Nonaqueous capillary zone electrophoresis for separation of free fatty acids with indirect fluorescence detection.

The feasibility of combining nonaqueous capillary zone electrophoresis with indirect fluorescence detection was studied for the efficient separation and sensitive detection of ionizable hydrophobic substances which do not possess practically suitable detection properties. Medium- and long-chain free fatty acids, C6-C24, were selected as test compounds. The results showed that such a wide range of medium- and long-chain free fatty acids could be separated between any two consecutive homologs in one run and be detected at a level of about 0.01-0.02 mM in highly basic methanol/acetonitrile media containing fluorescein as coion of background electrolyte for indirect fluorescence detection.