IMPURITIES IN DRUGS. 



(Metals, es- 

 from theJ pecially lead 

 apparatus] iron > and 

 used. L c PP er ' 



Precipitates with (NH 4 ) 2 S, or 

 H 2 S; and special U 



Volumetric test 



Non-volatility ; insolubility 



in HNO 3 . 

 Various tests. 

 Blue colour with iodine. 

 Evaporation ; quantitative 



test. 



In the case of organic drugs, impurities are chiefly 

 to be detected by careful physical examination and 

 special quantitative tests. 



Composition. The composition of the inorganic 

 drugs is expressed by their name and formula. On 



