Development and Evaluation of a Rotary Cell for Capillary Electrophoresis−Chemiluminescence Detection

Many efforts have been made toward the advancement of capillary electrophoresis chemiluminescence (CE−CL) detection and its applications through continuous development and improvement of interfaces. In this study, a novel rotary cell for CE−CL detection was fabricated and evaluated. A ring-shaped narrow channel with a quartz bottom is made in a cell body to hold CL reactants and act as the reaction chamber. The CE capillary is placed closely to the bottom of the reaction chamber where analyte is deposited into the CL reactants for reactions to occur. Detection is achieved with a photomultiplier tube below the reaction channel. An advantage of the rotary reaction cell is that it renews the reactants at the capillary end as it revolves at a preset speed during experiments. The rotary detection cell presents a new concept to the conventional coaxial-flow configuration by solving the problems of bubble formation and flow blockage that often interrupt the electrophoresis. Two standard proteins, horseradish peroxidase (HRP) and hemoglobin (Hb), were used to evaluate the interface’s performance with luminol/H2O2 CL system. Satisfactory sensitivities (LOD of 0.91 × 10−9 M for HRP, and 4.37 × 10−8 M for Hb at S/N = 3) were obtained in this proof-of-concept experiment. This novel design provides a straightforward and robust interface for CE-CL hyphenation.