Chromatographic techniques to determine conjugated linoleic acid isomers

Conjugated linoleic acid (CLA) is a complex mixture of positional and geometric isomers that contains a conjugated double-bond system and exhibits health-promoting attributes. Although cis-9 trans-11 is the predominant species in dairy foods and biological subtracts, there is a real need to determine the CLA-isomer distribution, since the isomers may have different biological functions. This review covers the latest advances in the analytical techniques, mainly GC-MS and Ag+-HPLC, to determine the isomeric profile of CLA.