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Ion mobility spectrometry

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https://www.readbyqxmd.com/read/28441352/high-throughput-determination-of-sodium-danshensu-in-beagle-dogs-by-the-lcms-ms-method-employing-liquid-liquid-extraction-based-on-96-well-format-plates
#1
Jingjing Jiang, Xin Zhao, Xiuxiu Li, Shengyuan Wu, Shidan Yu, Yuefen Lou, Guorong Fan
Sodium Danshensu (sodium d-(+)-β-(3,4-dihydroxyphenyl) lactate), one of the water-soluble ingredients in Salvia miltiorrhiza, exhibits potent relaxation of the coronary artery and anticoagulation effection. A high-throughput, rapid, and sensitive method combining liquid chromatography with electrospray ionization tandem mass spectrometry to determine the sodium danshensu in beagle dog plasma was developed and validated, using gallic acid as an internal standard (IS). Acidified plasma samples were extracted using 96-well liquid-liquid extraction, and were eluted on a CNW Athena C18 column (3 μm, 2...
April 25, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28441028/application-of-gc-ms-soft-ionization-for-isomeric-biological-compound-analysis
#2
Takeshi Furuhashi, Koji Okuda
Isomers are compounds with the same molecular formula. Many different types of isomers are ubiquitous and play important roles in living organisms. Despite their early discovery, the actual analysis of isomers has been tricky and has confounded researchers. Using mass spectrometry (MS) to distinguish or identify isomers is an emergent topic and challenge for analytical chemists. We review some techniques for analyzing isomers with emphasis on MS, e.g., the roles of ion reaction, hydrogen-deuterium exchange, ion mobility mass spectrometry, ion spectroscopy and energy change in producing isomer-specific fragments...
April 25, 2017: Critical Reviews in Analytical Chemistry
https://www.readbyqxmd.com/read/28439048/faecal-volatile-organic-compounds-analysis-using-field-asymmetric-ion-mobility-spectrometry-non-invasive-diagnostics-in-paediatric-inflammatory-bowel-disease
#3
Nora van Gaal, Rozanne Lakenman, James Covington, Richard Savage, Evelien de Groot, Marije Bomers, Marc Benninga, Chris Mulder, Nanne de Boer, Tim de Meij
Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), remains challenging to diagnose. Diagnostic work up carries a high burden, especially in paediatric patients, due to invasive endoscopic procedures. IBD is associated with alterations in intestinal microbiota composition. Faecal volatile organic compounds (VOCs) reflect gut microbiota composition. Aim of this study was to assess the diagnostic accuracy of faecal VOC profiling as non-invasive diagnostic biomarker for paediatric IBD...
April 25, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28438317/a-novel-chromatographic-approach-to-distinguish-gram-positive-from-gram-negative-bacteria-using-exogenous-volatile-organic-compound-metabolites
#4
Susana Ramírez-Guízar, Hannah Sykes, John D Perry, Edward C Schwalbe, Stephen P Stanforth, Ma Cristina I Perez-Perez, John R Dean
This paper utilized L-alanine aminopeptidase activity as a useful approach to distinguish between Gram-negative and Gram-positive bacteria. This was done using two enzyme substrates, specifically 2-amino-N-phenylpropanamide and 2-amino-N-(4-methylphenyl)propanamide which liberated the volatile compounds aniline and p-toluidine, respectively. Two complementary analytical techniques have been used to identify and quantify the VOCs, specifically static headspace multicapillary column gas chromatography ion mobility spectrometry (SHS-MCC-GC-IMS) and headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS)...
April 12, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28436597/glycan-analysis-by-ion-mobility-mass-spectrometry
#5
Johanna Hofmann, Kevin Pagel
Carbohydrates form one of the major classes of biological macromolecules in living organisms. To investigate their properties and function, an in-depth knowledge of their underlying structure is essential. However, the inherent structural complexity of glycans represents a major challenge. Carbohydrates are often branched and exhibit diverse regio- and stereochemistry. This in turn leads to a vast number of possible isomers, which are difficult to distinguish using established analytical tools. In the last decade, ion mobility-mass spectrometry, a technique that separates ions based on their mass, charge, size and shape, emerged as a powerful alternative for isomer distinction...
