Page 144 - Applied Pharmacognosy
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Mobile Phase Selection

             Problems Encountered with Alkaline Eluents

❑ Second Problem: Influence of Residual Silanol Groups.

                                                                 Basic substances interact with the

How to solve these two problems?? residual silanol groups, causing

                                                                       delayed elution and tailing.

   Si
O

Si -O-Si-O

   Residual silanol group  N  +
                           H
O

Si

Using an acidic buffer suppresses dissociation of residual
silanol groups and reduces their influence to some exte1n43t.
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