Electron paramagnetic resonance (EPR) spectroscopy was used to analyse prop
erties of paramagnetic centres systems of the samples separated from two li
thotypes of Polish coal (85.6 wt% C). The EPR spectra of the durain samples
with a content of 2-22 vol.% exinite, 73-86 vol.% vitrinite and 5-17 vol.%
inertinite, and the clarain samples with a content of 3-14 vol.% exinite,
65-90 vol.% vitrinite and 4-32 vol.% inertinite were compared, Three differ
ent groups of paramagnetic centres in each of the coal samples were found.
The concentration of unpaired electrons and the parameters of the resonance
absorption curves: linewidths and g-factor, were determined. (C) 2000 Else
vier Science Ltd, All rights reserved.