Evolved gas analyses of model inorganic compounds and apatites are described. The measurements are performed on the system - a 'thermochromatograph' (ThGC) - with a low-volume, thermal furnace, interfaced to a capillary gas chromatograph (GC) via a computer-controlled, pneumatic sample inlet device in the 70-600 degrees C region. The 'information content' performance of this inherently simpler system is comparable to that of TG/GC/MS and TG/GC/IR systems when similar materials are analyzed.