Separation of Fatty Acids as Theirp-Bromophenacyl Esters on a C30-Bonded Silica Column by High Performance Liquid Chromatography

Abstract

A new C₃₀-bonded silica column was developed for high performance liquid chromatography. This column was tested for the fractionation of fatty acids as their p-bromophenacyl esters by the reverse-phase mode. Certain pairs of fatty acid esters that are very difficult to separate on a C₁₈-bonded silica column, i. e., arachidonic (C₂₀:4)-palmitoleic (C₁₆:1); elaidic (trans C₁₈:1)-vaccinic (cis C₁₈:1); behenic (C₂₂:0)-nervonic (C₂₄:1); and arachidonic (C₂₀:0)-erucic (C₂₂:1) esters, were completely resolved on the C₃₀-bonded column using solvent gradients of acetonitrile: water and acetonitrile: p-dioxane. A solvent system of methylene chloride: acetonitrile (2:1, v/v) was developed for this column to achieve good separation of a homologous series of extremely nonpolar C₇₆ to C₈₂ α-mycolic acid esters from Mycobacterium tuberculosis H37Ra.