A circuit synchronizes the actuation of multi-dimensional separating valves with a system clock also coupled to a data acquisition circuit such that signals from a detector are synchronized and no signal information is lost. The system comprises an acquisition clock coupled to a data acquisition logic system and to a modulator valve control. The modulator valve control is, in turn, coupled to a multi-dimensional separation technique valve unit for controlling the valves for introduction of the eluant from a first separation column to a second, faster column in synchronism with acquisition of data by a detector.