Advancing Capillary-Based Analytical Systems Through Modular Coupling

• Applicant: Professor Dr. Frank-Michael Matysik
• Subject Area: Analytical Chemistry
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441791263

Capillary-based electromigrative separation techniques such as capillary electrophoresis (CE) enable highly efficient separations of complex mixtures of substances, with a focus on preferably charged analytes in this separation method. Due to the small amounts of substances injected into the capillary separation systems, the development of powerful detection concepts and capillary coupling methods is of great importance for fully exploiting the instrumental capabilities. In the coupling of capillary flow systems, the avoidance of dead volumes is an essential criterion for achieving attractive analytical performance. In the previous project, it was possible to achieve dead volume-free splitting of a CE system by coupling amperometric detection (AD) and mass spectrometry (MS). Building on these experiences, various flexible capillary coupling systems are to be developed in the continuation project. One sub-project focuses on connecting two separate amperometric detectors, which are to be implemented in a user-friendly configuration to realize reductive and oxidative AD in synchronized operation (CE-AD2). The second sub-project aims to modify the capillary coupling concepts for the development of AD cells for constructing a CE-Electrospray (ESI)-MS interface that should enable robust MS detection without the addition of a so-called sheath flow solution. It is envisaged to construct the individual components of the interface configuration modularly combinable and interchangeable to also realize a user-friendly development here. The third sub-project plans the development of a new concept for fraction collection in connection with CE separations. Fractionation is intended to take place in a split capillary flow system, with synchronized ESI-MS detection provided alongside fraction collection to characterize the collected CE fractions mass spectrometrically before analytical processing. In contrast to conventional CE fraction collectors, the novel concept does not interrupt the CE separation to further enhance the reliability of targeted fraction collection. Overall, the experiences gained in the first project phase are intended to lead to the development of various modular capillary-based electromigrative coupling systems in the continuation project, which are expected to provide new methodological impulses for the further development of capillary-based separation systems.

• DFG Programme: Research Grants