Metastable Dissociation of CH5+ Ions in the Methane Mass Spectrum

1969 ◽  
Vol 24 (12) ◽  
pp. 1959-1963
Author(s):  
I Mastan ◽  
V Mercea
Keyword(s):  
Mass Spectrum ◽  
Mass Spectrometer ◽  
Cross Sections ◽  
Mass Spectrometric ◽  
Collision Induced Dissociation ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Pass Through ◽  
Straight Lines

AbstractThe main dissociation channels of the CH5+ ion, i. e. have been investigated by a mass spectrometric method. The pressure dependences of the ratios I14,90/I17 and I13,26/I17, in the range from 4,4·10-4 to 1·10-4 Torr, were plotted. The two ratios depend linearly on the pressure in the mass spectrometer analyzer. Since the two straight lines do not pass through the origine the conclusion is drawn that, for both dissociation channels of the CH5+ ion, besides the collision-induced transitions, spontaneous transitions, i. e. pure metastable transitions, take place. The spontaneous dissociations constants (λ1 = 7,5·105 sec-1 , λ2 = 5,2·104 sec-1) and collision-induced dissociation cross-sections (σ1 = 5,25 · 10-16 cm2 , σ2 = 3,2·10-16 cm2) have been estimated. These results are discussed and compared with those reported by other authors.

scholarly journals Mass Spectrometric Calibration Procedure for Real-Time Detection of Lighter Hydrocarbons

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2123
Author(s):  
Makuachukwu F. Mbaegbu ◽  
Puspa L. Adhikari ◽  
Ipsita Gupta ◽  
Mathew Rowe
Keyword(s):  
Real Time ◽  
Mass Spectrometer ◽  
Calibration Procedure ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Selection ◽  
Mass Spectrometric Method ◽  
Mass Spectrometers ◽  
Drilling Rig

Determining gas compositions from live well fluids on a drilling rig is critical for real time formation evaluation. Development and utilization of a reliable mass spectrometric method to accurately characterize these live well fluids are always challenging due to lack of a robust and effectively selective instrument and procedure. The methods currently utilized need better calibration for the characterization of light hydrocarbons (C1–C6) at lower concentrations. The primary goal of this research is to develop and optimize a powerful and reliable analytical method to characterize live well fluid using a quadruple mass spectrometer (MS). The mass spectrometers currently being used in the field have issues with detection, spectra deconvolution, and quantification of analytes at lower concentrations (10–500 ppm), particularly for the lighter (<30 m/z) hydrocarbons. The objectives of the present study are thus to identify the detection issues, develop and optimize a better method, calibrate and QA/QC the MS, and validate the MS method in lab settings. In this study, we used two mass spectrometers to develop a selective and precise method to quantitatively analyze low level lighter analytes (C1–C6 hydrocarbons) with masses <75 m/z at concentrations 10–500 ppm. Our results suggest that proper mass selection like using base peaks with m/z 15, 26, 41, 43, 73, and 87, respectively, for methane, ethane, propane, butane, pentane, and hexane can help detect and accurately quantify hydrocarbons from gas streams. This optimized method in quadrupole mass spectrometer (QMS) will be invaluable for early characterization of the fluid components from a live hydrocarbon well in the field in real time.

AN ELECTRON IMPACT STUDY OF CHLOROMETHYL AND DICHLOROMETHYL DERIVATIVES

1962 ◽  
Vol 40 (9) ◽  
pp. 1730-1737 ◽  
Author(s):  
A. G. Harrison ◽  
T. W. Shannon
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Methyl Chloride ◽  
Heat Of Formation ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Impact Study ◽  
Kcal Mole ◽  
Appearance Potential

The appearance potential of the CH2Cl+ ion has been measured from methyl chloride, dichloromethane, bromochloromethane, and ethyl chloride. The results lead to ΔHf(CH2Cl+) = 230 ± 3 kcal/mole. The heat of formation of CHCl2+ is estimated to be 215 ± 3 kcal/mole from the appearance potential of this ion in the mass spectrum of chloroform and of bromodichloromethane. By the indirect mass spectrometric method ΔHf(CH2Cl) = 29 ± 3 kcal/mole and ΔHf(CHCl2) = 15 ± 3 kcal/mole are obtained. The ionization potentials of a number of chlorine-containing compounds have been measured.

