Analysis Procedure
The samples drop from the autosampler (AS) into a purge chamber, which is purged with helium. The combustion is initiated by switching the gasflow to oxygen and the transport into the 1000 °C, upright combustion furnace (LF). Ash from the samples is collected in a special ash insert (AI), which can be easily removed and exchanged – even when the unit has reached opera- ting temperature. From all the resulting combustion products (CO2, H2O and N-Oxides), the nitrogen oxides are reduced with the help of copper to elemental nitrogen (N2). Water is separated using an intelligent membrane system (F1, Nafion®), as well as a simple condensation trap. Any remaining water is caught in an absorption trap (F2). The separation of CO2 is done in self-regenerating adsorption traps (F3). Elemental nitrogen remains, which is measured in a thermal conductivity detector (TCD) without any reference gasflow. Data management (input/output) is done via PC