Flow-Type Chemiluminescence Detection Cell Using an Optical Fiber for Capillary Electrophoresis

Publisher Website
Google Scholar
Abstract
A flow-type chemiluminescence detection cell using optical fiber was designed for capillary electrophoresis. The capillary was set up straight to the optical fiber with a certain distance in a Teflon® tube. Hydrogen peroxide was delivered through a three-way joint by a syringe pump and mixed with analytes at the capillary outlet. Luminol chemiluminescence was adapted for use with this detection cell. Analytical conditions, such as hydrogen peroxide flow rate, distance between the capillary and the fiber, and the reagent concentrations, were examined in detail with the cell. The present flow-type system provided a CL signal with high sensitivity, resolution, and reproducibility. The detection limit (S/N = 3) for luminol was 7.6 × 10−9 M (28 amol; 3.7 nl injected) with theoretical plate numbers of 130000—160000 and a relative standard deviation of 3.3% for the peak height (n = 10). A mixture sample of glycine, glycylglycine, and glycylglycylglycine, which were labeled with isoluminol isothiocyanate (2,3-dihydro-6-isothiocyanato-1,4-phthalazinedione), was also subjected to the present system. They were sensitively detected and represented with high resolution.