Analysis of Testosterone Esters by Tandem Mass Spectrometry

1993 ◽  
Vol 76 (2) ◽  
pp. 306-312 ◽  
Author(s):  
Thomas Cairns ◽  
Emil G Siegmund ◽  
Bobby Rader
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Relative Abundance ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Generic Product ◽  
Tandem Mass ◽  
Fragment Ions ◽  
Product Ions ◽  
The Individual

Abstract The electron ionization (El) and chemical ionization (CI) mass spectra of 12 representative testosterone esters were examined to explore the various analytical options available for identification and confirmation of the esters. Using El, a number of fragment ions indicated the identification of the testosterone moiety, but structural confirmation of the individual esters often required the observance of the molecular ion at very low relative abundance ratios. The acceptable analytical method involved CI/tandem mass spectrometry based on the production of the 2 generic product ions derived from the protonated molecule ion.

Optimization of pyrolysis–desorption chemical ionization mass spectrometry and tandem mass spectrometry of polysaccharides

1994 ◽  
Vol 72 (2) ◽  
pp. 345-351 ◽  
Author(s):  
R.J. Helleur ◽  
Pierre Thibault
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Chemical Ionization ◽  
Operating Conditions ◽  
High Mass ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Tandem Mass ◽  
Mass Fragment ◽  
Fragment Ions

The operating conditions for pyrolysis–desorption ammonia chemical ionization mass spectrometry and tandem mass spectrometry have been optimized and the technique evaluated for the production and analysis of structurally-informative pyrolytic fragmentation ions corresponding to intact anhydrohexose oligosaccharides, using amylose as the model polysaccharide. Among the various parameters examined it was found that the nature of the solvent used to adhere the sample to the emitter coil and the configuration of the emitter and the rate at which it is heated all play important roles in determining the efficiency of the pyrolytic process and the production of high mass fragment ions. Adjustment of reagent gas pressure together with source temperature also influence the chemical integrity of high mass oligomeric pyrolysis products. Under optimal operating conditions using ammonia reagent gas, the analyses of cellulose, laminarin, agars, and chitin gave relatively abundant ions corresponding to ammonium (or protonated) adducts of up to anhydrohexose tetrasaccharide. More importantly, the generation of such higher mass fragment ions provided a sustained ionic current of sufficient duration to perform tandem mass spectrometric analyses.

scholarly journals Analysis of Additives in Polyethylene with Desorption Chemical Ionization/Tandem Mass Spectrometry

1993 ◽  
Vol 47 (6) ◽  
pp. 844-851 ◽  
Author(s):  
S. W. Chen ◽  
G. R. Her
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Collision Induced Dissociation ◽  
Low Molecular Weight ◽  
Tandem Mass ◽  
Desorption Chemical Ionization ◽  
Great Confidence ◽  
Ionization Tandem Mass Spectrometry

Desorption chemical ionization with ammonia as the reagent gas in combination with tandem mass spectrometry is described for the analysis of additives in polyethylene. The additives were extracted with toluene and then analyzed directly by desorption chemical ionization and tandem mass spectrometry. With ammonia as the reagent gas, mass spectra of additives were found to contain intense pseudomolecular ions with very little fragmentation. In addition, low-molecular-weight polyethylene molecules extracted with the additives were barely detectable, and thus there was less likelihood of interference. Collision-induced dissociation of the pseudomolecular ions provided great confidence in the assignment of additives.

Recent developments in the structural characterization of substituted meso-tetraarylporphyrins by electrospray tandem mass spectrometry

2009 ◽  
Vol 13 (04n05) ◽  
pp. 524-527 ◽  
Author(s):  
M. Rosário M. Domingues ◽  
Pedro Domingues ◽  
Maria G.P.M.S. Neves ◽  
Augusto C. Tomé ◽  
José A.S. Cavaleiro
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Structural Characterization ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Tandem Mass ◽  
Aryl Ring ◽  
Esi Ms ◽  
Product Ions

meso-tetraarylporphyrins with different substituents linked either to an aryl ring or to a β-pyrrolic position were studied by Electrospray (ESI) Tandem Mass Spectrometry (MS/MS). The electrospray mass spectra (ESI-MS) of meso-tetraarylporphyrins show the molecular ions and no significant fragmentation is noted. Structural information can be obtained by inducing fragmentation of the ions generated under ESI conditions. The product ions formed and registered in the tandem mass spectra (ESI-MS/MS) are characteristic of the chemical structure of the groups linked to the porphyrin and depend on their location. Also, the same functional group linked either to the aryl ring or to the β-pyrrolic position yields different product ions that confirm their position. Taking into consideration the Portugal-Spain special issue of the Journal of Porphyrins and Phthalocyanines, in this highlight we analyze the work done at the University of Aveiro related to the use of mass spectrometry in the structural characterization of meso-tetraarylporphyrins with carbohydrate, nitro and amino acid groups.

Unrestrictive protein modification localization and quality control for open search of mass spectra

2018 ◽  
Author(s):  
Zhiwu An ◽  
Fuzhou Gong ◽  
Yan Fu
Keyword(s):  
Mass Spectrometry ◽  
Quality Control ◽  
Tandem Mass Spectrometry ◽  
Mass Spectra ◽  
Protein Modification ◽  
Software Tool ◽  
Tandem Mass ◽  
Simulation Data ◽  
Post Translational Modifications

We have developed PTMiner, a first software tool for automated, confident filtering, localization and annotation of protein post-translational modifications identified by open (mass-tolerant) search of large tandem mass spectrometry datasets. The performance of the software was validated on carefully designed simulation data. <br>

scholarly journals Isotopologue distributions of peptide product ions by tandem mass spectrometry: Quantitation of low levels of deuterium incorporation

2007 ◽  
Vol 367 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Benlian Wang ◽  
Gang Sun ◽  
David R. Anderson ◽  
Minghong Jia ◽  
Stephen Previs ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Tandem Mass ◽  
Deuterium Incorporation ◽  
Product Ions ◽  
Low Levels ◽  
Peptide Product
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