Compositional analysis of small peptides using capillary electrophoresis and Ru(bpy)33+-based chemiluminescence detection

Advances and analytical applications in chemiluminescence coupled to capillary electrophoresis

“…Most of the first contributions appeared before 2000 suffered from poor separation efficiency, low sensitivity and complicated instrumentation. In those studies, RuðbpyÞ 21 3 was added either to the CE running buffer and converted to RuðbpyÞ 31 3 at the exit end of the capillary by use of a separate working electrode [28] or in a small reservoir at the interface between the separation capillary and the working electrode, which was then used to oxidize RuðbpyÞ 21 3 to RuðbpyÞ 31 3 [29][30][31]. Additionally, RuðbpyÞ 31 3 was generated in situ at the interface.…”

“…However, most of the previous studies did not explore the performance of CE-ECL for application to clinical analyses. In those previous designs, an electric field decoupler was used to eliminate the influence of high voltage (HV) field on the ECL detector [31]. However, its use brings peak broadening and involves experimental skill for its manufacturing, while the capillary is easily blocked and also makes the alignment of capillary to electrode more difficult.…”

“…Phosphate buffer (pH 10.8) 31, decoupler [41]. The hydrodynamic cyclic voltammogram and corresponding ECL of RuðbpyÞ 21 3 under the HV field showed that the electrophoretic current did not annihilate the ECL of RuðbpyÞ 21 3 , but made the ECL potential shift more positively and demonstrated that the capillary to electrode distance is crucial to achieve high sensitivity.…”

“…The ECL detector of RuðbpyÞ 21 3 immobilized in ZrO 2 -Nafion composite films containing 53% zirconia showed the maximum ECL intensity and it was checked for the analysis of tripropylamine, lidocaine and proline [62]. The excellent stability of the solid-state ECL detector in the phosphate solution (period of 5-90 h when the solid-state ECL detector was immersed in the solution all the time) extended the application in conventional Electrophoresis 2010, 31, CE. In addition, this detector has been successfully incorporate in the fabrication of a CE microchip [63].…”

“…Some other operations on the cell, such as changing the electrode or capillary, are also greatly simplified. Recently and using the same detection cell assembly, another dual detection mode with ECL and electrochemical (EC) detection has been coupled with non-aqueous CE (NACE-ECL/ EC) for fast analysis of triethylamine, tripropylamine, Electrophoresis 2010, 31, chlorpromazine, promethazine and dioxopromethazine [72]. NACE-ECL/EC could provide more information of analytes, wider linear range, and lower detection limit, and it was successfully utilized for practical application in biological fluids.…”