On-chip intermediate fluorescence, conductivity and electric potential detection for 2D electrophoretic separations

SYDES, DANIEL; KLER, PABLO A.; LUTZ, D.; ZIPFL, P.; MEYER, HANS; HUHN, CAROLIN

GRAZ

Congreso; ANAKON 2015; 2015

The analyte transfer from the first to the second separation dimension is one of themost challenging aspects in 2D electrophoretic separations by means of minimizing band broadening, transfer timing and ensuring orthogonally of both separation dimensions. Previously, we introduced a modular hybrid 2D electrophoretic separation approach using a microfluidic chip interface with capillary contactless capacitively coupled conductivity detection (C4D) and mass spectrometry. We here present first proof of principle for on-chip C4D, fluorescence and intermediate electric potential detection for 2D electrophoretic separations.Intermediate C4D detection was implemented for the simultaneous ITP-C4D/CE-MS analysis of the 20 proteinogenic amino acids.Spatially resolved on-chip fluorescence detection was realized via a linear optical fiber array and a push broom scanner for spectrally/spatially resolved detection. On-chip potential measurements for ITP and CE measurements were conducted via a passivated electrode inside the chip interface to monitor and thus control potential variations during electrophoretic separations.