Showing papers in "Journal of the American Society for Mass Spectrometry in 2003"

TL;DR: The results indicated that both ionization types showed matrix effect, but ESI was more susceptible than APCI, while SPE was necessary for extensive clean up of plasma prior to LC-APCI-MS/MS.

TL;DR: The effect of flow rate on ion signals was studied systematically using mixtures of compounds with different physicochemical properties to find the functional dependence of certain analyte-ion ratios upon the flow rate can be correlated to changes in analyte partition during droplet fission prior to ion release.

TL;DR: The new fragmentation pathways established by tandem and source CAD tandem mass spectra of various PC molecules, including deuterium-labeling analogs, were proposed to clarify the mechanisms underlying the ion formations that lead to the structural characterization of PC molecules.

TL;DR: A systematic nomenclature is proposed to describe the types of peptides that are generated after proteolysis of crosslinked proteins, their fragmentation by tandem mass spectrometry, and an automated algorithm for MS/MS spectral assignment called “MS2Assign.”

TL;DR: Peptide mass fingerprinting grew from a need for a faster, more efficient method to identify frequently observed proteins in electrophoresis gels and laid the foundation for high-throughput, high-sensitivity methods of protein analysis, now known as proteomics.

TL;DR: The protocol employs a Nd:Yag laser and describes both sample handling and instrument conditions which consistently yield reproducible MALDI TOF mass spectra with greater than 25 peaks from both gram-positive and gram-negative bacteria.

TL;DR: As a consequence of the strong dependence of the axial field on radial displacement, trapped thermalized ions can be ejected axially from a linear ion trap in a mass-selective way when their radial amplitude is increased through a resonant response to an auxiliary signal.

TL;DR: Improved proteome coverage can be obtained using a combination of these ionization techniques, and a significant degree of overlap was observed between the proteins identified in the LC/ESI/MS/MS and LC/MALDI/ MS/MS data sets.

TL;DR: Results indicate that AMT database searches with modest mass and elution time criteria can provide proteomic information for approximately one thousand proteins in a single run of <3 h, and demonstrate the utility of the AMT tag approach using capillary LC-TOF MS instruments, and also show thatAMT tags developed using other instrumentation can be effectively utilized.

TL;DR: In this paper, the authors proposed a method for quantifying differentially labeled proteins on an ion trap mass spectrometer with a mass resolution of about 2000 in automated data dependent LC-MS/MS acquisition mode.

TL;DR: A new sample preparation method for MALDI based on the use of a mixture of the two commonly used matrices, DHB and CHCA, is described, which results in increased sequence coverage and spot-to-spot reproducibility for peptide mass mapping and facilitates automated data acquisition.

TL;DR: The FAIMS method responds to changes in ion mobility at high field rather than absolute values of ion mobility, and was shown to provide efficient separation and identification of disaccharide isomers at high sensitivity, and could be applied to a larger group of carbohydrates.

TL;DR: The photocatalytic degradation of the organophosphorus insecticide diazinon in aqueous suspensions has been studied by using titanium dioxide as a photocatalyst and similarities to the metabolic pathways occurring in living organisms were observed.

TL;DR: The rapid development of mass spectrometric technologies applied to protein research has catalyzed entirely new experimental approaches and opened up new types of biological questions to experimentation, culminating in the field of proteomics.

TL;DR: Improved sequence coverage in combination with enzymatic digestions of different specificity is proposed as a method for analysis of post-translational modification from 2D-gel separated proteins.

TL;DR: Electron capture dissociation (ECD) and collision-induced Dissociation (CID) are demonstrated to be effective in the detection and localization of the methionine sulfoxide residues in peptides using Fourier transform ion cyclotron resonance (FTICR) mass spectrometry.

TL;DR: The results from an intercomparison of accurate mass measurement of a small molecule across a broad range of mass spectrometers are reported, and it is possible to define the uncertainty associated with the elemental formulae derived from accurate mass measurements.

TL;DR: A number of sample preparation and matrix deposition protocols are evaluated for spatial profiling of Aplysia californica exocrine gland and neuronal tissues, finding electrospray matrix deposition and a variety of freezing methods to be optimum for these invertebrate tissues.

TL;DR: The method has been validated in terms of sensitivity, selectivity, accuracy, and precision and was applied to the analysis of water and sludge samples from drinking water treatment plant (DWTP) of Barcelona.

TL;DR: To investigate gas-phase fragmentations and characteristic ions arising from methylated and unmodified arginine residues in detail, peptides containing these residues were subjected to electrospray triple-quadrupole tandem mass spectrometry and revealed that dimethylammonium is a specific marker ion for aDMA.

TL;DR: The gas phase reactions of protonated tryptophan have been examined in a quadrupole ion trap using a combination of collision induced dissociation, hydrogen–deuterium exchange, regiospecific deuterium labeling and molecular orbital calculations to demonstrate that the activation barriers to intramolecular proton transfer are lower than that for NH3 loss.

TL;DR: Online high performance liquid chromatography and electrospray ionization-mass spectrometry are used to separate and directly characterize DMPO oxygen-centered radical adducts formed from the reaction of Fe2+ with t-butyl or cumene hydroperoxide.

TL;DR: This work compares and explores the use of alternative pyridyl ligands, including 4,7-diphenyl-1,10-phenanthroline, and three groups of flavonoid glycoside isomers are differentiated, including glycosides of apigenin, quercetin, and luteolin.

TL;DR: The utility of reducing terminal derivatives and control of precursor ion charge state for tandem mass spectrometric strategies for determining GalNAc sulfation positional isomers of CS are described.

TL;DR: New oxidation products and free radicals derived from tryptophan (Trp) oxidation under Fenton reaction conditions were identified using mass spectrometry and the proposed structure of the observed adducts was confirmed.

TL;DR: For the first time estrogen DNA-adducts were identified in DNA human breast tumor tissue using nano-LC coupled to nano-Electrospray Tandem Mass Spectrometry and no straightforward difference was observed.

TL;DR: The utility of post-source decay (PSD) matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was investigated for the structural analysis of phosphatidylcholine and preferential loss of sn-1 fatty acid group was explained.

TL;DR: It is indicated that selenium atoms are lost from selenoproteins during purification and characterization through the mechanism of oxidation of selenocysteine residue to selenoxide followed by syn-β-elimination of se lenenic acid during sample processing.

TL;DR: HPLC-MS/MS can be used to successfully characterize unknown viruses in infected plants and several of the differentially expressed protein spots were identified as proteins of potato virus X (PVX), thus successfully identifying the causative agent of the uncharacterized viral infection.

TL;DR: The present LC-MS method identified 75% of the compounds contained in these samples, including 8% that the other two techniques failed to identify, and is complementary to GC-MS and/or HPLC-DAD and helps enlarge the range of drugs detected in clinical toxicology.