EXTRACTION AND CONCENTRATION OF VOLATILES FROM DILUTE AQUEOUS AND AQUEOUS-ALCOHOLIC SOLUTIONUSING TRICHLOROFLUOROMETHANE

A method for extraction and concentration of volatiles from dilute aqueous and aqueous-alcoholic solution using trichlorofluoromethane (Freon 11) is described. Results are given for the recoveries of 1-alkanols, 2-alkanones, and ethyl alkanoates between 2 and 12 carbon number from water and 10% ethanol in a 17-hour extraction. Between 70 and 100% of volatiles of between 5 and 12 carbon number are recovered. The main advantage of the solvent is the high efficiency of extraction of alcohols of C5 and above and the low efficiency for C4 alcohols and below, which makes it particularly well suited to alcoholic beverages and other materials in which ethanol is a major volatile constituent. By treatment of the Freon 11 extracts with propylene glycol, 80 to 90% of the higher alcohol but relatively little of the ester and carbonyl is removed, allowing these compounds to be concentrated further. Other advantages of the method are discussed. © 1969, American Chemical Society. All rights reserved.