April 24, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28435985/elucidating-the-a%C3%AE-42-anti-aggregation-mechanism-of-action-of-tramiprosate-in-alzheimer-s-disease-integrating-molecular-analytical-methods-pharmacokinetic-and-clinical-data
#6
Petr Kocis, Martin Tolar, Jeremy Yu, William Sinko, Soumya Ray, Kaj Blennow, Howard Fillit, John A Hey
BACKGROUND: Amyloid beta (Aβ) oligomers play a critical role in the pathogenesis of Alzheimer's disease (AD) and represent a promising target for drug development. Tramiprosate is a small-molecule Aβ anti-aggregation agent that was evaluated in phase III clinical trials for AD but did not meet the primary efficacy endpoints; however, a pre-specified subgroup analysis revealed robust, sustained, and clinically meaningful cognitive and functional effects in patients with AD homozygous for the ε4 allele of apolipoprotein E4 (APOE4/4 homozygotes), who carry an increased risk for the disease...
April 24, 2017: CNS Drugs
https://www.readbyqxmd.com/read/28432656/collisional-cross-sections-with-t-wave-ion-mobility-spectrometry-without-experimental-calibration
#7
Daniel N Mortensen, Anna C Susa, Evan R Williams
A method for relating traveling-wave ion mobility spectrometry (TWIMS) drift times with collisional cross-sections using computational simulations is presented. This method is developed using SIMION modeling of the TWIMS potential wave and equations that describe the velocity of ions in gases induced by electric fields. The accuracy of this method is assessed by comparing the collisional cross-sections of 70 different reference ions obtained using this method with those obtained from static drift tube ion mobility measurements...
April 21, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28432653/analyzing-glycopeptide-isomers-by-combining-differential-mobility-spectrometry-with-electron-and-collision-based-tandem-mass-spectrometry
#8
J Larry Campbell, Takashi Baba, Chang Liu, Catherine S Lane, J C Yves Le Blanc, James W Hager
Differential mobility spectrometry (DMS) has been employed to separate isomeric species in several studies. Under the right conditions, factors such as separation voltage, temperature, the presence of chemical modifiers, and residence time can combine to provide unique signal channels for isomeric species. In this study, we examined a set of glycopeptide isomers, MUC5AC-3 and MUC5AC-13, which bear an N-acetyl-galactosamine (GalNAc) group on either threonine-3 or threonine-13. When analyzed as a mixture, the resulting MS and MS/MS spectra yield fragmentation patterns that cannot discern these convolved species...
April 21, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28429451/a-strong-cis-effect-in-an-imidazole-imidazolium-substituted-alkene
#9
Dayne C Georgiou, Mohammad A Haghighatbin, Conor F Hogan, Michael S Scholz, James N Bull, Evan J Bieske, David J D Wilson, Jason L Dutton
We report the first example of an alkene with two carbon-bound substituents (imidazole and imidazolium rings) where the Z-isomer has a greater thermodynamic stability than the E-isomer which persists in both the gas phase and in solution. Theoretical calculations, solution fluorescence spectroscopy and gas-phase ion mobility mass spectrometry studies confirm the preference for the Z-isomer, the stability of which is traced to a non-covalent interaction between the imidazole lone pair and the imidazolium ring...
April 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28429299/participation-of-c-h-protons-in-the-dissociation-of-a-proton-deficient-dipeptide
#10
Damodar Koirala, Sabyasachy Mistry, Paul G Wenthold
The dissociation of anionic dipeptides Phe*Gly and GlyPhe*, where Phe* refers to sulfonated phenyl alanine, has been investigated by using ion trap mass spectrometry. The dipeptides undergo collision-induced dissociation (CID) to give the same products, indicating that they rearrange to a common structure before dissociation. The rearrangement does not occur with the dipeptide methyl esters. The structures of the b2 ions were investigated to determine the effect that having a remote, anionic site has on product formation...
