FACTORS AFFECTING THE SPECTRAL RESPONSE IN A TG FT-IR EXPERIMENT/

We discuss situations where thermogravimetric/Fourier transform infrar ed (TG/FT-IR) plots are obtained which differ substantially from the e xpected ones. The most common of these situations involves samples tha t release atmospheric components (H2O, CO2) at low temperatures. It is shown that the phenomena are mainly related to the purging action of the carrier gas, which strongly influences the spectroscopic portion o f the TG/FT-IR plot. Such an influence, as well as the different situa tions originating from it, is discussed and explained on the basis of an analogy with the operational mode of a conventional dispersive spec trometer.