Apparatus for field-flow fractionation

Apparatus for field-flow fractionation, comprising a separation channel, which, in addition to a first outlet for sample-containing solvent, comprises a second outlet for sample-free solvent, wherein

• the solvent is a liquid,
• the second outlet is arranged in a region of the separation channel from which sample-free solvent can be removed during elution simultaneously to removal of sample-containing solvent from the first outlet and wherein the second outlet is arranged upstream of the first outlet and opposite an accumulation wall of the separation channel, and
• a flow volume control device is arranged downstream of the second outlet,
• characterized in that the flow volume control device is a mass flow controller, and wherein the apparatus further comprises;
• a pump, a first flow volume splitting device, a first mass flow controller arranged downstream of the flow volume splitting device, a sample injection system, the separation channel with an inlet at a first end, the first outlet for sample-containing solvent at a second end, a connection for a cross-flow and the second outlet for sample-free solvent, which is arranged between the inlet and the first outlet, a second mass flow controller arranged downstream of the second outlet, a second flow volume splitting device, a first back-pressure element, a second back-pressure element, one or more detector(s) and a cross-flow control device, wherein
• a solvent stream generated by the pump is divided by means of the first flow volume splitting device into a first flow path and a second flow path,
• the first flow path leads via the first mass flow controller and the sample injection system to the inlet at the first end of the separation channel,
• the second flow path leads via the second back-pressure element to the second flow volume splitting device, which divides the solvent stream between the first outlet for sample-containing solvent at the second end of the separation channel and a third flow path, which leads via the first back-pressure element to the detector(s), and
• the cross-flow control device is connected with the separation channel via a fourth flow path and the connection for the cross-flow.