Gravimetric Analysis: Assay Methods

 ASSAY METHODS

A good number of pharmaceutical substances can be assayed gravimetrically. The gravimetric meth-ods adopted vary according to the nature of the substance under determination. However, most of the sub-stances being estimated gravimetrically fall into one or the other categories stated below, which would be discussed briefly with suitable examples :

 

(a) Substances assayed gravimetrically,

 

(b) Substances assayed after conversion :

 

(i) Substances assayed after conversion to Free Acid,

 

(ii) Substances assayed after conversion to Free Base,

 

(iii) Substances assayed after conversion to Free Compound, and

 

(iv) Substances assayed after conversion to Derivatives or Substitution Products.