The column selectivity has the highest influence on resolution in chromatography. Therefore, the selection of the best suitable column chemistry for the target analytes is an important selection parameter. C18 column chemistries are typically the first choice. Nevertheless, when a C18 doesn't give the desired separation or the sample contains compounds that are known to be difficult to retain or resolve on a C18, consider changing stationary phases. The range of selectivity provided by Ascentis® Express makes this easy. The flowchart below helps guide users in the selection of an Ascentis® Express phase, based on the particular compound type or separation challenge
The separation goals, detection method and the instrument used for the separation define the column dimension and the particle size.