Page 474 - Applied Pharmacognosy

• Total ash consists mainly of carbonates,
oxides, silicates and phosphates of Na,
K, Mg and Ca as well as silica.

• At a temperature > 450ºc Carbonates
may be partially decomposed to
volatile oxides. So, some variation in
the amount of total ash occurs.

• Therefore, sulphated ash is
recommended for certain drugs by
the B.P.