Application of 1H pulse n.m.r. to the determination of molecular and macromolecular phases in coals

1H n.m.r. free-induction decay (FID), after single 90 ° pulse excitation has been studied for bituminous and subbituminous coals and after saturation with deuterated pyridine and sulphuric acid. FID signals were broken down into Gaussian and Lorentzian components and their initial amplitudes determined. The ratio of hydrogen atoms occuring in the mobile phase (HMPh) and in the immobile phase (HIPh) were calculated. The ratios, HMPh:HIPh, measured in the presence of pyridine-d 5 and D 2SO 4 delimit the range where the ratio of molecules:macromolecules occuring in coals can be found. The procedure described in this Paper can be used to estimate the total content of molecules (extractable and non-extractable) occuring in coals.