Gas emissions from titanium-metalloid compounds (titanium nitride and oxide) have been investigated to understand the effects of a microwave field on chemical reactions. We employed a high vacuum system (P(O2) = 10(-6) Pa) to observe in situ reductions. For titanium oxides, H-field heating significantly differed from conventional one in terms of oxygen emissions. For titanium nitride, the emissions were also induced by microwave heating. These tendencies were observed at temperatures above 1000 degrees C. A quantum chemical interpretation is provided to explain the emissions of the gases, and the experimental data is in good agreement with results predicted using the electronic energy band structure. (C) 2011 Elsevier B.V. All rights reserved.