scholarly journals Consequences of the mass spectrometric and infrared analysis of oils and asphaltenes for the chemistry of coal liquefaction. Characterization of coal-derived liquids and other fossil fuel related materials employing mass spectrometry

1979 ◽  
Author(s):  
P. Benson ◽  
S. Scheppele ◽  
G. Greenwood ◽  
T. Aczel ◽  
Q. Grindstaff ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Fossil Fuel ◽  
Mass Spectrometric ◽  
Coal Liquefaction ◽  
Infrared Analysis

Protein mass measurement combined with mass spectrometric sequencing of protein digests for detection and characterization of protein modifications1

2006 ◽  
Vol 84 (7) ◽  
pp. 986-997 ◽  
Author(s):  
Chengjie Ji ◽  
Zhengping Wang ◽  
Liang Li
Keyword(s):  
Mass Spectrometry ◽  
Gel Electrophoresis ◽  
Protein Modification ◽  
Mass Spectrometric ◽  
Maldi Ms ◽  
Intact Protein ◽  
Protein Mass ◽  
Cell Extracts ◽  
Peptide Mass

A method for the characterization of modifications of low molecular weight proteins (<20 kDa) extracted from a microorganism based on the use of multiple separation tools and mass spectrometric techniques is described. In this method, intact proteins from cell extracts are first separated and fractionated by liquid chromatography (LC). Individual fractions are then analyzed by matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) to provide intact protein mass information. The fractions are further characterized by using trypsin digestion and LC electrospray ionization (ESI) MS/MS analysis of the resultant peptides to identify the proteins. Gel electrophoresis of a fraction is also carried out to estimate the molecular masses of the proteins. The gel bands are identified by in-gel digestion and peptide mass mapping and sequencing using MALDI-MS and MALDI-MS/MS. The combined information generated from these experiments is interpreted for detecting and characterizing modified proteins. This method has been developed and applied to the analysis of posttranslational modifications (PTMs) of low-mass proteins (5–20 kDa) extracted from a relatively well-characterized microorganism, Escherichia coli. Using this method, not only previously reported PTMs involving acetylation, methylation, oxidation, and the removal of signal peptides, but also two novel PTMs, namely loss of N-terminal Met-Thr-Met (MTM) and hydroxylation of arginine, were identified. It is envisaged that this method should be applicable to other relatively simple microorganisms for the discovery of new PTMs.Key words: top-down proteomics, protein modification, HPLC, gel electrophoresis, tandem mass spectrometry.

Mass Spectrometry of Oligomeric Cyanines and Squaraines of the Indole Series: Fast Atom Bombardment-Induced Chemical Reactions

2002 ◽  
Vol 57 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Thomas Dülcks ◽  
Walter Grahn ◽  
Hans-Hermann Johannes ◽  
Ulf Lawrentz ◽  
Miriam Rittner ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Chemical Reactions ◽  
Relative Abundance ◽  
Fast Atom Bombardment ◽  
Mass Spectrometric ◽  
Indole Series

Fast atom bombardment (FAB) has been used for mass spectrometric characterization of oligomeric cyanines and squaraines of the indole series which are linked by different aromatic spacers. Markedly different results were obtained for the oligomers and for the corresponding monomers. In addition to the expected mono-anions and mono-cations, ions of high relative abundance were detected which can only be explained on the basis of FAB-induced chemical reactions of the initial oligomers. Formation of allenes, hydrogenation and dehydrogenation, respectively, is characteristic for this class of compounds under FAB-conditions.

scholarly journals Mass spectrometric characterization of oligomeric phosphaalkenes

2017 ◽  
Vol 95 (3) ◽  
pp. 239-242 ◽  
Author(s):  
Bronwyn H. Gillon ◽  
Derek P. Gates ◽  
Matthew A. Henderson ◽  
Eric Janusson ◽  
J. Scott McIndoe
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Phosphine Oxide ◽  
Silver Ions ◽  
Mass Spectrometric ◽  
Ionization Mass ◽  
Similar Distribution ◽  
Sodium Ions ◽  
High Affinity

Oligomeric phosphaalkenes are readily characterized using electrospray ionization mass spectrometry (ESI-MS). The high affinity of phosphines for silver ions permits the detection of the unadulterated polymer as [M + xAg]x+ ions (x = 2–3). When the oligomers are oxidized using H2O2, the resulting phosphine oxide polymer may be treated with sodium ions to produce [M + xNa]x+ ions (x = 2–3). Both methods predict a similar distribution of oligomers: Mn values of 3450 ± 100 Da and a PDI of 1.09 ± 0.01 cover both analyses. This distribution represents oligomers of the general formula Me(PMesCPh2)nH from n = 4–20, maximizing at ∼n = 10.

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