International Journal of Mass Spectrometry
Papers 5538
1 page of 554 pages (5,538 results)
Abstract A matrix-free laser desorption/ionization mass spectrometry (LDI-MS) approach was developed using electrospun composite nanofibers with controllable size, morphology and composition. Composite polyvinylpyrrolidone (PVP) nanofibers with added nanoparticles to enhance the absorption of laser energy absorber were studied. Fractal dimensional analysis was conducted to evaluate the electrospinning process for the first time, which provided useful information on the repeatability of nanofiber...
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Abstract This study presents a method to obtain power series expansions of toroidal harmonics in terms of radial and axial distances from the trapping circle. In order to obtain the power series expansion of individual toroidal harmonics, three-term recurrence relations are derived, which involve toroidal harmonics of order n − 1 , n, n + 1 and derivative of toroidal harmonic of order n. Using these three-term recurrence relations a systematic procedure is presented to obtain the power series ex...
Abstract The fragmentation statistics were analyzed to study the fragmentation characteristics of quadrupole ion trap CID (Collision Induced Dissociation) spectra extracted from the human peptide library in the NIST library. Instead of using intensity information, usually considered earlier, here the frequency of occurrence of the fragment ion peaks and its neutral loss events were analyzed with respect to the cleavage position along the peptide backbone and residue at the cleavage site. The ana...
Abstract Nonpolar triglycerides (TGs) are rarely detected in mass spectrometry imaging (MSI) experiments unless they are abundant in the sample. Herein, we use nanospray desorption electrospray ionization (nano-DESI) to explore the role of the solvent composition and ionic dopants on the detection of TGs in a murine gastrocnemius muscle tissue used as a model system. We evaluated three solvent mixtures for their ability to extract nonpolar TG species: MeOH:H2O 9:1 (v/v), MeOH:DCM 6:4 (v/v) and M...
Abstract This study presented a chemical protocol for purification of calcium and magnesium from a single aliquot of biological and geological samples. The separation protocol was based on a two-step cation exchange chromatography using DGA resin and AG50W-X12 (200–400 mesh) resin. Calcium fraction was first collected using 0.25 mL of DGA resin, and Mg fraction was then collected using 0.5 mL of AG50W-X12 cation exchange resin. For Ca isotope analysis, the effect of acidity and concentration mis...
Abstract The application of database search algorithms with very wide precursor mass tolerances for the “Open Search” paradigm has brought new efforts at post-translational modification discovery in shotgun proteomes. This approach has motivated the acceleration of database search tools by incorporating fragment indexing features. In this report, we compare open searches and sequence tag searches of high-resolution tandem mass spectra to seek a common “palette” of modifications when analyzing mu...
Abstract Glycosylation analysis from biological samples is often challenging due to the high complexity of the glycan structures found in these samples. In the present study N- and O- glycans from human colorectal cancer cell lines and human plasma were analyzed using ultrahigh resolution MALDI-FTICR-MS. N-glycans were enzymatically released from cell lines and plasma proteins, whereas beta-elimination was used for the release of O-glycans from the cells. The purified samples were mass analyzed ...
Abstract Surface ablation of tungsten, known as a plasma-facing material in fusion devices, was investigated mass-spectrometrically in ion beam-type experiments by exposing a tungsten surface in the presence of H2/D2 to fast atomic and molecular projectile ions with high electron-recombination energies (Ar+, He+ and N2+). The sputtered product ions were monitored by high resolution mass spectrometry, in the case of Ar+, at various beam energies, surface temperatures and partial pressures of D2 a...
Abstract Chemical ionization and thermal decomposition of proline have been investigated by corona discharge ion mobility spectrometry (CD-IMS) and high-level ab initio calculations. Five main peaks were observed in the ion mobility spectrum of proline at low cell temperatures while only two remained at high temperatures. Experimental and theoretical evidences were collected to link the observed peaks to the related ionic species. Two peaks were assigned to the protonated proline and its symmetr...
Abstract Synthetic polymers prepared by solid-phase processes are often released from the solid support by hydrolysis, leading to an acidic α chain-end which can usefully be employed to perform mass spectrometry experiments in the negative ion mode. This is the case for sequence-defined polyurethanes, which exhibit very simple MS/MS pattern as deprotonated species in great contrast to data obtained in the positive ion mode. Indeed, after deprotonation of their acidic end-group, collision induced...
Top fields of study
Analytical chemistry
Mass spectrometry
Atomic physics