Die Bodenkultur - Journal for Land Management, Food and Environment


Measurement of actual and potential denitrification and soil respiration with an automated gas chromatographie system


The described instrument was developed out of the demand to get a most versatile and effective gas analyser with limiting amounts of investment money and analysis time. It consists of a gas chromatograph with a Thermal Conductivity Detector and an Electron Capture Detector, three electromagnetic valves, a Porapak and a Molecular Sieve analysis column. An automatic Head Space Sampier can be attached. The described setup can be used for several methods concerning gas metabolism in soils but it is focused on the routine measurement of ambient nitrous oxide concentrations as well as of high nitrous oxide concentrations as obtained in potential denitrification experiments. Carbon dioxide is measured simultaneously with nitrous oxide. Neon can be used as internal standard. Oxygen can be measured simultaneously with carbon dioxide after a slight alteration of the setup. Frontflush of acetylene and backflush of oxygen are installed to promote baseline stability and a long lifetime of the ECD. Key-words: soil microbiology, methods, gas chromatography, denitrification, respiration.