Mass Spectrometric Identification of 2-Mercaptobenzothiazole Sulfenamide Accelerators in Rubber Vulcanizates

1973 ◽  
Vol 46 (4) ◽  
pp. 1035-1043 ◽  
Author(s):  
A. S. Hilton ◽  
A. G. Altenau
Keyword(s):  
Mass Spectrum ◽  
Solvent Extraction ◽  
Sample Preparation ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Sample Tube ◽  
Fragment Ions ◽  
Amine Fragment ◽  
Mass Spectrometric Identification

Abstract The identification of accelerators in rubber vulcanizates has traditionally been a difficult and tedious task. The mass spectrometric method described in this paper offers a simple and expedient approach to the identification of 2-mercaptobenzothiazole sulfenamides. Neither complicated sample preparation nor solvent extraction of the vulcanizates is required as in the more common methods employed. Only about one-half gram of vulcanizate is needed for the analysis. The sample tube is attached to the mass spectrometer, heated for 15–20 min at 150–200° C and then the mass spectrum of the volatiles is recorded. The characteristic amine fragment ions are utilized for identification of the amine portion while the presence of benzothiazole is indicated by a peak at m/e=135. Spectra obtained from analysis of seven vulcanizates containing different accelerators are presented and the results discussed. The identification of the accelerator in a competitor's tread is also discussed.

scholarly journals ZOOHYGIENIC CHARACTERISTICS OF BIOTECHNOLOGICAL METHODS OF METABOLISM REGULATING OF CHICKENS EMBRYO IN THE PROCESS OF INCUBATION

2020 ◽  
pp. 100-105
Author(s):  
Olga Bordunova ◽  
Evgeniya Samokhina ◽  
Leontiі Khmelnychyi ◽  
Mykola Povod ◽  
Victoria Vechorka
Keyword(s):  
Mass Spectrometer ◽  
Gas Permeability ◽  
Experimental Studies ◽  
Mass Spectrometric ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Hatching Eggs ◽  
Active Substances

The research presents the results of experimental studies of the influence of various physicochemical factors (phonophoresis, electrophoresis, electrospray, diffusion, etc.) on the rate of transport of biologically active substances through the protective layer of hatchig eggs shell of crossbred Haysex Brown. The aim of the study was to compare the effectiveness of the use of physicochemical methods of transportation of biologically active substances through the shell of hatching eggs of chickens. For the experiment, three batches of eggs were formed, which were obtained from layer hens Haysex Brown, 144 pieces in each experimental group. The kinetic parameters of BAS transport through bioceramic protective barriers of eggs were calculated based on the determination of BAS concentration on the surface and inside the egg by mass spectrometric method (mass spectrometer with ionization of 252Cf fission fragments "MSBH", (Ltd "SELMI", Sumy, Ukraine). The degree of permeability of bioceramic layers of the shell relative to the model gas mixture which is identical to the atmospheric air was studied by the method of V. Breslavets et other and the mass spectrometric method (gas mass spectrometer "MX 7304A"). Electron microscopic studies were performed on a scanning electron microscope REMMA-102; Visilog 6.11 (Noesis, Belgium) was used to process the obtained digital images to determine the number of shell microdefects per unit area of the digital image. It has been experimentally proved that to increase the efficiency of transport of biologically active substances (BAS) through the bioceramic layers of the shell of hatching eggs of Loman Brown hens, it is advisable to use ultrasonic treatment (phonophoresis, sonophoresis), substances - enhancers, including plant terpenes (L-menthol), DMSO and cyclodextrin. Phonophoretic treatment of hatching eggs increases the hatchability of eggs by 7.6%. At the same time, the gas permeability of the bioceramic layer increases significantly (by 0.43. 10-4 m3 / m2 s).

scholarly journals ZOOHYGIENIC CHARACTERISTICS OF BIOTECHNOLOGICAL METHODS OF METABOLISM REGULATING OF CHICKENS EMBRYO IN THE PROCESS OF INCUBATION

2021 ◽  
pp. 36-41
Author(s):  
Olga Bordunova ◽  
Evgeniya Samokhina ◽  
Leontiy Khmelnychyi ◽  
Mykola Povod ◽  
Victoria Vechorka
Keyword(s):  
Mass Spectrometer ◽  
Gas Permeability ◽  
Experimental Studies ◽  
Mass Spectrometric ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Hatching Eggs ◽  
Active Substances

