PRACTICAL ASPECTS FOR THE COUPLING OF GAS ANALYTICAL METHODS WITH THERMAL-ANALYSIS INSTRUMENTS

The coupling of mass spectrometry, Fourier-transform infrared spectros copy and gas chromatography with thermal-analysis methods is discussed from the practical point of view. The gas-flow conditions in thermoba lances, the design of coupling interfaces, and the features of the gas analysers relevant to the coupling are shown. The high sensitivity of the Skimmer coupling as compared to the capillary coupling of mass sp ectrometers is explained by the perfect gas-flow conditions and elimin ation of condensation effects. Optimisation of transfer systems and ga s cells contribute to a high sensitivity also for the FTIR coupling. T he evaporation of zinc and phosphorus from a ZnGeP2 semiconductor is s hown by the Skimmer coupling with MS and the HF evolution from a brick clay is measured by coupled FTIR. (C) 1997 Elsevier Science B.V.