USE OF THE COLEMAN MODEL 29A ANALYZER FOR TOTAL NITROGEN ANALYSIS OF SOILS

Publisher Website
Google Scholar
Abstract
Studies to evaluate an automated Dumas procedure for determina tion of total soil N showed that maximal total N values were obtained by a procedure involving combustion of soil mixed with wire-form CuO-Pt catalyst at 940[degree] C for 12.6 min. in a tube filled with this catalyst. This procedure permitted analysis of up to 3 g of mineral soil containing up to 0.4 ml of water and gave almost quantitative recovery of nitrate N and nitrite N added to soil. A comparison of the results obtained in total N analysis of soils by this Dumas procedure and by Kjeldahl and HF-Kjeldahl techniques showed that, when applied to surface samples of mineral and organic soils, these methods gave practically identical results whereas their results with 2 subsoils containing large amounts of fixed ammonium were in the order: HF-Kjeldahl > Dumas > Kjeldahl. The findings reported indicate that total N in most soils can be determined satisfactorily by Dumas or Kjeldahl methods but that these methods do not give complete recovery of native fixed ammonium N in some soils containing high levels of fixed N.

This publication has 1 reference indexed in Scilit: