Residue on Ignition (Sulfated Ash)
A pharmacopoeial test in which a sample is moistened with sulfuric acid and burned at high temperature, usually around 600 °C, until only inorganic residue remains. The weight of that residue, expressed as a percentage, indicates the level of inorganic impurities in an organic substance. It is also called sulfated ash, because metals are converted to their sulfates.
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Loss on Drying (LOD)
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