APRIL, 1953
0
A CONTINUOUS LIQUID-LIQUID EXTRACTION APPARATUS J. EARL DANIELEY' University of North Carolina, Chapel Hill, North Carolina
THE literature contains diagrams and descriptions of several different designs of equipment which can be used for continuous liquid-liquid extraction. The Friedrichs extractor is very useful for small amounts of material hut is not readily adaptable to large or variable q ~ a n t i t i e s . ~Others which are described use rubber stoppers which may he very undesirable.^. 4. 6 Some of those described require considerable time for a s ~ e m b l y . ~ -Still ~ another seems to he ideal for working with very large quantities but is more difficult to use with small or varying amounts of material.' Recently THIS JOURNAL published a diagram of an apparatus designed for continuous extraction hut which might prove difficult to fabricate in the average laboratory.8 The apparatus shown in the accompanying diagram, as designed and constructed in this laboratory, is not difficult to fabricate; it is easy to assemble, and can be used with flasks of varying size. All connections are ground-glass joints of standard taper, 24/40. Flasks of I-, 2-, and 3-liter capacity have been used with the apparatus by varying the length of the neck on the flask. The 3-liter flask, E, has a very short neck, whereas the 1-liter flask, F, has a neck which is 11.5 cm. in length. It has not been necessary to use any mechanical stirring; however, stirring might be very conveniently carried out by making the bubbler, G, shorter and then using a magnetic stirrer. Ether is boiled in flask H and the vapors rise to an efficient condenser, A. The liquid ether is distributed throughout the mixture by the bubbler, G. The ether 'Associate Professor of Chemistry, Elon College, North Car* lina. On leave of absence WEINER, NATHAN,"Organic Syntheses," John Wiley & Sons, Inc., New York, 1944, Coll. Val. 11, p. 378. 'ASTON, J. G., el. al., "Organic Syntheses," John Wiley & Sons, Inc., 1943, Val. 23, p. 49. ' CAMPBELL, K.N., AND A. H. SOMMERS, 'rO~ganicSyntheses," John Wiley & Sons, Inc., New York, 1948, Vol. 28, p. 66. 'WILSON,W. C., "Organic Syntheses," 2nd ed., John Wiley 6r Sons, Inc., New York, 1941, Coll. Vol. I, p. 277. 'Cox, G. J., AND HARRIETPEKING, "Organic Syntheses," John Wiley & Sons, Inc., New York, 1944, Coll. Vol. 11, p. 615. 7 PEARL, I. A,, Ind. and ~ n g Chem., . AWL ~ d . 16, , 62 (1942). a HOLLIMAN, F.G., J. CHEM.EDUC.,29,96 (1952). .
Liquid-Liquid Eit.-ctoz
carrying the compound which has been extracted is then returned to the boiling flask. The apparatus has been used continuously for long periods without appreciable 108s of material. Solid glass rods, C, are used to strengthen the apparatus.
