The intensity of gas-phase species present in a graphite furnace/dilatometer from room temperature to 1400degreesC were recorded by a mass spectrometer in real time. Based on the relative intensities and fragmentation factors, the species could be assigned to carbon dioxide, carbon monoxide, oxygen, water, and cyanogen. At low temperature, carbon dioxide was the main species observed whereas at high temperature, carbon monoxide was the predominant compound. The appearance of these species at low and high temperature was consistent with the results of equilibrium calculations for the coupled reactions of C+O-2=CO2 and CO2+C=2CO. The intensity data from the mass spectrometer indicate that trace oxygen reacts with the graphite to form the carbon dioxide and carbon monoxide.