Fatty methyl esters can be prepared easily by direct acid transesterif
ication. If conjugated fatty acids are present, soft techniques must b
e used, In spite of new polar phases and capillary columns, the comple
te separation of all the fatty acids cannot be obtained by GC. However
, the resolve some of the isomers, The derivatisation utilisation of s
ilver ion HPLC and TLC helps to of fatty acids in DMOX, picolinyl and
MTA derivates enable the determination of the double position by GC-MS
, GC-FTIR achieved the determination of the geometrical configuration.