Temperature-resolved molecular emission spectroscopy is described as a thermal analysis method for the analysis of solids and liquids. The technique uses an electrically heated graphite cup to decompose and/or vaporize the sample. The vapors are carried by a stream of argon into a cool hydrogen diffusion flame. Both the quantity and the nature of the decomposed species can be determined. The technique is particularly useful for the determination of sulfur, phosphorus, or nitrogen. Calibration curves for sulfur show the expected parabolic shape, and those for phosphorus are linear. The detection limit for elemental sulfur was determined to be approximately 50 ng. The evolution of sulfur is shown to be related to the decomposition temperature which is characteristic of the sulfur-containing species. Reproducibility of the decomposition temperatures is typically ±2%.