Capillary Electrophoresis Chemiluminescence Detection Research Articles

Compact detection cell using optical fiber for sensitization and simplification of capillary electrophoresis–chemiluminescence detection

A new and simple chemiluminescence detection cell using optical fibers was designed for capillary electrophoresis. The cell was easily combined with capillary electrophoresis equipment and the system was operated without any tedious procedures. Luminol chemiluminescence was adapted for use with this detection cell. Hydrogen peroxide and catalysts were examined in detail with respect to their usage and concentration using the cell. The detection limit for luminol was 5.0·10 −10 M (14 amol; S/ N=3), which was the most sensitive result reported so far. Also, a mixture of glycine, glycylglycine and glycylglycylglycine, which was labeled with isoluminol isothiocyanate, was subjected to the present system. They were sensitively detected and were baseline separated.

Determination of codeine, 6-methoxycodeine and thebaine using capillary electrophoresis with tris(2,2′-bipyridyl)ruthenium(II) chemiluminescence detection

A simple and robust capillary electrophoresis chemiluminescence detection system for the determination of codeine, 6-methoxycodeine and thebaine is described, based upon the reaction of these analytes with chemically generated tris(2,2′-bipyridyl)ruthenium(III) prepared in sulfuric acid (0.05 M). The reagent solution was contained in a glass detection cell which also held both the capillary and the cathode. The resultant chemiluminescence was monitored directly using a photomultiplier tube mounted flush against the base of the detection cell. The methodology, which incorporated a field amplification sample introduction procedure, realised detection limits (3σ baseline noise) of 5 × 10–8M for both codeine and 6-methoxycodeine and 1 × 10–7M for thebaine. The relative standard deviations of the migration times and the peak areas for the three analytes ranged from 2.2 up to 2.5% and 1.9 up to 4.6%, respectively.