Evaluation of the concentration of compounds in the distillation solution on the quantification of total nitrogen by the Kjeldahl method
Giselle Priscila Costa, Tadeu Eder Silva, João Paulo Pacheco Rodrigues, Edenio Detmann
Journal Title:Revista Agraria Academica / Agrarian Academic Journal
Optimizing the reagents on distillation solution used in the Kjeldahl method could be an important strategy to decrease risk to environmental and human health and consequent reduction in analysis costs. Here, we testedfourdistillation solutioncombiningtwo concentrations of boric acid(40 or 20 g/L) and two alcohol solutions of the indicators(methyl red and bromocresol green, 25 mL/L and 12 mL/L,or 12.5 mL/L and 6 mL/L) in fifteen samplesof low-and high-N materials.We demonstrated that a reduction of concentrations of those reagents does not affect the total N quantification in the different materials.