Abstract: A high-duty-cycle liquid chromatography system that includes two or more columns that are configured to alternatingly be in a productive phase or a regeneration phase, wherein simultaneously one of the columns is in a productive phase and the other columns are in the regeneration phase. Additionally, the system includes a mobile phase gradient delivery pump, an isocratic pump, two or more gradient storage chambers, and two or more valves that are each independently coupled to a column and a gradient storage chamber. The column in the productive phase has a solution containing a sample which is pushed through the column, collected at a detector, and analyzed. The column in the regeneration phase is being prepared for the next productive phase.