Pharmaceutical Analysis

Chapter 1

Analysis of Hydroxyl Groups

The hydroxyl groups are analysed by the following analytical methods:

• Reaction methods: These methods are mainly based on the measurement and interpretation of the substances absorption when the samples are reacted with the absorption reagents or with the normal reactants. The detection is carried out by using any spectrometric method:
  1. Esterification method: This method is widely applicable analytical method for the analysis of hydroxyl groups based on their reaction to form esters.

      

     R–OH + RCOOH RCOOR + H₂O

      

     However, this reaction is slow to enhance the rate of reaction. The acid chlorides are used, and sometimes, acid anhydrides are used as acetylating agents.

      

     R–OH + R¹COCl R¹COOR + HCl

      

     R–OH + (R ...