The invention relates to a method for separating a mixture in a system comprising a plurality of chromatography columns, the method successively comprising, in a cyclical manner, in a given part of the system: a step of collecting a raffinate; a step of injecting the mixture to be separated; a step of collecting an extract; and a step of injecting a mobile phase; the method further comprising: determining, in a node of the system, the history of a variable representing the concentration of at least one species contained in the mixture to be separated; detecting, within said history, a characteristic point between the beginning of a step of collecting the extract and the end of the following step of collecting the raffinate; comparing the position of the characteristic point in relation to a target position; and adjusting the carrier volume of the characteristic point, modifying the position of the characteristic point in order to bring the position of the characteristic point closer to the target position; the volume of the mobile phase injected per cycle being maintained higher than, or equal to, a minimum threshold and/or lower than, or equal to, a maximum threshold. The invention also relates to a computer program for carrying out the steps of such a method, to a storage medium on which such a program is recorded, and to a system comprising a processor coupled to a memory on which such a program is recorded.