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Gas liquid chromatography of the hydroxy‐, acetoxy‐and oxo‐stearic acid methyl esters
Author(s) -
Tulloch A. P.
Publication year - 1964
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/bf02663968
Subject(s) - chemistry , substituent , stearic acid , ethylene glycol , carbon chain , structural isomer , carbon fibers , carbon number , organic chemistry , cis–trans isomerism , alkyl , silicone , fatty acid , ethylene , chromatography , catalysis , materials science , composite number , composite material
Carbon numbers have been determined for all the 17 isomeric methyl hydroxy‐ and acetoxystearates and for 15 of the 16 isomeric methyl oxostearates using silicone SE‐30, silicone QF‐1, and ethylene glycol succinate (EGS) as liquid phases. The carbon numbers of the isomers increase with increasing distance of the point of substitution from the carboxyl end of the fatty acid chain (the increases for the 4‐ and 5‐hydroxy esters are unexpectedly large). The change in carbon number from one isomer to the next is greatest when the substituents are attached near either end of the chain. The best separation of isomers with the substituent near the carboxyl end is obtained for oxo esters using the QF‐1 column, and that of isomers substituted near the methyl end is obtained for acetoxy esters using the EGS column. Isomers with substituents at carbons 9<13 are not distinguishable on any of the columns used, but the other isomers are partly or completely separated. The quantitative aspects of the separations have not been investigated.