Tris(2,2 prime -bipyridyl)ruthenium(III) as a Chemiluminescent Reagent for Detection in Capillary Electrophoresis

A post-column chemiluminescent technique for the detection of compounds that are poor chromophores using electrogenerated chemiluminescence following separation by capillary electrophoresis is described. The luminescent signal is generated following the reaction of analytes (e.g. amines) with Ru(bpy)33+, which is electrochemically generated post-column from Ru(bpy)32+. Tripropylamine and proline are used as two model compounds to demonstrate the feasibility of the method. Detection limits for the prototype system were in the micromolar range, suggesting that this technique offers an alternative to indirect detection of compounds that are poor chromophores with an added selectivity advantage. The system includes the use of a conductive joint to isolate the separation field from the potential necessary to drive the electrogenerated chemiluminescent reaction. Addition of the chemiluminescent reagent Ru(bpy)32+ post-column did not decrease the efficiency of the separation. The design and fabrication of the novel cell is discussed.