The liquid—liquid extraction of tricyclic amines (antidepressants) was optimised using mixture experimental designs, the physical part of which was performed by a laboratory robotic system. This system was controlled and directed by a second, external computer. After extraction, phase separation, evaporation of the organic phase and reconstitution of the residue, the final step was the on-line injection of the extracts in the reversed phase high-performance liquid chromatographic (RP-HPLC) system. Criteria used in this optimisation procedure were the extraction yield (recovery) and the partition coefficient. For simultaneous extraction of several compounds the minimal recovery was used as criterion. A totally automated extraction optimisation procedure was now obtained. It was concluded that the robot is suitable for the performance of automated optimisation.
