Question

Describe plant ash analysis.

Answer 1

• This method is used to determine the presence of a relative amount of various elements in the plant.
• In this method when fresh plants are dried at $70-{80}^0$C in the oven for one or two days so that, all water present in the plant is driven off.
• The remaining part is weighed and the dry weight of the plant is obtained.
• The main constituents of the dry matter are the polysaccharides, lignin, proteins, fats, organic acids and some other elements.
• This dry matter is burnt in a furnace at ${600}^0$C, as a result, all organic compounds are oxidized and are driven off in the form of gases ($C{O}_2$, $N{H}_3$ and $S{O}_2$ etc.)
• The remaining material is called plant ash and contains only mineral elements.
• The relative amount of various minerals can be determined by analysis of this ash. However, the extent of their utilization and essentiality cannot be determined by this method.