Theme V: Drug analysis methods
The ash determination method allows to identify quickly and easily the physiological and non-physiological materials contained in the vegetable.
The physiological ash comes from the mineral components of the plant itself. But the plant may contain foreign matter adhered to it by contact with the soil and sand.
This foreign matter is called non-physiological ash. Ash content greater than allowed is indicative of an inadequate procedure of collecting and storing in most of the cases.
The British Pharmacopoeia establishes the following method:
Ash determination in herbs drugs:
Incinerate 2-3 grams of the drug in a platinum crucible or silica crucible at a temperature not exceeding 450 º until it carbonizes, cool and weigh.
If carbonized ash can not be obtained by this method, mix the dough with hot water, collect the residue on a filter paper for ash residues, incinerate the residue and the filter paper, add the filtrate, evaporate it to dryness and heat it up at a temperature not exceeding 450 °. Calculate the percentage of ashes referred to air-dried drug.