Development of a compact chemiluminescence system coupled with capillary electrophoresis for carbohydrate analysis

As a kinetic process, chemiluminescence (CL) met great challenges while it was used in the detection methods coupled with capillary electrophoresis (CE). In this investigation, a newly recorded ultra-fast CL reaction of luminol-KIO₄-K₃Fe(CN)₆ was observed to be completed in 0.65 s. It was adopted in a simple CE-CL system efficiently to avoid the peak-tailing and overlapping. With this compact system, an indirect determination of rhamnose, d-fructose, sucrose and β-cyclodextrin was realized based on the corresponding negative CL peaks. These peaks were due to the displacement of luminol anions by the analyzed saccharide molecules in alkaline separation electrolyte. In this way, these four saccharides could be separated and determined in 16 min with adequate sensitivities and stabilities. No derivatization or pretreatment was required for the analysis, and it presents an attractive opportunity for routine tests of mono-, di- and oligo-saccharides in a compact CE-CL system, even as a microchip device.