The Separation of Salicylic Acid from 5-aminosalicylic Acid Through Bulk Liquid Membranes

In the present paper an experimental study regarding the selectivity upon the separation process of salicylic acid from 5-aminosalicylic acid using the technique of bulk liquid membranes is presented. The optimal separation parameters were established based upon the experimental results obtained at the study of the feed phase pH influence upon the efficiency of the two compounds transport. These results can be closely correlated with the distribution diagram of chemical species in solution depending on the pH. When using a feed phase at pH similar to 2 and a receiving phase at pH similar to 12 the separation of salicylic acid through a chloroform membrane with efficiency higher than 80%, at a transport time of 3 h, was realized. The recovery degree from a mixture of salicylic acid and 5-aminosalicylic acid is over 90 %.