Determination of the fraction of organic carbon observable in coals and coal derivatives measured by high-resolution solid-state carbon-13 nuclear magnetic resonance spectrometry

Journal Article · Sat Feb 01 04:00:00 EST 1986 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac00293a028· OSTI ID:6274116

Hagaman, E W; Chambers, Jr, R R; Woody, M C

The aromatic carbon fractions of coals, f/sub a/, calculated by fitting integrated intensity data from cross polarization/magic angle spinning TC nuclear magnetic resonance spectra of coals to an expression that describes the magnetization behavior at long cross polarization times, t/sub cp/, and f/sub a/ determined from a single spectrum recorded with t/sub cp/ = 1 ms show good agreement. This indicates that in single spectrum analysis, a 1 ms cross polarization contact time is a judicious compromise value consistent with nearly complete cross polarization from all carbons that contribute to the observable magnetization and with minimum errors introduced by differential T/sub 1p/(H) for the aromatic and aliphatic resonance bands. Spin counting experiments performed using mixtures of coal and a diamagnetic standard establish that the observable carbon magnetization in several coals of widely varying rank is derived from 40 to 60% of the organic carbon in these substances. By use of a /sup 13,14/C-double-labeling experiment it is shown that in chemically modified coals, the introduced carbon and coal carbon fractions are detected discriminately and to a degree that is dependent of the type of modification the coal has undergone. 40 references, 5 figures, 7 tables.

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6274116
• Journal Information: Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 58:2; ISSN ANCHA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400103 -- Radiometric & Radiochemical Procedures-- (-1987)
400104 -- Spectral Procedures-- (-1987)
BETA DECAY RADIOISOTOPES
BETA SPECTROSCOPY
BETA-MINUS DECAY RADIOISOTOPES
CARBON
CARBON 13
CARBON 14
CARBON ISOTOPES
CARBONACEOUS MATERIALS
CHEMICAL ANALYSIS
COAL
DATA
ELEMENTS
ENERGY SOURCES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FOSSIL FUELS
FUELS
INFORMATION
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
NMR SPECTRA
NONMETALS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
QUANTITATIVE CHEMICAL ANALYSIS
RADIOISOTOPES
RELAXATION
RESONANCE
SPECTRA
SPECTROSCOPY
SPIN-LATTICE RELAXATION
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES