Time-resolved luminescence detection of europium(III) chelates in capillary electrophoresis

Abstract

An instrumentally simple on-column time-resolved luminescence capillary electrophoresis (CE) detector for determining and characterizing migrated europium(III) chelates on the basis of their long-lived ⁵D₀→⁷F-multiplet transitions has been constructed. In addition to the background fluorescence arising from the cell walls, this time-resolved luminescence method of measurement also allows an efficient discrimination of the analyte emission against the short-lived background fluorescence caused by possible fluorescent impurities in the electrophoresis buffer; this should provide a feasible means of constructing a CE detector for the trace analysis of europium(III) chelates and also of samples of biological interest labelled with europium(III) chelates. If supplied additionally with a device for determining the excited-state lifetimes of separated europium(III) chelates, this time-resolved luminescence detector should make possible the peak identification of migrated europium(III) chelates.