On‐line combination of micellar electrokinetic chromatography and mass spectrometry using an electrospray–chemical ionization interface

Micellar electrokinetic chromatography/mass spectrometry (MEKC/MS) using an electrospray–chemical ionization (ES‐CI) source is described. The interface between micellar electrokinetic chromatography and mass spectrometry consists of an electrospray‐type nebulizer and an atmospheric pressure chemical ionization source that uses a needle electrode. Aromatic amines (aniline, p ‐nitroaniline, and 1‐naphthylamine) are analysed by MEKC/MS, using a phosphate buffer that includes 20 mM sodium dodecyl sulfate (SDS), and protonated molecular ions of the samples are clearly recorded on the ion electropherograms. The results show that the ES‐CI technique is very promising as an MEKC/MS interface since MEKC/MS uses a high concentration of nonvolatile salts and surfactants.