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 α,β unsaturated carbonyl group, an α-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. |