Acetonitrile as eluent in silver resin column chromatography

Acetonitrile (ACN) is shown to be an effective eluent in combination with methanol (MeOH) or acetone for the rapid separation of polyunsaturated fatty acid methyl esters on a fully silver‐loaded ion‐exchange (XN1010) column. ACN‐containing eluents thus provide on one fully siliver‐loaded resin column an attractive alternative separation system to a series of partially silvered resin columns (“PARC” columns), which previously have been used for such separations. Solvent programming from 0 to 15% ACN in MeOH allows the separation of methyl oleate, linoleate, linolenate and arachidonate within 3 hr. Preparative (up to 800 mg) isocratic separations of a number of polyunsaturated fatty acid esters from natural sources (methyl linoleate from safflower esters, for example) were readily achieved.