Journal of Lipid Research, Vol 28, 338-342, Copyright © 1987 by Lipid Research, Inc.
Analysis of positional isomers of monounsaturated fatty acids by high performance liquid chromatography of 2,4-dinitrophenylhydrazones of reduced ozonides
CR Caughman, LC Boyd, M Keeney and J Sampugna
A method is described for quantifying the positional isomers in
monounsaturated fatty acid methyl ester (FAME) fractions. The procedure
involves the preparation of 2,4-dinitrophenylhydrazones (DNPH) of the
fragments generated during reductive ozonolysis of FAME, class isolation of
the aldehyde and aldehyde ester DNPH, and separation of the aldehyde ester
derivatives by high performance liquid chromatography (HPLC). The high
extinction coefficient of the DNPH provides for a sensitive assay which is
linear for a large range of components over a concentration range of
0.075-5 nmol/component, and the stability of the DNPH permits the
independent analysis of the aldehyde and aldehyde ester fragments generated
during reductive ozonolysis. The reductive ozonolysis-DNPH-HPLC method
developed is as sensitive, reproducible, and accurate as reductive
ozonolysis-gas- liquid chromatography and does not suffer from some of the
drawbacks of the classical procedure.