Hybrid capillary-microchip setup for 2D-electrophoresis coupled to mass spectrometry

KLER, PABLO A.; HUHN, CAROLIN

Heidelberg

Conferencia; EMBL comference Microfluidics 2012; 2012

EMBL - Heidelberg

Due to the complexity of biological systems, the need of more accurate and efficient analytical tools is continuously growing. Despite the success of liquid chromatography or capillary electrophoresis (CE) coupled to mass spectrometry (MS), many analytical questions remain unsolved due to the large number of analytes in a wide range of concentration, as is the case in proteomics and metabolomics. In order to face these challenges, we develop novel analytical platforms based on electromigrative separation techniques to combine excellent separation performance, on-line pre-concentration and mass spectrometric detection for the analysis of complex biological samples. We here describe a novel hybrid capillary-microchip module for 2D-electrophoretic separations coupling isotachophoresis with capillary electrophoresis (ITP-CE). This instrumental setup combines the versatility of commercial CE equipment with precision and accuracy of microfluidic chips: we use the first for channel filling, injection and electric potential control, and the second for an optimal sample transfer between columns. The ITP-CE coupling enables us to sequentially perform first ITP for on-line pre-concentration with matrix removal and second a highly efficient CE separation coupled with mass spectrometric detection for analyte identification and quantification. Different modes of ITP-CE regarding the composition of leading, termination buffer and background electrolyte are evaluated. Finally, the new instrumentation and methods are applied to the separation and identification of compounds of biological interest in order to demonstrate the analytical capabilities of the developed system.