April 20, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28428246/key-features-of-an-hsp70-chaperone-allosteric-landscape-revealed-by-ion-mobility-native-mass-spectrometry-and-double-electron-electron-resonance
#11
Alex L Lai, Eugenia M Clerico, Mandy E Blackburn, Nisha A Patel, Carol V Robinson, Peter P Borbat, Jack H Freed, Lila M Gierasch
Proteins are dynamic entities that populate conformational ensembles, and most functions of proteins depend on their dynamic character. Allostery, in particular, relies on ligand-modulated shifts in these conformational ensembles. Hsp70s are allosteric molecular chaperones with conformational landscapes that involve large rearrangements of their two domains (viz, the nucleotide-binding domain and substrate-binding domain) in response to adenine nucleotides and substrates. However, it remains unclear how the Hsp70 conformational ensemble is populated at each point of the allosteric cycle and how ligands control these populations...
April 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28427262/melting-proteins-evidence-for-multiple-stable-structures-upon-thermal-denaturation-of-native-ubiquitin-from-ims-ms-measurements
#12
Tarick J El-Baba, Daniel W Woodall, Shannon A Raab, Daniel R Fuller, Arthur Laganowsky, David H Russell, David E Clemmer
Ion mobility and mass spectrometry techniques have been coupled with a new temperature-controlled electrospray ionization source in order to follow the structural transitions of ubiquitin in aqueous solution (pH = 3) at elevated solution temperatures (T = 26 to 96 °C). Changes in the charge state distribution are consistent with a two-state, cooperative unfolding transition having a melting temperature of Tm = 71 ± 2 °C, in agreement with prior calorimetric measurements [Wintrode, P. L.; Makhatadze, G. I...
April 20, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28421405/differential-fragmentation-of-mobility-selected-glycans-via-ultraviolet-photodissociation-and-ion-mobility-mass-spectrometry
#13
Kelsey A Morrison, Brian H Clowers
The alternative dissociation pathways initiated by ultraviolet photodissociation (UVPD) compared with collision-induced dissociation (CID) may provide useful diagnostic fragments for biomolecule identification, including glycans. However, underivatized glycans do not commonly demonstrate strong UV absorbance, resulting in low fragmentation yields for UVPD spectra. In contrast to UVPD experiments that leverage covalent modification of glycans, we detail the capacity of metal adduction to yield comparatively rich UVPD fragmentation patterns and enhance separation factors for an isomeric glycan set in a drift tube ion mobility system...
April 18, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28417307/investigating-differences-in-gas-phase-conformations-of-25-hydroxyvitamin-d3-sodiated-epimers-using-ion-mobility-mass-spectrometry-and-theoretical-modeling
#14
Christopher D Chouinard, Vinícius Wilian D Cruzeiro, Christopher R Beekman, Adrian E Roitberg, Richard A Yost
Drift tube ion mobility coupled with mass spectrometry was used to investigate the gas-phase structure of 25-hydroxyvitamin D3 (25OHD3) and D2 (25OHD2) epimers, and to evaluate its potential in rapid separation of these compounds. Experimental results revealed two distinct drift species for the 25OHD3 sodiated monomer, whereas only one of these conformations was observed for its epimer (epi25OHD3). The unique species allowed 25OHD3 to be readily distinguished, and the same pattern was observed for 25OHD2 epimers...
April 17, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28417171/resolution-optimized-headspace-gas-chromatography-ion-mobility-spectrometry-hs-gc-ims-for-non-targeted-olive-oil-profiling
#15
Natalie Gerhardt, Markus Birkenmeier, Daniel Sanders, Sascha Rohn, Philipp Weller
A prototype gas chromatography-ion mobility spectrometry (GC-IMS) system, hyphenating temperature-ramped headspace GC to a modified drift time IMS cell, was evaluated and compared to a conventional, isothermal capillary column (CC)-IMS system on the example of the geographical differentiation of extra virgin olive oils (EVOO) from Spain and Italy. It allows orthogonal, 2D separation of complex samples and individual detection of compounds in robust and compact benchtop systems. The information from the high-resolution 3D fingerprints of volatile organic compound (VOC) fractions of EVOO samples were extracted by specifically developed chemometric MATLAB® routines to differentiate between the different olive oil provenances...
