EA: Elemental analyzer
The EA converts carbon contained in organic (soil, plant material, specific compounds etc.) samples into CO2. The sample material is weighed into tin or silver boats and burned at 950 ° C in a combustion tube in a constant stream of helium with the addition of oxygen. Resulting combustion gases (CO, CO2, NO, NOx, H2O, etc.) are then completely oxidized by copper oxide contained in the combustion tube, e.g. CO to CO2. Pieces of copper wire in the reduction tube reduce excess oxygen to copper oxide and nitrogen oxides are converted to nitrogen. The resulting gas mixture (CO2, H2O, N2) is separated by chromatography, so that pure CO2 is obtained in a helium stream. Depending on the sample size, this is either graphitized in the AGE or, after direct concentration in the GIS, measured as a gas sample with the MICADAS.