Novel pre-fractionation method of trans fatty acids by gas chromatography with silver-ion cartridge column.

We developed a novel pre-separation method of trans fatty acids (TFAs) using a silver-ion cartridge column and GC. As a preliminary study, a mixture of fatty acid methyl esters consisting of saturated, cis-unsaturated, and trans-unsaturated fatty acids was dissolved in dichloromethane and loaded onto a Bond Elut SCX ion-exchange cartridge column that was converted to the silver-ion form. The column was then eluted with dichloromethane to obtain the saturated fatty acids, dichloromethane/ethyl acetate (90/10) for the trans mono-ene, dichloromethane/ethyl acetate (65/35) for the cis mono-ene, dichloromethane/acetone (60/40) for the trans di-ene, and acetone/acetonitrile (80/20) for the others.