April 17, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28414792/characterization-of-hydroxypropyl-beta-cyclodextrins-used-in-the-treatment-of-niemann-pick-disease-type-c1
#16
Alfred L Yergey, Paul S Blank, Stephanie M Cologna, Peter S Backlund, Forbes D Porter, Allan J Darling
2-Hydroxypropyl-beta-cyclodextrin (HPβCD) has gained recent attention as a potential therapeutic intervention in the treatment of the rare autosomal-recessive, neurodegenerative lysosomal storage disorder Niemann-Pick Disease Type C1 (NPC1). Notably, HPβCD formulations are not comprised of a single molecular species, but instead are complex mixtures of species with differing degrees of hydroxypropylation of the cyclodextrin ring. The degree of substitution is a critical aspect of the complex mixture as it influences binding to other molecules and thus could potentially modulate biological effects...
2017: PloS One
https://www.readbyqxmd.com/read/28409868/validated-uhplc-ms-ms-assay-for-quantitative-determination-of-etoposide-gemcitabine-vinorelbine-and-their-metabolites-in-lung-cancer-patients
#17
Xiaobin Gong, Le Yang, Feng Zhang, Youtian Liang, Shouhong Gao, Ke Liu, Wansheng Chen
A fully valid ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC- MS/MS) method was developed for the determination of etoposide, gemcitabine, vinorelbine and their metabolites (etoposide catechol, 2',2'-difluorodeoxyuridine and 4-O-deacetylvinorelbine) in human plasma. Multiple reaction monitoring (MRM) mode was performed with an electrospray ionization (ESI) interface operating in both the positive and negative ion modes per compound. The method required only 100 μL plasma with a one-step simple de-proteinization procedure, and a short run time of 7...
April 13, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28409865/retention-of-glycopeptides-analyzed-using-hydrophilic-interaction-chromatography-is-influenced-by-charge-and-carbon-chain-length-of-ion-pairing-reagent-for-mobile-phase
#18
Kenichiro Furuki, Toshimasa Toyo'oka
Characterization of the glycans of glycoproteins is essential for the development and production of biologics. Numerous methods are available for analyzing the glycans of glycoproteins directly and labeled glycans. Nevertheless, glycopeptides are difficult to resolve because of their exceptional complexity and the microheterogeneity of glycans. These properties represent technical challenges to efforts to insure the accurate characterization of biopharmaceuticals to comply with regulatory requirements. Therefore, we investigated the retention behavior of peptides and glycopeptides in hydrophilic interaction chromatography (HILIC)-mode HPLC in the presence of ion-pairing reagents...
April 13, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28409445/ion-mobility-spectrometry-high-resolution-ltq-orbitrap-mass-spectrometry-for-analysis-of-homemade-explosives
#19
Nathan Hagan, Ilana Goldberg, Adam Graichen, Amanda St Jean, Ching Wu, David Lawrence, Plamen Demirev
The detailed chemical characterization of homemade explosives (HMEs) and other chemicals that can mimic or mask the presence of explosives is important for understanding and improving the performance of commercial instrumentation used for explosive detection. To that end, an atmospheric-pressure drift tube ion mobility spectrometry (IMS) instrument has been successfully coupled to a commercial tandem mass spectrometry (MS) system. The tandem MS system is comprised of a linear ion trap and a high resolution Orbitrap analyzer...
April 13, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28407974/determination-of-antimony-compounds-in-waters-and-juices-using-ion-chromatography-inductively-coupled-plasma-mass-spectrometry
#20
Ya-An Lin, Shiuh-Jen Jiang, A C Sahayam
A method was developed by coupling ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS) for the speciation of antimony. In this study, antimony species such as antimonite [Sb(III)], antimonate [Sb(V)] and trimethyl antimony(V) (TMeSb) were separated in less than 8min using anion exchange chromatography with a Hamilton PRP-X100 column as the stationary phase. Mobile phase A was 20mmolL(-1) ethylenediaminetetraacetic acid (EDTA), 2mmolL(-1) potassium hydrogen phthalate (KHP) in 1% v/v methanol (pH 5...
September 1, 2017: Food Chemistry
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