This method quantitatively determines the total amount of organic carbon present in soil. Total carbon (TC) is determined using an instrument that utilizes a combustion system with an induction furnace coupled with an IR detector system. This method is based on the oxidation of the sample by “flash combustion” which converts all organic and inorganic substances into combustion gases (N2, NOx, CO2, and H2O). Total inorganic carbon (TIC) is quantitatively determined by measuring the calcium carbonate content using gravimetric analysis and then using a factor of 0.12 to convert calcium carbon to total inorganic carbon (TIC). Soil total organic carbon (TOC) is calculated as the difference between total carbon and total inorganic carbon. The method has a detection limit of approximately 0.02% carbon. Sample material must be ground to a powder fine enough to pass through a 60 mesh screen (<0.25 mm).
Sample amount requested: 30 g
Questions concerning limited sample size can be answered by the UC Davis Analytical Laboratory
Western Region Method S 9.30, Total Nitrogen and Organic Carbon – Combustion Method); Soil, Plant and Water Reference Methods for the Western Region, WREP-125, 4th Edition, 2013.
Western Region Method S 13.10, Soil Carbonate – Gravimetric Determination); Soil, Plant and Water Reference Methods for the Western Region, WREP-125, 4th Edition, 2013.
