ONLINE MICELLAR ELECTROKINETIC CHROMATOGR APHY MS WITH ELECTROSPRAY-IONIZATION AND ATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION INTERFACES

Two methods were studied for on-line coupling between micellar electro kinetic chromatography (MEKC) and mass spectrometry (MS). A high-molec ular-mass surfactant, diisobutylene-maleic acid copolymer sodium salt (DMA), was used as a new pseudo-stationary phase with an electrospray ionization interface. A DMA micelle functioned successfully as a pseud o-stationary phase, and showed significantly different selectivity for naphthalene derivatives in compared with butyl acrylate/butylmethacry late/methacrylic acid copolymer sodium salt. Five standard compounds ( phenyltrimethylammonium chloride, 1-naphthylamine, quinine sulfate, te traphenylphosphonium chloride and octaoxyethylene dodecanol) were sepa rated by MEKC and detected by MS with DMA. An atmospheric pressure che mical ionization interface (APCI) was used for a conventional MEKC sys tem using sodium dodecyl sulphate and sodium cholate.