During rapid pyrolysis of coal, TG-FTIR (thermogravimetry - Fourier transform infrared) technique can be effectively used to simultaneously detect and measure the three main O-containing gases, namely H2O, CO and CO2. Their sum corresponds to the quantitative amount of oxygen in the coal and is, in general, inherently more accurate than the 'by-difference' values. In this paper, we first attempt to relate the 'by-difference' values for %O reported for the Argonne premium coal samples (lignite to bituminous rank) (Argonne Users Handbook) to those determined from a TG-FTIR examination of the pyrolysis gases evolved. Another objective of the work is to relate the pyrolysis gases (H2O, CO and CO2) evolved to oxygen-containing functional groups found in coals as well as the evolution of these functional groups as a function of rank. Correlations are also developed between the TG-FTIR oxygen values and other parameters determined for the Argonne Premium Coals. In particular, comparisons of our results using TG-FTIR with analyses carried out by other workers on functional group analysis of acidic groups are considered. (c) 2005 Elsevier B.V. All rights reserved.