This thesis aims to separate divinyl ether- and regular fatty acids in capillary electrophoresis (CE) with silver (I) ions as selector. Some attempts of using aqueous buffers were made with unsatisfying results. Consequently the study was mainly performed with nonaqueous buffers. The nature of the solvent in which the sample was dissolved was found to be of great importance. The most promising condition turned out to be running buffers containing only acetonitrile and silver nitrate. However, during the study no separation of the divinyl ether fatty acids was observed. Cis/trans isomers of mono unsaturated methyl esters of fatty acids were also injected in order to investigate if the charge on the divinyl ethers effected the separation negatively. No separation of the fatty acids could be observed either. During the CE runs with the fatty acids an unexpected signal was detected which was shown by UV spectrophotometrical studies to be a result of a complex between acetonitrile and silver (I) ions. The studies showed further that due to this complex the silver (I) ions were not accessible for the analytes, which may explain why no separation could be obtained.