Provided is a method for control and/or monitoring and/or optimization of a chromatographic process, in which the method comprises at least 2 columns which are operated, alternatingly, wherein this operation can be carried out in that the at least 2 columns are operated in interconnected and disconnected states, wherein the columns switch positions after such a sequence of interconnected and disconnected state,
and wherein downstream of at least one, or of each column, a detector is located capable of detecting the desired product and/or impurities when passing the detector.