| 摘要 |
Described is a device for field flow fractionation, having a sensor (36) for determining the presence of particles in a carrier liquid, having at least one substantially closed elongate duct (20; 50) which has a first end (20a; 50a) with a first port (22; 52) and a second end (20b; 50b) with a second port (24; 54) and the wall of which has at least one portion which extends in the longitudinal direction of the duct (20; 50) and which is impermeable to the particles and permeable to the carrier liquid, having a pump (2) which has an inlet and an outlet (2a) and which is provided for delivering the carrier liquid, having a first liquid path (6) which connects the outlet (2a) of the pump (2) to the first port (22; 52) of the duct (20; 50), having a second liquid path (28) which connects the second port (24; 54) of the duct (20; 54) to a first switching means (30) by which the second liquid path (28) can be connected, in a first switching position, to the outlet (2a) of the pump (2), and in a second switching position, to the sensor (36), having an injection device (16) which is arranged in the first liquid path (6) and which is provided for injecting a sample containing particles into the carrier liquid flowing through the first liquid path (6), and having a mass flow splitting device (8, 10, 12) which splits up the mass flow delivered by the pump (2) between the first liquid path (6) and the second liquid path (28) in a predefined split ratio when the first switching means (30) is in the first switching position and which has a first mass flow control device, which first mass flow control device is arranged in the first liquid path (6) and is provided for controlling the mass flow of the carrier liquid in the first liquid path (6) and has a first valve (8) for adjusting the mass flow of the carrier liquid in the first liquid path (6), characterized in that the first mass flow control device has a first measurement device (12) for measuring the mass flow of the carrier liquid, the valve (8) is arranged upstream of said first measurement device (12) and is provided for controlling the mass flow of the carrier liquid in the first liquid path (6) taking into consideration the measurement result from the first measurement device (12), and the pump (2) is provided for delivering the carrier liquid with a precisely dosable mass flow. Also described is a method for carrying out field flow fractionation by means of the device specified above. |
