Stacking of neutral analytes in micellar electrokinetic chromatography

On-line concentration techniques for neutral analytes by sample stacking in micellar electrokinetic chromatography are reviewed. Discussions regarding the fundamentals and practical applications are conveyed. A high gain in sensitivity of 10- to more than 100-fold using normal capillary cell dimension is provided without crucial loss of resolution by the techniques. More than 1000-fold gain in sensitivity (lowering limits of detection to the nM range) is obtained together with an extended pathlength cell.