DTA—TG—MS in the investigation of clays: Quantitative determination of H 2O, CO and CO 2 by evolved gas analysis with a mass spectrometer

Abstract

A thermoanalyzer (Mettler) combined with a quadrupole mass spectrometer (Balzers) by a capillary inlet system allows simultaneous DTA, TG and evolved gas analysis in different atmospheres. Decomposition of CaC 2O 4·H 2O in air and argon, respectively, demonstrates the usefulness of the mass spectrometer for the quantitative determination of H 2O, CO 2 and CO. Decomposition of NaHCO 3 at a heating rate of 10°C min −1 reveals that H 2O and CO 2 evolved simultaneously at a relatively low temperature (159°C) can also be determined quantitatively and nearly without retardation compared with the weight loss step. In the investigation of clays an example will be given of the usefulness of the described DTA—TG—MS in the quantitative interpretation of overlapping reactions.