Direct determination of aliphatic acids in honey by coelectroosmotic capillary zone electrophoresis

Coelectroosmotic capillary zone electrophoresis has been employed for the rapid analysis of 8 aliphatic acids usually present in honey. Polycationic surfactants (hexadimethrine bromide (HDB), cetyltrimethylamonium bromide (CTAB) and tetradecyltrimethyllammonium bromide (TTAB)) have been added to the electrolyte buffer dynamically coating the inner surface of the capillary and causing a fast anodic electroosmotic flow, known as coelectroosmotic flow. The composition of the running buffer (50 mM sodium phosphate adjusted to pH 8 with 1.0 M sodium hydroxide, 25% 2-propanol and 0.001% HDB) and the instrumental parameters (voltage of -20 kV with a hydrodynamic injection for 15 s and an UV detection at 210 nm) have been optimized. Finally, the applicability of the method has been demonstrated for the determination of the aliphatic acids in several kinds of honey without any sample pretreatment.