A liquid chromatography to capillary array electrophoresis interface for two-dimensional separations

A new liquid chromatography-capillary electrophoresis interface has been developed for multidimensional separations. The interface allows two second dimension separation capillaries to sample the chromatography effluent by servo controlled positioning of the capillary inlets in either the effluent or background electrolyte streams. The use of multiple second dimension capillaries allows higher first dimension sampling rates or multiple second dimension separation modes. Fluorescently labelled serum was separated by gel filtration and sub-micellar capillary array electrophoresis producing a multidimensional separation. Alternatively, using different background electrolytes for each capillary, two multidimensional separations with different selectivities were collected simultaneously. An easily fabricated PDMS multichannel sheath-flow cuvette was used for sensitive laser induced fluorescence detection of the labelled serum.