Spin dynamics in the carbon-13 nuclear magnetic resonance spectrometric analysis of coal by cross polarization and magic-angle spinning

A detailed relaxation study has been carried out on an eastern bituminous coal from the Powhatan No. 5 mine. Emphasis is on the relaxation parameters that determine the analytical reliability of /sup 13/C CP/MAS experiments. The apparent aromaticity obtained with a contact time of 1 ms is in agreement with the value obtained from a Bloch-decay experiment. The efficiency of the /sup 13/C CP/MAS analysis of coal is discussed, including consideration of low-temperature work.