Glucose Unit Computation in Capillary Zone Electrophoresis of Carbohydrates using a Numerical Approximation Based Search for a Virtual EOF Marker. A Tutorial

Several high-resolution carbohydrate separation methods are currently available for structural elucidation in the analytical glycomics field, but the associated glyco-informatics support is lagging. Identifying protein-bound glycan structures represents a multifaceted challenge with elements of separation science, bioinformatics, and sophisticated computational methods. In electroosmotic flow (EOF) driven separations with counter currently migrating sample components, the apparent migration times of the analyte molecules are the result of the interplay between their effective electrophoretic mobilities and the EOF. The resulting continuously increasing migration time distances between the consecutively migrating maltodextrin oligomers make glucose unit value calculation and the subsequent structural interpretation of unknown glycans extremely challenging. To correct this irregularity, a numerical approximation-based search-derived virtual electroosmotic flow marker is introduced and utilized. This tutorial guides the reader through the computation process for structural elucidation of N-linked carbohydrates by using a detailed worked example with a monoclonal antibody of biopharmaceutical interest.