Abstract: An apparatus and method for interfacing a capillary with a detector is disclosed. In particular, a capillary that is used in a capillary electrophoresis technique is interfaced with an off-column detector that is destructive of the sample or that will otherwise create adverse affects on the operations of the capillary electrophoresis. By way of example only, a nitrogen chemiluminescent detector using pyro-chemiluminescent techniques is discussed. An interface between the separation and detection systems is essential to prevent interference between the two systems. The interface apparatus and method are achieved by creating a closed connection between the two systems within which the pressure and sample flow rate can be controlled. Pressure control is achieved through the introduction and venting of gas into and from the integrated system. Interference between interfaced systems is then prevented by equalizing the pressure in the interface apparatus with the head pressure on the inlet end of the capillary.

Abstract: The present invention provides a method for direct detection concurrently with separation in capillary electrophoresis using a lanthanide cation selected from the group consisting of Tb(III), Eu(III), Dy(III), and Sm(III) to provide fluorescence for enhanced sensitivity. Analytes separated and concurrently detected using this method have an absorption spectrum from about 230 nm to 400 nm and include compounds having an .alpha.,.beta. unsaturated carbonyl group, an .alpha.-keto acid, an aromatic moiety, indole carboxylic acid, a diketone moiety, or an organic acid, for example, a salicylic acid, a carboxylic acid, or an amino acid. Advantages of this method include the lack of derivatization, either pre- or post-column, loss of analyte during derivatization is avoided, and fewer items are needed for a commercial capillary electrophoresis kit.