Sample stacking revisited: a personal perspective.

One of the major challenges in capillary electrophoresis and other miniaturization separation techniques is to maintain high detection sensitivity in the increasingly smaller dimension. Numerous on-column sample preconcentrating procedures, based either on electrokinetic focusing or chromatographic effects, have been developed. This review will discuss some practical approaches to sample stacking from a personal perspective. Several recent developments in sample stacking on microfluidic devices are reviewed.