Carbon aromaticities for a selection of 19 bituminous coals and vitrin
ite concentrates have been obtained by solid-state C-13 n.m.r. using t
he inherently quantitative single pulse excitation technique. Within e
xperimental error, the aromaticity values in the range 0.75-0.90 corre
late extremely well with the H/C ratios (R(2) = 0.93); the 11 samples
investigated with H/C ratios between 0.74 and 0.77 all have aromaticit
ies in the range 0.75-0.81. Furthermore, the correlation holds for the
coals investigated with high inertinite contents.