Columns and Detectors Recommended in Gas Chromatography to Measure Greenhouse Emission and O2 Uptake in Soil: A Review

Abstract

ABSTRACTGas chromatography (GC) is a technique used to analyze substances/molecules (as chemical species) with a system composed of chromatograph, column, and detector. This study has the objective of reviewing the use of GC in monitoring greenhouse gases (GHG; carbon dioxide: CO2; methane: CH4; nitrous oxide: N2O) emission and O2 (oxygen) uptake in soil, demonstrating results from experiments around the world and alternative use of sensors to monitor these gases in soil. Our study shows that the correct column and detector depend on analyzing gas and the advantages and disadvantages of the column and the detector. The columns, packed and capillary, have been more used and are considered better options to analyze GHG emission and O2 uptake in soil science. Thermal conductivity detector (TCD), electron capture detector (ECD) and mass selective (MS) are great choice to monitor CO2 emission; flame ionization detector (FID) equipped with methanizer allows the detection of CO2 and CH4 emission; and ECD detects the amount of N2O emitted. Moreover, both, TCD and ECD, also can be used to detect O2 uptake. GC system is complex, and to identify of GHG emission and O2 uptake is necessary the use of column (packed or capillary) and may contain multiple detectors, i.e. three (TCD, ECD, and FID) or two detectors (FID and ECD). Field and laboratory study should be run to verify the efficacy of sensors to monitor GHG emission and O2 uptake as an alternative of GC system.