Carl H. Snyder The University of Miami Coral Gables, Florida 33124
I
I
A Simple "Heavier-than-Water" Extractor
Desirability of simplicity in construction led to the design of the "heavier-than-water" extractor shown in the figure. The extractor consists of three parts: 1 , the extractor body; 2, an inner tube open a t both ends and flared a t three points on its bottom to permit facile liquid flow; and 3, a helix of suitable, inert wire, inserted into the inner tube to divide and disperse solvent drops as they pass through the solution being extracted. I n operation the three parts are assembled as indicated in the diagram and a one neck, round bottom flask is attached to the inner joint, A . Solvent is added at the top opening, B, until the closed tubular portion, C, is filled and overflow to the flask is observed. The solution to be extracted is introduced, with the aid of a long stem funnel, directly into theinner tube. Capacity is reached when the phase interface is pushed to about one cm from the bottom of tube 2. Volume of extracting solvent in the flask can be adjusted by adding solvent in small portions a t B or by removing the flask and adding or removing solvent directly. A condenser with a drop-returning lip is attached to
' Cwnrc, L. C., AND CRAIG,D., "Techniques of Organic Chemistry," (Editor: W ~ I S S ~ B R G Y A I, )R3rd , ed., Interscience Publishers (a division of John Wiley & Sons, Inc.), New Yark, 1956, vol. 111., o a t , I., D. 220. --HARMAN, R. E., J. CHKM. EDUC., 30, 261 (1953). a WEINER, N., "Organic Synthesis," (Edilw: BLATT, A. H.), John Wiley & Sons, Inc., New York, 1943, Coll. "01. 11, p. 378.
.
26
/
.
J o ~ o ol f Chemicol Education
the top joint and the flask is heated. I n a final adjustment after reflux has begun, the condenser is rotated and/or the apparatus is tilted slightly so that returning solvent drips directly into the inner tube. While dimensions are not critical, tube 2 should be as wide as possible, yet still be inserted and removed easily from 1. The capacity of the extractor is determined by the relative densities of the solution and the extraction solvent, and by the length of the closed tube, C, and the diameter of the inner tube. With chloroform as the extracting solvent, about 25 ml of aqueous phase can be extracted in a model in which section C is 15 cm long and the inner tube is 1.3 cm i d . The significant advantage of this extractor over other "heavier-than-water" extractorslJ is its simplicity of construction. Indeed, it is no more than a simple Friedrichsa or KutscherStendel' extractor modified to place the solution being extracted inside the inner tube rather than outside. The author wishes to exc press appreciation to Dr. Howard B. Powell of this Department for valuable comments and assistance in construction of several Diagram of tho extractor. models of this extractor.