  The research presents the results of experimental studies of the influence of various physicochemical factors (phonophoresis, electrophoresis, electrospray, diffusion, etc.) on the rate of transport of biologically active substances through the protective layer of hatching eggs shell of crossbred Haysex Brown. The aim of the study was to compare the effectiveness of the use of physicochemical methods of transportation of biologically active substances through the shell of hatching eggs of chickens. For the experiment, three batches of eggs were formed, which were obtained from layer hens Haysex Brown, 144 pieces in each experimental group. The kinetic parameters of BAS transport through bioceramic protective barriers of eggs were calculated based on the determination of BAS concentration on the surface and inside the egg by mass spectrometric method (mass spectrometer with ionization of 252Cf fission fragments "MSBH", (Ltd "SELMI", Sumy, Ukraine). The degree of permeability of bioceramic layers of the shell relative to the model gas mixture which is identical to the atmospheric air was studied by the method of V. Breslavets et other and the mass spectrometric method (gas mass spectrometer "MX 7304A"). Electron microscopic studies were performed on a scanning electron microscope REMMA-102; Visilog 6.11 (Noesis, Belgium) was used to process the obtained digital images to determine the number of shell microdefects per unit area of the digital image. It has been experimentally proved that to increase the efficiency of transport of biologically active substances (BAS) through the bioceramic layers of the shell of hatching eggs of Loman Brown hens, it is advisable to use ultrasonic treatment (phonophoresis, sonophoresis), substances - enhancers, including plant terpenes (L-menthol), DMSO and cyclodextrin. Phonophoretic treatment of hatching eggs increases the hatchability of eggs by 7.6%. At the same time, the gas permeability of the bioceramic layer increases significantly (by 0.43. 10-4 m3 / m2 s).

Cross-section measurements of 6Li, 7Li, 9Be, 10Be, 10B, 11B formed by spallation reactions induced by protons in the energy range 150 MeV to 19 GeV in oxygen targets

1968 ◽  
Vol 46 (10) ◽  
pp. S557-S560 ◽  
Author(s):  
F. Yiou ◽  
J. Dufaure de Citres ◽  
F. Frehel ◽  
E. Gradsztajn ◽  
R. Bernas
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Cosmic Ray ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Spallation Reactions

The determination of Li, Be, and B cross sections formed by spallation reactions induced by high-energy protons in C, N, and O targets is of interest for cosmic-ray physics and astrophysics. A mass-spectrometric method has been devised to measure the stable and long-lived isotopes 6Li, 7Li, 9Be, 10Be (τ = 2.5 × 106 yr), 7Be (τ = 54 d), 10B, 11B, formed in oxygen for proton energies of 0.15, 0.60, and 19 GeV. These results have been included in a program of calculations allowing us to determine the quantity of matter traversed by galactic cosmic rays of energy > 1.5 GeV/nucleon; the observed relative abundances are best fitted, in the slab approximation, by passage through 5.4 ± 1 g/cm2 of hydrogen.

Tandem Mass Spectrometric Evaluation of Core Structures of Aromatic Compounds after Catalytic Deoxygenation

2017 ◽  
Author(s):  
Xueming Dong
Keyword(s):  
Aromatic Compounds ◽  
Supported Catalyst ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Aromatic Rings ◽  
Tandem Mass Spectrometric ◽  
Catalytic Deoxygenation ◽  
Oxygen Atoms

Catalytic deoxygenation of coal enhances the stability and combustion performance of coal-derived liquids. However, determination of the selectivity of removal of oxygen atoms incorporated in or residing outside of aromatic rings is challenging. This limits the ability to evaluate the success of catalytic deoxygenation processes. A mass spectrometric method, in-source collision-activated dissociation (ISCAD), combined with high resolution product ion detection, is demonstrated to allow the determination of whether the oxygen atoms in aromatic compounds reside outside of aromatic rings or are part of the aromatic system, because alkyl chains can be removed from aromatic cores via ISCAD. Application of this method for the analysis of a subbituminous coal treated using a supported catalyst revealed that the catalytic treatment reduced the number of oxygen-containing heteroaromatic rings but not the number of oxygen atoms residing outside the aromatic rings.<br>

Tandem Mass Spectrometric Evaluation of Core Structures of Aromatic Compounds after Catalytic Deoxygenation

2017 ◽  
Author(s):  
Xueming Dong
Keyword(s):  
Aromatic Compounds ◽  
Supported Catalyst ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Aromatic Rings ◽  
Tandem Mass Spectrometric ◽  
Catalytic Deoxygenation ◽  
Oxygen Atoms

Catalytic deoxygenation of coal enhances the stability and combustion performance of coal-derived liquids. However, determination of the selectivity of removal of oxygen atoms incorporated in or residing outside of aromatic rings is challenging. This limits the ability to evaluate the success of catalytic deoxygenation processes. A mass spectrometric method, in-source collision-activated dissociation (ISCAD), combined with high resolution product ion detection, is demonstrated to allow the determination of whether the oxygen atoms in aromatic compounds reside outside of aromatic rings or are part of the aromatic system, because alkyl chains can be removed from aromatic cores via ISCAD. Application of this method for the analysis of a subbituminous coal treated using a supported catalyst revealed that the catalytic treatment reduced the number of oxygen-containing heteroaromatic rings but not the number of oxygen atoms residing outside the aromatic rings.<br>

Sign in / Sign up

Export Citation Format

Share Document