Field ionization and field desorption mass spectrometry applied to coal research

Journal Article · Sat Jan 01 00:00:00 EST 1977 · Prepr. Pap. - Am. Chem. Soc., Div. Fuel Chem.; (United States)

OSTI ID:6302873

John, G A; Buttrill, S E; Anbar, M

An activated slit-type tantalum foil cathode was developed by Stanford Research Institute as a field ionization source for mass spectroscopy; this technique, coupled with computer control of the magnetic scan and of the temperature programmer for sample vaporization, prevents fragmentation of the ions produced, thus giving very accurate molecular weight profiles for complex samples, while the temperature programing distinguishes between low-molecular-weight components of the sample and pyrolysis products. The method was applied to a solvent-refined oil from a Kentucky coal and to various solvent-extracted fractions from H-Coal oil; in the latter case, all the fractions showed comparable molecular weight distributions. Application to a weathered Venezuelan crude showed a 3 to 6% standard deviation in the 250 to 550 mol wt range. A broken metal tip cathode was developed for field desorption, i.e., field ionization in the presence of a solid sample, and applied to analysis of asphaltenes from solvent-refined Kentucky coal. 11 references.

• Research Organization: Stanford Research Inst, CA
• OSTI ID: 6302873
• Journal Information: Prepr. Pap. - Am. Chem. Soc., Div. Fuel Chem.; (United States), Vol. 22:5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
ASPHALTENES
DESORPTION
MASS SPECTROSCOPY
ION SOURCES
ASPHALTS
BITUMENS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
SPECTROSCOPY
TAR
400104* - Spectral Procedures- (-1987)
010600 - Coal
Lignite
& Peat- Properties & Composition