Fundamentals of micellar electrokinetic chromatography (MEKC)

Steady‐State Continuous‐Flow Purification by Electrophoresis

“…A mixture of three dyes (rhodamine B, rhodamine 6G, and fluorescein) was continuously injected by a syringe pump that provided uninterrupted injection for 12 h. The stability of separation was judged by the steadiness of the three streamlines. [26][27][28] Dielectrophoresis, another example, uses non-uniform electric fields to separate uncharged species with different dipole moments. On the other hand, only negligible widening of streamlines during their passage through the separation channel suggests minimal contribution from multiple sources of band-broadening such as diffusion, injection bandwidth, convection, and hydrodynamic broadening.…”

“…Micellar electrokinetic chromatography uses charged surfactants, at concentrations that are greater than critical micelle concentration, to separate uncharged species with different hydrophobicities. [26][27][28] Dielectrophoresis, another example, uses non-uniform electric fields to separate uncharged species with different dipole moments. [29,30] Achieving steady-state continuous separation, with a technologically simple solution, will stimulate efforts aiming at practical integration of continuous microsynthesis with continuous purification.…”

Updated Review on Micellar Electro kinetic Chromatography

“…Therefore, analytes that have greater affinity for the micelles exhibit slower migration velocities compared with analytes that are mostly distributed in the bulk solution with SDS micelles, the general migration order will be exactly the opposite as in ECZ: anions, neutral analytes and cations. Anions will remain mostly in the bulk solution due to electrostatic repulsions from the micelle; neutral molecules will be separated exclusively due to their hydrophobicity; while cations will migrate last due to the strong electrostatic attraction [1,2]. This generalization regarding the migration order can be sometimes useful, but strong hydrophobic interaction between analytes and micelles can overcome repulsions and attractions.…”

Recent methodological and instrumental development in MEKC

“…Micellar electrokinetic capillary chromatography (MEKC) as a type of an electro‐driven separation tool is an efficient analytical technique due to low reagent consumption, high efficacy and selectivity with reasonably short analysis time . Unfortunately, the technique still suffers from low detection sensitivity due to small volume of injected sample and short path length, which faces the detector .…”