PROGRAMMED-TEMPERATURE VAPORISER INJECTOR AS A NEW ANALYTICAL TOOL FOR COMBINED THERMAL DESORPTION PYROLYSIS OF SOLID SAMPLES - APPLICATION TO GEOCHEMICAL ANALYSIS

摘要

This paper describes a new analytical tool for the analysis of geological samples for geochemical purposes. A system is described that allows subsequent thermal treatment at several stages to occur inside the liner of a programmed temperature vaporiser injector (PTV). The samples under investigation are geological hydrocarbon source rock and coal samples. Analysis of the samples is performed in a sequential procedure. A three-step temperature-level procedure is proposed. The system described is inexpensive and easy to operate. The advantage of combining thermal desorption and pyrolysis sequentially inside a PTV injector is the flexibility of temperature selection, as well as the ease of calibration and quantitation. Moreover, the absence of a heated transfer line and heated valves minimises the risk of loss of high-molecular-mass compounds. The method described allows a detailed characterisation of oil and kerogen in a source rock. An atomic emission detector is used to monitor simultaneously the carbon and the sulphur signals for further structural elucidation of the kerogen. The results obtained with this system are in good agreement with those obtained with other pyrolysis systems.