A direct procedure for the micro-scale preparation of acyl derivatives of nucleophilic drugs from carboxylic acids for gc separation and identification.

Free carboxylic acids were converted into mixed anhydrides suitable for the acylation of nucleophilic drugs in a one-step procedure. By preparing more than one acyl derivative and comparing the retention times of the derivatives with those of authentic drug samples with reference to suitable internal standards, the positive identification of unknown drugs was possible. The method is suitable for use in conjunction with the microphase extraction of drugs.