In this article we will discuss about the Kjeldahl method for the estimation of nitrogen in plants. Principle: Digestion of nitrogenous compounds by concentrated sulphuric acid in presence of catalysts (reduced iron powder, and a mixture of CuSO4 and K2SO4) produces ammonium compound. Further, such ammonium compound when distilled by steam in presence of strong alkali (40% NaOH soln.) produces [...]
In this article we will discuss about the complexometric method for estimation of calcium and magnesium in plants. Principle: Many complex-forming ions or molecules lead to a stepwise formation of complexes. Each complex is characterized by its own stability constant. This property of stepwise formation of complex can be used in titrimetry and, thus, one can be able to estimate [...]
In this article we will discuss about the colorimetric method for estimation of amino acids in plants. Principle: Amino acid content can be estimated quantitatively by Colorimetric method using ninhydrin reagent. The reaction of ninhydrin (triketohydrindene hydrate) with amino acids is of particular importance in the regard. Ninhydrin is a powerful oxidizing agent and elicits the oxidative deamination of the [...]