On-chip intermediate LED-IF-based detection for the control of electromigration in multichannel networks.

Monitoring analytes during the transfer step from the first to the second dimension in multidimensional electrophoretic separations is crucial to determine and control the optimal time point for sample transfer and thus to avoid band broadening or unwanted splitting of the sample band with consequent sample loss. A spatially resolved intermediate on-chip LED-induced fluorescence detection system was successfully implemented for a hybrid capillary-chip glass interface. The setup includes a high-power 455-nm LED prototype as an excitation light source and a linear light fiber array consisting of 23 light fibers with a diameter of 100 μm for spatially resolved fluorescence detection in combination with a push-broom imager for hyperspectral detection.