Analysis of doubly-charged ion reactions and consecutive two-step degradation processes by means of metastable peak mapping

Fraefel, A.; Seibl, J.

doi:10.1016/0020-7381(83)85010-4

Cited by 7 publications

(2 citation statements)

References 19 publications

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“…The current approach is related to methods originally developed for the automated mapping of metastable ions produced in the field-free regions of magnetic sector instruments . The mapping was originally done by fast magnetic field scanning while the electric sector field was stepped in small intervals − or, alternatively, by fast electric field scanning combined with slow magnetic sector field scanning. , These early attempts recognized the unique capabilities of the product ion mapping for the characterization of complex mixtures, but they did not permit accurate precursor ion selection and accurate product ion mass assignment due to the ion optics limitations of the linked scans. , The current work presents an advancement over the early metastable ion mapping methods by using the double-focusing properties of the magnetic sector (MS-1) to accurately select precursor ions and the oa-TOF (MS-2) to acquire product ion spectra with better that unit mass resolution. The routine application of the approach and typical results obtained from the analysis of representative petroleum systems are presented below.…”

Section: Resultsmentioning

confidence: 99%

Automated Tandem Mass Spectrometry by Orthogonal Acceleration TOF Data Acquisition and Simultaneous Magnet Scanning for the Characterization of Petroleum Mixtures

Roussis

2001

Anal. Chem.

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The automated acquisition of the product ion spectra of all precursor ions in a selected mass range by using a magnetic sector/orthogonal acceleration time-of-flight (oa-TOF) tandem mass spectrometer for the characterization of complex petroleum mixtures is reported. Product ion spectra are obtained by rapid oa-TOF data acquisition and simultaneous scanning of the magnet. An analog signal generator is used for the scanning of the magnet. Slow magnet scanning rates permit the accurate profiling of precursor ion peaks and the acquisition of product ion spectra for all isobaric ion species. The ability of the instrument to perform both high- and low-energy collisional activation experiments provides access to a large number of dissociation pathways useful for the characterization of precursor ions. Examples are given that illustrate the capability of the method for the characterization of representative petroleum mixtures. The structural information obtained by the automated MS/MS experiment is used in combination with high-resolution accurate mass measurement results to characterize unknown components in a polar extract of a refinery product. The exhaustive mapping of all precursor ions in representative naphtha and middle-distillate fractions is presented. Sets of isobaric ion species are separated and their structures are identified by interpretation from first principles or by comparison with standard 70-eV EI libraries of spectra. The utility of the method increases with the complexity of the samples.

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Section: Resultsmentioning

confidence: 99%

Automated Tandem Mass Spectrometry by Orthogonal Acceleration TOF Data Acquisition and Simultaneous Magnet Scanning for the Characterization of Petroleum Mixtures

Roussis

2001

Anal. Chem.

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“…The study of multiply-charged ions 1,2 has always been a subject of interest in mass spectrometry, since it can give information about ion structures, through the measurement of the kinetic energy released upon charge separation reactions. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] The first example presented in the literature 6 refers to the fragmentation of the doubly-charged benzene molecular ion, where the kinetic energy (2.8 eV), released in the reaction C 6 H 6 2+ → C 5 H 5 + CH 3 + , corresponds to an intercharge distance of 5.14 Å. This distance is considerably larger than the one expected for a cyclic structure (2.8 Å), providing a strong indication for a linear configuration for the transition state.…”

Section: Introductionmentioning

confidence: 99%

Fragmentation reactions of molecular ions and dications of indoleamines

Cardoso

Correia

1999

Eur. J. Mass Spectrom.

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The combination of techniques such as two-dimensional mass spectrometry and mass analysed ion kinetic energy spectrometry (with and without collision gas) in the study of gas-phase ion chemistry of indole, gramine, tryptamine and serotonine enabled us to establish the fragmentation pathways of their singly-and doubly-charged molecular ions generated by electron impact. The measurement of the kinetic energy released in the charge separation reactions of the molecular dications produced information on the intercharge distance on the transition state for the fragmentation, assuming that it arises entirely from the coulombic energy released. For the singly-charged molecular ions of indoleamines, loss of the neutral molecule CH 2 =NR (R = H or CH 3), by hydrogen transfer from the amino (or methyl) group to the indole nucleus, is the only fragmentation occurring in the third field-free region of the mass spectrometer. Upon collision of the molecular ion with He gas, a competing process of bond cleavage by loss of the radical • CH 2 NH 2 (or • N(CH 3) 2 for gramine) is observed for tryptamine and serotonine. The doubly-charged ions dissociate by elimination of neutral molecules or radicals to generate doubly-charged fragment ions or by charge separation reactions. The intercharge distance, calculated from the kinetic energy released in the fragmentation, was, whenever possible, correlated with charge location in the ion.

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Selective analysis of metastable ions

Fraefel¹,

Seibl²

1985

Mass Spectrometry Reviews

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Analysis of doubly-charged ion reactions and consecutive two-step degradation processes by means of metastable peak mapping

Cited by 7 publications

References 19 publications

Automated Tandem Mass Spectrometry by Orthogonal Acceleration TOF Data Acquisition and Simultaneous Magnet Scanning for the Characterization of Petroleum Mixtures

Automated Tandem Mass Spectrometry by Orthogonal Acceleration TOF Data Acquisition and Simultaneous Magnet Scanning for the Characterization of Petroleum Mixtures

Fragmentation reactions of molecular ions and dications of indoleamines

Selective analysis of metastable ions

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