Anion selective exhaustive injection-sweep–micellar electrokinetic chromatography

A selective on-line sample concentration technique of anion selective exhaustive injection (ASEI)-sweep–micellar electrokinetic chromatography (MEKC) was evaluated using a cationic surfactant. To suppress the electroosmotic flow, a polyacrylamide-coated capillary was introduced. Some aromatic carboxylic acids, dansyl amino acids, and naphthalenedisulfonic acids were used as test analytes. About 1000- to 6000-fold increases in detection sensitivity were obtained in terms of peak heights by ASEI-sweep–MEKC.