THE IDENTIFICATION OF ETHYLENE AS A VOLATILE PRODUCT OF RIPENING AVOCADOS

Abstract

An efficient and convenient method was devised for absorbing and identifying ethylene from low concns. in gas streams. Using this technique, ethylene was identified as a volatile product of ripening avocado fruits, as follows: A constant stream of oxygen was passed through large jars containing Fuerte avocados and thence through an absorption apparatus containing bromine in a solvent (methylene chloride). After 6 days, the soln. from the absorber was fractionated under reduced pressure, leaving 650 mg. of clear yellow oil, presumably ethylene bromide. This was reacted with aniline to produce the crystalline derivative, N,N''-diphenylethylene-diamine, and this in turn was reacted with phenylisothiocyanate to produce the derivative, N,N''-diphenyl-N,N''-dianilinothio-formyl ethylenediamine. The identities of these products were established by their melting points and by the melting points of mixtures with authentic samples, demonstrating the original presence of ethylene, A similar result was obtained in an expt. with the Nabal var.