This analytical method quantitatively determines the total amount of nitrogen and carbon in all forms in soil either using an instrument that utilizes a combustion system with an induction furnace coupled with a thermal conductivity detector (TCD) system and an IR detector system, or, for samples with limited material, an instrument that has a dynamic flash combustion system coupled with a gas chromatographic (GC) separation system and thermal conductivity detection (TCD) system. The analytical 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). The method has a detection limit of approximately 0.02% for carbon and nitrogen.
Sample material must be ground to a powder fine enough to pass through a 60 mesh screen (<0.25 mm).
Sample amount requested: 5 g
Questions concerning limited sample size can be answered by the UC Davis Analytical Laboratory.
AOAC Official Method 972.43, Microchemical Determination of Carbon, Hydrogen, and Nitrogen, Automated Method, in Official Methods of Analysis of AOAC International, 16th Edition (1997), Chapter 12, pp. 5-6, AOAC International, Arlington, VA.