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Evaluation of the twitchell isooleic method: Comparison with the infrared trans‐isooleic method
Author(s) -
Jackson Frank L.,
Callen Joseph E.
Publication year - 1951
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02612093
Subject(s) - infrared , cis–trans isomerism , infrared spectroscopy , simple (philosophy) , chemistry , solubility , computational chemistry , materials science , analytical chemistry (journal) , mathematics , chromatography , stereochemistry , organic chemistry , physics , optics , philosophy , epistemology
Conclusion The Twitchell and infrared isooleic methods have been compared. Assuming that all trans‐isooleic acids are of equal significance as regards influence on shortening plasticity as “solid unsaturated acids,” the infrared method is superior. This method has all the advantages of speed and accuracy of spectrophotometric methods. It handles simple and complex isoleate mixtures with equal ease in view of identical infrared absorption for trans‐isomers of different double bond position. The Twitchell method was shown, on close analysis, to have fair accuracy for simple trans‐acid mixtures but give very low values (errors of 35 to 45%) with ordinary hydrogenated oils. The reason for the failure of the Twitchell method apparently lies in the increasing lead isooleate solubility with increase in the number of trans‐isooleic acids.