Selected reviews on mass spectrometric topics. XXVII. Reactions in the ion source prior to ionization

1989 ◽  
Vol 8 (1) ◽  
pp. 57-57
Author(s):  
H. Budzikiewicz
Keyword(s):  
Ion Source ◽  
Mass Spectrometric

Cyclopentadienylidenecarbonyl: the Major Primary Thermolytic Fragment of Salicylaldehyde

1971 ◽  
Vol 49 (22) ◽  
pp. 3602-3606 ◽  
Author(s):  
O. A. Mamer
Keyword(s):  
Temperature Dependence ◽  
Title Compound ◽  
Molecular Ions ◽  
Ion Source ◽  
Mass Spectrometric ◽  
Thermal Reactor ◽  
Helium Flow ◽  
Preparative Scale ◽  
Thermal Fragmentation ◽  
Chromatographic Mass

The thermal fragmentation of salicylaldehyde was studied from two aspects. Firstly, the temperature dependence of the intensity of the thermolytic fragment molecular ions was observed at 11 eV in the effluent from a helium flow thermal reactor attached through a helium separator to the ion source of a mass spectrometer. Secondly, the products of the thermolysis on a semi-preparative scale under trapping conditions were determined by coupled gas chromatographic – mass spectrometric analysis.The title compound is the major primary thermal fragment in this study and was trapped with methanol as carboxymethylcyclopentadiene.

Reaction of C60with Epihydrin and Epichloro(Bromo)Hydrin in a Mass Spectrometric Ion Source

1993 ◽  
Vol 1 (4) ◽  
pp. 475-479 ◽  
Author(s):  
Zhizhong Jing ◽  
Meilan Wang ◽  
Xungao Zhang ◽  
Ling Zhu ◽  
Rongsheng Sheng ◽  
...  
Keyword(s):  
Ion Source ◽  
Mass Spectrometric

Gas-Liquid Chromatography and Mass Spectrometric Ion Selective Detection of Sterigmatocystin in Grains

1976 ◽  
Vol 59 (5) ◽  
pp. 1037-1044
Author(s):  
Abdulazim S Salhab ◽  
Gerald F Russell ◽  
James R Coughlin ◽  
Dennis P H Hsieh
Keyword(s):  
Gel Permeation Chromatography ◽  
Great Difficulty ◽  
Ion Source ◽  
Mass Spectrometric ◽  
Gas Liquid Chromatography ◽  
Mass Fragmentography ◽  
Selective Ion Monitoring ◽  
Silicone Liquid ◽  
Liquid Chromatographic ◽  
Short Glass

Abstract A method was developed for direct gas-liquid chromatographic-mass spectrometric (GLC-MS) analysis of nonderivatized sterigmatocystin in wheat, rice, barley, and corn. Sterigmatocystin was extracted from spiked grain samples by 2 methods, both of which yielded high recoveries of 14C-labeled sterigmatocystin (>90%). Extracts were cleaned up by gel permeation chromatography on polystyrene with tetrahydrofuran as the eluant. Chromatography of relabeled compound indicated good recoveries (>90%). The GLC-MS system was modified to give an all-glass chromatographic pathway to the ion source. Short glass or quartz columns packed with silicone liquid phase on inert supports gave the best results. Trace levels of sterigmatocystin were very labile in all gas chromatographic systems and levels below 5 ppb in grains were detected only with great difficulty. The GLC-MS system was utilized in the mass fragmentography mode, with selective ion monitoring of the m/e 295, 306, and 324 peaks. These ions were present in only trace levels in all control grain samples, indicating minimal interference from other compounds. The limit of accurate detectability (20 ng) on spiked grain samples was lower than previously reported. Lower levels of sterigmatocystin (1 ppb or 4 ng on column) could be detected in grains by using the mass fragmentography mode, but these levels could not be measured accurately.

Massenspektrometrische Untersuchungen an α,α’-Bis-acetylen-ketonen / Mass Spectrometric Investigations with α,α’-Bis-acetylenic ketones

1971 ◽  
Vol 26 (10) ◽  
pp. 1003-1007 ◽  
Author(s):  
Eugen Müller ◽  
Adolph Segnitz ◽  
Klaus-Peter Zeller
Keyword(s):  
Carbon Monoxide ◽  
Mass Spectrometer ◽  
Ion Source ◽  
Mass Spectrometric

In the ion source of a mass spectrometer α,α’-bis-acetylenic ketones rearrange by elimination of carbon monoxide giving diyne-ion radicals.

Solvation of Cl− and O2− with H2O, CH3OH, and CH3CN in the gas phase

1973 ◽  
Vol 51 (15) ◽  
pp. 2507-2511 ◽  
Author(s):  
R. Yamdagni ◽  
J. D. Payzant ◽  
P. Kebarle
Keyword(s):  
High Pressure ◽  
Temperature Dependence ◽  
Gas Phase ◽  
Experimental Technique ◽  
Equilibrium Constants ◽  
Ion Source ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Free Energies

Determination of the temperature dependence of the equilibrium constants Kn,n−1 for the reactions A −Bn = A −Bn−1 + B where A− equals Cl− and O2− and B is HOH, CH3OH, or CH3CN leads to the corresponding ΔH0n−1, ΔG0n−1,n, and ΔS0n−1,n values. The experimental technique is based on mass spectrometric detection of ions escaping from a high pressure ion source. At n = 1, Cl− is solvated most strongly by methanol, then CH3CN and HOH. At higher n a cross over is observed with water becoming the best solvent. These results are in agreement with the positive transfer enthalpies and free energies for Cl− from the liquid solvents HOH → CH3OH and HOH → CH3CN reported in the literature.O2− is solvated more strongly than Cl− appearing thus as an ion of "size" intermediate between Cl− and F− Again CH3OH gives the highest interaction for n = 1, however for n > 1 water gives stronger interactions.

Mass-spectrometric ion source for high-temperature investigations

1971 ◽  
Vol 10 (1) ◽  
pp. 82-83
Author(s):  
V. V. Fesenko ◽  
S. P. Gordienko ◽  
A. A. Lysenko
Keyword(s):  
High Temperature ◽  
Ion Source ◽  
Mass Spectrometric
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