Effect of metastable ions on the formation of mass of spectra of a magnetic instrument with single focusing

The mass spectra of representative series of simple alkyl acetoacetates, alkyl acetothioacetates, and some unsaturated esters derived from unsaturated alcohols or phenols are reported and discussed. The fragmentation schemes have been established by high resolution measurements, appropriate metastable ions, and by deuterium and 18O labelling. Many of the spectra show significant skeletal rearrangement fragments arising from either loss of carbon monoxide or carbon dioxide.

Download Full-text

Translational energy release and stereochemistry of steroids. VIII-The mechanism of the elimination of water from metastable ions in epimeric 3-hydroxy steroids of the 5α-series

Organic Mass Spectrometry ◽

10.1002/oms.1210230605 ◽

1988 ◽

Vol 23 (6) ◽

pp. 453-459 ◽

Cited By ~ 11

Author(s):

Z. V. I. Zaretskii ◽

J. M. Curtis ◽

A. G. Brenton ◽

J. H. Beynon ◽

Carl Djerassi

Keyword(s):

Energy Release ◽

Translational Energy ◽

Metastable Ions

Download Full-text

Lifetime of heliumlike metastable ions measured

Physics Today ◽

10.1063/1.3022618 ◽

1971 ◽

Vol 24 (3) ◽

pp. 19-19

Author(s):

John T. Scott

Keyword(s):

Metastable Ions

Download Full-text

Metastable ions derived from triethylamine and benzylamine: Electron impact ionization compared to infrared multiple-photon dissociation

Chemical Physics Letters ◽

10.1016/0009-2614(83)80530-2 ◽

1983 ◽

Vol 97 (4-5) ◽

pp. 467-470 ◽

Cited By ~ 1

Author(s):

Yehuda Haas ◽

Chava Lifshitz

Keyword(s):

Electron Impact ◽

Impact Ionization ◽

Electron Impact Ionization ◽

Infrared Multiple Photon Dissociation ◽

Metastable Ions

Download Full-text

Detection of Metastable Ions With the Mass Spectrometer

Selected Scientific Papers of E.U. Condon ◽

10.1007/978-1-4613-9083-1_36 ◽

1991 ◽

pp. 496-498

Author(s):

J. A. Hipple ◽

E. U. Condon

Keyword(s):

Mass Spectrometer ◽

Metastable Ions

Download Full-text

EVOLUTION OF VIEWS ON THE DEVELOPMENT AND IMPLEMENTATION OF MODERN SURGICAL MAGNETIC INSTRUMENTS ON THE CASE OF INFLAMMATORY PENETRATING INJURIES OF THE BREAST

Kharkiv Surgical School ◽

10.37699/2308-7005.2.2020.23 ◽

2020 ◽

pp. 113-118

Author(s):

Yu. V. Bunin ◽

P. M. Zamyatin ◽

R. M. Mihаylusov ◽

V. V. Negoduyko ◽

S. O. Beresnyev ◽

...

Keyword(s):

Foreign Bodies ◽

Pleural Cavity ◽

Gunshot Wounds ◽

Surgical Instruments ◽

Internal Organs ◽

Surgical Interventions ◽

Magnetic Nozzle ◽

Endoscopic Laser ◽

Laser Visualization ◽

Magnetic Instrument

Summary. The arms — to analyze the evolution of the development of modern surgical instruments in gunshot wounds chest. Materials and methods. 80 cases of using a modern magnetic surgical instrument for penetrating gunshot wounds of the chest were analyzed. Intraoperatively used: a magnetic multifunctional tool for the diagnosis and removal of metallic ferromagnetic foreign bodies, a flexible device for removing ferromagnetic foreign bodies, a magnetic tool for endovideoscopic diagnosis and removal of metallic ferromagnetic foreign bodies from the abdominal and pleural cavities, a magnetic nozzle for video endoscopic surgical interventions. When removing metal foreign bodies, the following methods were used: a method for preliminary determination of the material and properties of a foreign body, a method for video endoscopic laser visualization of the internal organs of the abdominal and pleural cavities. Results. Foreign bodies of the pleural cavity were diagnosed in 80 (100 %) wounded according to СT. Ferromagnetic metal foreign bodies of a gunshot origin of the pleural cavity were removed both during thoracotomy or minithoracotomy, and during thoracoscopic surgical interventions using the method of video endoscopic laser visualization of the internal organs of the abdominal and pleural cavities. The most convenient tool was the endoscopic magnetic tool for removing foreign bodies from the pleural or abdominal cavities. A magnetic nozzle for video endoscopic surgical interventions allows navigation both in the pleural cavity and along the wound channel. Conclusions. 1. The development of a surgical magnetic instrument was phased and began with the improvement of a surgical magnetic instrument to remove ferromagnetic foreign bodies of soft tissues. 2. The improvement of the tool took place as the restrictions on the use of the existing tool were established, which was a prerequisite for the development of a new tool. 3. It is advisable to create a special set of surgical magnetic instruments for video endoscopic surgery.

Download Full-text

Metastable Ions as a Guide to Reaction Mechanisms. Loss of ’OH from Substituted Nitrobenzene Molecular Ions

Zeitschrift für Naturforschung A ◽

10.1515/zna-1974-0323 ◽

1974 ◽

Vol 29 (3) ◽

pp. 507-512

Author(s):

T. Keough ◽

J. H. Beynon ◽

R. G. Cooks ◽

C. Chang ◽

R. H. Shapiro

Keyword(s):

Nitro Group ◽

Hydrogen Transfer ◽

Direct Interaction ◽

Kinetic Energy Release ◽

Molecular Ions ◽

Time Range ◽

Direct Role ◽

Ion Fragmentation ◽

Distinct Process ◽

Metastable Ions

Loss of ‘OH from the molecular ions of nitrobenzenes having various substituents in the m- and p-positions does not involve substituent randomization and reaction through the ortho-isomer; the kinetic energy release accompanying metastable ion fragmentation shows this latter to be an entirely distinct process. The origin of the hydrogen lost as 'OH in the m- and p-compounds is the ring (mainly the position ortho to the nitro group in methyl p-nitrobenzoate). However, the hydrogens of the substituent do play a direct role in the reaction as shown by an isotope effect upon the abundances of metastable peaks. Hydrogen atom abstraction by the ionized nitro group apparently occurs independently of participation by the substituent on the nitrobenzene but a second hydrogen transfer from this substituent to the ring precedes fragmentation. Direct interaction between groups o ' the aromatic ring that are not ortho to each other therefore apparently does not occur. Inversion of the rate constants for two reactions, NO' loss and CH2O loss from the methyl p-nitrobenzoate molecular ion in the metastable ion time range, has been observed following isotopic substitution.

Download Full-text