Device for the separation of magnetic or paramagnetic microparticles and the elution of an analyte adsorbed on said particles, the device being a liquid system comprising a first and a second inlet (10, 20) for a first and a second liquid mobile phase (65, 75), wherein the mobile phases are in a liquid state of aggregation, means for making fluidic connections, a switching unit for producing two different fluid connecting states, the switching unit having three entry ports (E1, E2, E3) and three exit ports (A1, A2, A3), magnetic or paramagnetic microparticles and liquid sample material, at least one pressure-generating means, an injection device, two storage containers (60, 70) for a first and a second mobile phase (65, 75), a collecting vessel, an outlet, and an extractor, a1) wherein the extractor comprises (i) an entry port, (ii) an exit port, (iii) a section between said entry port and said exit port, the section comprising a fluid connecting line, and (iv) a means capable of temporarily applying a local magnetic field to the fluid connecting line in the section, b1) wherein the first inlet is designed such that the first mobile phase can be fed under pressure from the first storage container to the LS via a fluidic connection; b2) wherein the first inlet is additionally fluidically connected to an injection device, the injection device being designed such that it allows a mixture of liquid sample material and said magnetic or paramagnetic microparticles suspended therein to be introduced into the first mobile phase that was introduced through the inlet; b3) wherein the second inlet is designed such that the second mobile phase can be fed under pressure from the second storage container to the LS via a fluidic connection; b4) wherein the first inlet is connected to the first entry port of the switching unit and the second inlet is fluidically connected to the second entry port of the switching unit; c1) wherein the entry port of the extractor is fluidically connected to the first exit port of the switching unit, and the exit port of the extractor is fluidically connected to the third entry port of the switching unit; c2) the second exit port of the switching unit is the outlet or is fluidically connected to the outlet; c3) the third exit port of the switching unit is fluidically connected to the collecting vessel; and d1) the switching unit is suitable in a first connecting state for fluidically connecting E1 and A1, E2 and A2 as well as E3 and A3 and in the second connecting state it is suitable for fluidically connecting E2 and A1, E3 and A2 as well as E1 and A3, and the device being further characterized in that e1) the means comprises a rotatable circular disk with a controllable actuator capable of adjusting the disk, by way of rotation, in a first and a second position; e2) a fraction of the circumference of the disk is located in proximity to the fluid connecting line of the section; e3) in a segment of the disk one or more permanent magnets are attached; e4) in a first position of the disk the magnetic field of the one or more magnets is applied to the fluid connecting line of the section; and e5) in a second position the magnetic field applied to the fluid connecting line of the section is reduced. a1) wherein the extractor comprises (i) an entry port, (ii) an exit port, (iii) a section between said entry port and said exit port, the section comprising a fluid connecting line, and (iv) a means capable of temporarily applying a local magnetic field to the fluid connecting line in the section, b1) wherein the first inlet is designed such that the first mobile phase can be fed under pressure from the first storage container to the LS via a fluidic connection; b2) wherein the first inlet is additionally fluidically connected to an injection device, the injection device being designed such that it allows a mixture of liquid sample material and said magnetic or paramagnetic microparticles suspended therein to be introduced into the first mobile phase that was introduced through the inlet; b3) wherein the second inlet is designed such that the second mobile phase can be fed under pressure from the second storage container to the LS via a fluidic connection; b4) wherein the first inlet is connected to the first entry port of the switching unit and the second inlet is fluidically connected to the second entry port of the switching unit; c1) wherein the entry port of the extractor is fluidically connected to the first exit port of the switching unit, and the exit port of the extractor is fluidically connected to the third entry port of the switching unit; c2) the second exit port of the switching unit is the outlet or is fluidically connected to the outlet; c3) the third exit port of the switching unit is fluidically connected to the collecting vessel; and d1) the switching unit is suitable in a first connecting state for fluidically connecting E1 and A1, E2 and A2 as well as E3 and A3 and in the second connecting state it is suitable for fluidically connecting E2 and A1, E3 and A2 as well as E1 and A3, e1) the means comprises a rotatable circular disk with a controllable actuator capable of adjusting the disk, by way of rotation, in a first and a second position; e2) a fraction of the circumference of the disk is located in proximity to the fluid connecting line of the section; e3) in a segment of the disk one or more permanent magnets are attached; e4) in a first position of the disk the magnetic field of the one or more magnets is applied to the fluid connecting line of the section; and e5) in a second position the magnetic field applied to the fluid connecting line of the section is reduced.