A fully automated liquid-liquid extraction system utilizing interface detection

The development of the Abbott Liquid-Liquid Extraction Station was a result of the need for an automated system to perform aqueous extraction on large sets of newly synthesized organic compounds used for drug discovery. The s ystem utilizes a cylindrical laboratory robot to shuttle sample vials betwe en two loading racks, two identical extraction stations, and a centrifuge. Extraction is performed by detecting the phase interface (by difference in refractive index) of the moving column of fluid drawn from the bottom of ea ch vial containing a biphasic mixture. The integration of interface detecti on with fluid extraction maximizes sample throughput. Abbott-developed elec tronics process the detector signals. Sample mixing is performed by high-sp eed solvent injection. Centrifuging of the samples reduces interface emulsi ons. Operating software permits the user to program wash protocols with any one of six solvents per wash cycle with as many cycle repeats as necessary . Station capacity is eighty, 15 ml vials. This system has proven successfu l with a broad spectrum of both ethyl acetate and methylene chloride based chemistries. The development and characterization of this automated extract ion system will be presented.