupole/Orbitrap mass spectrometry, has been used to accurately identify polyphenol metabolites in human serum and urine after acute ingestion of a V. myrtillus berry supplement. The supplement was obtained by cryo-milling of bilberries, which were freeze-dried within 1 week after their harvesting, to maintain the berry native composition. Thirty-six derivatives of benzoic acids, hydroxyhippuric acids, cinnamic acids, phenylpropionic acids, phenylvaleric acids, phenylpentenoic acids and abscisic acid, together with two berry-native anthocyanins, one flavonol metabolite and two catechol derivatives were putatively identified in the investigated biofluids...
November 30, 2018: Journal of the American Society for Mass Spectrometry
journal
journal
30493
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"