A chromatographic column assembly is described, comprising a channel and a flow inducer. The channel comprises an inlet for receiving a sample liquid and an outlet, and is adapted for separating the sample liquid into components when the sample liquid flows through the channel in an axial direction from the inlet to the outlet. The flow inducer is adapted for controllably inducing, when the sample fluid is flowing through the channel, a motion of the sample liquid in the channel in a plane substantially orthogonal to the axial direction.