Advanced NMR approaches in the characterization of coal. [Quarterly] report No. 8
The paper submitted earlier on the use of (bicyclo[3.2.1]4pyrrolidino-N-methyl-octan-8-one triflate) ({sup 13}CO-123) as a {sup 13}C intensity standard was accepted for publication. Subsequently, {sup 13}CO-321 was used in this manner for quantitative {sup 13}C CP-MAS NMR analysis (including spin counting) of Argonne Premium coals. The cross-polarization time constants, T{sub CH}, and the rotating-frame proton spin-lattice relaxation times, T{sub 1p}{sup H}, were determined for each major peak of each coal via a combination of variable contact-time and variable spin-lock (T{sub 1p}{sup H}) experiments. Two or three components of rotating-frame {sup 1}H relaxation decay and two or three components of T{sub CH} behavior were observed for each major {sup 13}C peak of each coal. These data were used to determine the number of carbon atoms detected in each coal; these values are in the range between 77% and 87% of the amount of carbon known to be in each coal from elemental analysis data, except for Pocahontas No. 3, for which only 50% of the carbon was detected. In an attempt to use {sup 1}H CRAMPS to elucidate chemical functionality in coal, pyridine-saturated samples of the Argonne Premium coals were examined in detail in terms of their {sup 1}H CRAMPS NMR spectra. These spectra were deconvoluted to yield relative concentrations for individual peaks.
- Research Organization:
- Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG22-90PC90290
- OSTI ID:
- 10109492
- Report Number(s):
- DOE/PC/90290-8; ON: DE93006009
- Resource Relation:
- Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
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