Showing papers in "Journal of the American Society for Mass Spectrometry in 2011"

TL;DR: A substantial redesign of the custom-built 9.4 tesla FTICR mass spectrometer is described that improves sensitivity, acquisition speed, and provides an optimized platform for future instrumentation development.

TL;DR: It is demonstrated that paper spray mass spectrometry can be used to quantitatively measure drug concentrations over the entire therapeutic range for a wide variety of drugs.

TL;DR: This work experimentally verifies and proves the two long since postulated matrix-assisted laser desorption/ionization (MALDI) analyte protonation pathways known as the Lucky Survivor and the gas phase protonations model.

TL;DR: It is argued that TDA is not needed when accurate p-values of individual Peptide-Spectrum Matches are available and that it is easy to develop a non-TDA compliant tool that outperforms all TDA-compliant tools.

TL;DR: A prototype matrix-assisted laser desorption ionization time-of-flight MALDI-TOF mass spectrometer has been used for high-speed ion image acquisition and experiments aimed at improving conditions for continuous laser raster sampling for imaging are reported.

TL;DR: A new Fourier transform ion cyclotron resonance (FTICR) cell based on completely new principles of formation of the effective electric potential distribution in Penning type traps, Boldin and Nikolaev is constructed and tested experimentally.

TL;DR: This ‘software lock mass’ drastically improves mass accuracy compared with mass measurement without lock mass with none of the experimental cost of a physical lock mass, and it is integrated into the freely available MaxQuant analysis pipeline (www.maxquant.org).

TL;DR: ExMS automatically scans through high resolution MS data to find the individual isotopic peaks and isotopic envelopes of a list of peptides previously identified by MS/MS and performs a number of tests to ensure correct identification in spite of peptide overlap.

TL;DR: Results provide additional evidence that the origin of supercharging from aqueous solution is the result of chemical and/or thermal denaturation that occurs in the ESI droplet as the concentration of these supercharging reagents increases, and that proton transfer reactivity does not play a significant role in the charge enhancement observed.

TL;DR: The value of MALDI IMS to examine tissues for changes in lipid biochemistry and will provide data needed to eventually understand the biochemical mechanisms relevant to tissue injury is revealed.

TL;DR: Operations which, when applied to four different proteins ranging in size from 140 to 908 residues, routinely provides hundreds of useful unique peptides, covering the entire protein length many times over.

TL;DR: The novel aspects of this work reside in the fact that a TWIMS arrangement was used to obtain a high level structural information including location of fatty acyl substituents and double bonds for PCs in plasma, and the presence of alkali metal adduct ions such as [M + Li]+ was not required to obtain double bond positions.

TL;DR: As expected, resolution improves in He-rich gases: at 70% He, glycerolipid isomers with different fatty acid positions can be resolved, and these results open the door for application of FAIMS to lipids, particularly in shotgun lipidomics and targeted analyses of bioactive lipids.

TL;DR: Electron transfer dissociation (ETD) is being applied to structural identification of carbohydrates for the first time, and results in some new and detailed information for glycan structural studies, and the main mechanisms were investigated.

TL;DR: DMA-MS can distinguish nonspecific protein aggregates formed during the electrospray process from those formed preferentially in solution, and the observed charge versus diameter relation is compatible with a protein charge reduction mechanism based on the evaporation of triethylammonium ions from Electrosprayed drops.

TL;DR: A new instrument that combines ion mobility spectrometry (IMS) separations with tandem mass spectromaetry (MSn) is described and the ion characterization advantages of the new instrument are demonstrated with the analysis of the isomeric trisaccharides, melezitose and raffinose.

TL;DR: This investigation proves the viability of MALDI-MSI for studying the distribution of lipids directly in formalin fixed tissue, without any pretreatment protocols.

TL;DR: The correlation between SpCs of the same proteins across the different data sets was investigated and it was reported that TSpC normalization and NSAF normalization yielded almost ideal slopes of unity for normalized SpC versus average normalized SpCs, while NSP did not afford effective corrections of the unnormalized data.

TL;DR: The MALDI MS/MS response correlates well with the amount of INH determined to be in the tissues by high-performance liquid chromatography-MS/MS, thus simplifying the preparation.

TL;DR: The results of this study will direct the future synthesis of hydrophobic reagents for glycan analysis using the correlation between hydrophobicity and theoretical non-polar surface area calculation to facilitate the development of an optimum tag for gly can derivatization.

TL;DR: It is shown that ETD and supplemental collisional activation in a subsequent traveling wave ion guide allows for improved extraction of residue-specific deuterium contents in peptides with low charge.

TL;DR: Redshifts and broadening of the dispersed fluorescence spectra at high excitation laser power provide evidence of gradual heating of the ion population, pointing to a mechanism of sequential multiple-photon activation through absorption/emission cycling.

TL;DR: A range of strategies and tools have been developed to facilitate the determination of primary structures of analyte molecules of interest via tandem mass spectrometry (MS/MS), including ion-type definition and dissociation.

TL;DR: The computational results show that the proline effect mainly arises from the particularly low threshold energy for the amide bond cleavage N-terminal to the Pro-Ala residue, and from the high proton affinity of the pro line-containing C-Terminal fragment produced by this cleavage.

TL;DR: Ion mobility combined with electrospray ionization mass spectrometry have been used to extract the spectra of N-glycans released with PNGase F from a serial titration of recombinantly expressed envelope glycoprotein from the human immunodeficiency virus.

TL;DR: Graphene as adsorbent for solid-phase extraction of coronene from river water sample displays good performance with a detection limit of 10–7 M, and the ionization signal increases with the increasing number of benzene rings in the PAHs, suggesting that graphene binds toPAHs via π–π stacking interactions.

TL;DR: These approaches were shown to be successful in identifying “known unknowns” noted in LC-MS and even GC-MS analyses in the laboratory and were demonstrated in the identification of a variety of compounds of interest to others.

TL;DR: In this paper, a hybrid ion mobility-mass spectrometer (IM-MS) incorporating a variable-temperature (80-400 K) drift tube is presented, which utilizes an electron ionization (EI) source for fundamental small molecule studies.

TL;DR: An infrared laser was used to ablate materials under ambient conditions that were captured in solvent droplets that were deposited on a MALDI target or flow-injected into a nanoelectrospray source of an ion trap mass spectrometer.

TL;DR: The use of matrix pre-coated targets for imaging of lipids, peptides, and pharmaceuticals in tissues and does not require solvents that may lead to analyte delocalization within a tissue section is reported.