Control of dispersion in capillary electrochromatography coupled to UV and mass spectrometric detection

Capillary electrochromatography (CEC), along with other miniaturised chromatography techniques, such as capillary LC, offers the most benefit when efficiently coupled to mass spectrometric (MS) detectors. In conventional one-piece CEC columns, dispersion in the open connecting tube between the packed column and MS source reduces chromatographic performance to unacceptable levels. This paper examines the effect on dispersion of various column-tube arrangements and offers suggestions as to the most practical way of connecting CEC–UV–MS. Comparisons of theoretical and measured values for these different arrangements are shown.