AXIAL-BEAM ABSORPTION DETECTION FOR CAPILLARY ELECTROPHORESIS WITH A CONVENTIONAL LIGHT-SOURCE

A commercial absorption detector was modified to provide axial-beam absorption detection for capillary electrophoresis. The increased path-length led to improved detection limits. By the use of a nonaqueous solvent, the column is made into an optical waveguide for highly efficient light transmission. The electropherogram integrates the absorbance produced by all components in the sample, but provides information identical to that from normal electropherograms. The mechanical modifications make it possible to switch readily between the cross-beam and the axial-beam geometries.