Determination of Dry Matter and Inorganic Ash

Weigh accurately less than 2g of sample into a weighed silica crucible, place in oven at 105 °C for 24 h, cool in desiccator and weigh. Calculate dry matter fraction. Place crucibles at random in furnace chamber and switch on furnace, if not starting from cold, hold furnace at about 250 °C until no further smoke is given off. 

Increase temperature after 3 h until 550 °C is reached. Cool in the desiccator and weigh. Calculate total ash as a proportion of the sample dry matter. 

---