MICELLAR ELECTROKINETIC CHROMATOGRAPHY MASS-SPECTROMETRY USING A HIGH-MOLECULAR-MASS SURFACTANT - ONLINE COUPLING WITH AN ELECTROSPRAY-IONIZATION INTERFACE

On-line coupling between micellar electrokinetic chromatography (MEKC) and mass spectrometry (MS) was studied with a high-molecular-mass surfactant and an electrospray ionization interface (ESI). A high-molecular-mass surfactant, butyl acrylate-butyl methacrylate-methacrylic acid copolymer sodium salt (BBMA), was employed as a pseudo-stationary phase for an on-line MEKC-MS system. BBMA and a minor component separated by size-exclusion chromatography were determined by ESI-MS. No major ion from the BBMA polymer was detected. The BBMA micelle functioned successfully as the pseudo-stationary phase in a 10 mM ammonium formate buffer containing 10% methanol. Five standard compounds, phenyltrimethylammonium chloride, 1-naphthylamine, quinine sulfate, tetraphenylphosphonium chloride and octaoxyethylenedodecanol, were separated by MEKC and detected by MS. The effects of the concentrations of BBMA on the separation and sensitivity in MEKC-MS were studied. MEKC-MS with BBMA was applied to the separation and detection of a standard mixture of sulfamides.