Thermogravimetric analysis for boiling points and vapour pressure

A TGA instrument has been adapted for rapid measurement of boiling points and vapour pressure at temperatures from ambient up to 400 degrees C and pressures from ambient down to 20 mm Hg. Samples were contained in sealed holders having a laser-drilled aperture. Several organic liquids in the 100 to 300 g MW range showed good agreement with reference vapour pressure data. Sample mass, heating rate, and use of inert diluents were important variables affecting accuracy of vapour pressure measurements.