DE102013218818A1 - HPLC pump with active mixing element - Google Patents

Abstract

Shown is a pump (200) for high performance chromatography, which serves to bring a fluid to pressure and / or to convey. The pump (200) has a pumping chamber (220) and a - during operation of the pump (200) - in the pumping chamber (220) reciprocating element (230). The pump (200) further comprises an active mixing element (240) located in the pumping chamber (220) for mixing at least a portion of the fluid in the pumping chamber (220).

Description

BACKGROUND OF THE INVENTION

 The present invention relates to a pump for pressurizing and / or conveying a fluid, in particular for HPLC applications.

The mixing of liquids is a requirement in many technical fields and applications. For this purpose, mixing chambers are used in various embodiments and for various purposes, as for example US3934456A . JP11183457A . WO0151698A1 . WO02068954A1 . DE102008000112A1 . JP2009115056A or WO2011090188A1 is known.

 In High Performance Liquid Chromatography (HPLC), a liquid typically needs to have very tightly controlled flow rates (eg, in the range of nanoliters to milliliters per minute) and at a high pressure (typically 20-100 MPa, 200-1000 bar and moreover, until now about 200 MPa, 2000 bar), in which the compressibility of the liquid is felt, be promoted. For sample separation in an HPLC system, a mobile phase having a sample liquid with components to be separated in operation is forced through a stationary phase (such as a packing or filling of a chromatographic column) to thereby add different components of the sample separate. The composition of the mobile phase can be constant over time (isocratic mode) or varied (for example in the so-called gradient mode).

 Chromatography systems that combine, pressurize and dispense multiple fluids (especially liquids such as solvents) and deliver them as a mobile phase can cause artifacts in the mobile phase solvent composition due to insufficient mixing of the input fluids, negatively affecting chromatographic separation can affect. These artifacts can both have an absolute character, i. the mixture does not accurately match the set default, or a relative character, i. the mixture fluctuates, oscillates with the pumping frequency, or swirls with a shape of its own. Modern HPLC systems are optimized for fast and efficient operation under extremely high pressure. This, in turn, requires volume reduction while at the same time increasing composition accuracy requirements, so that simple passive solutions by increasing mixing volume are eliminated or at least detrimental to many applications because they represent a compromise acceptable only for limited applications. However, compositional disturbances in the mobile phase, especially at shorter separations, can lead to so-called retention-time jitter, even more so than flow fluctuations, e.g. Pump Ripple. Likewise, such compositional perturbations in the baseline of a downstream detector may become "visible" (e.g., in a chromatogram), and thus the evaluation, such as in a chromatogram. As identification or quantification interfere.

Pumps for HPLC that address various aspects of improved intermiscibility are described, for example, in U.S. Patent No. 4,308,347 US4595495A . US6997683B2 . US2012291531A1 . JPS61258975A , or US2013 / 0091935A1 ,

EPIPHANY

 It is an object of the present invention to improve the compositional accuracy of the mobile phase, especially for HPLC applications. The object is solved by the features of the independent claims. Advantageous embodiments are given in the dependent claims.

 A preferred embodiment of the present invention is a high performance chromatography pump. The pump is designed and configured to pressurize and / or convey a fluid. The pump has a pumping chamber and a reciprocating element which reciprocates in the pumping chamber during operation of the pump, that is to say reciprocated. Furthermore, the pump has an active mixing element located in the pumping chamber for mixing at least part of the fluid in the pumping chamber. By integrating the active mixing element directly into the pumping chamber, effective mixing of the fluid is already possible within the pumping chamber, so that the pump can deliver a well-mixed fluid. Further, to the pumping chamber external mixing chambers can be avoided or reduced. An additional volume which may additionally be required in the pumping chamber due to the provision of the active mixing element, compared to a pumping chamber without an active mixing element, can be compensated or at least relativised by eliminating other mixing volumes upstream or downstream of the pumping chamber. Also, such an active mixing element in the pumping chamber can at least partially utilize the volume which is at least temporarily "released" by the reciprocating element. It should also be taken into account that an improved mixing of the fluid already in the pumping chamber can also have a positive effect along the further flow path downstream of the pumping chamber.

Applications in HPLC typically rely on very good mixing of the mobile phase (fluid), as any deviations in the composition can be reflected in the result of the chromatographic separation and thus impair or even falsify the separation or measurement result. This applies in particular in the so-called gradient mode, in which the composition of the mobile phase is changed over time. A poor mixing of the mobile phase can here lead to a falsification of the chromatographic separation results, because in the gradient mode typically the mixture is done in situ and can not be used with pre-mixed fluids "from the bottle". The inventive provision of an active mixing element directly in the pumping chamber, the mixing of the fluid in the pumping chamber can be significantly improved, which can allow a significant improvement in the reproducibility of the chromatographic separation and / or the analytical evaluation.

 In a preferred embodiment of the pump, the active mixing element is configured to perform a rotational movement in the pumping chamber during operation of the pump. Such a rotational movement of the active mixing element can significantly improve the mixing of the fluid. In this case, the rotational movement of the active mixing element can take place relative to the reciprocating element and / or the pumping chamber, that is, for example, that the active mixing element rotates while the reciprocating element performs a longitudinal movement and / or the pumping chamber is kept still.

In a preferred embodiment, the active mixing element is configured so that it can be set in motion by a changing, in particular rotating, magnetic field. This allows in particular that the movement of the active mixing element from outside the pumping chamber can be transferred to the active mixing element, in particular by utilizing the magnetic or electromagnetic induction effect or magnetic forces. This also allows non-contact driving and / or controlling the movement of the active mixing element from outside the pumping chamber.

 In one embodiment, the active mixing element is at least partially made of a magnetic material, preferably iron and / or a permanent magnet, and can thereby be set in motion by a changing magnetic field. Embodiments of the active mixing element may be carried out according to the magnetic stirrers known and adequately described in the prior art, in which the stirring element is set in motion by a magnetic field applied from the outside. Such magnetic stirrers can be used appropriately and adapted to the special requirements of HPLC.

 In one embodiment, at least a portion of the active mixing element may be made of a conductive material, such as copper, gold, but also other metals, such that the induction forces arising in the variable (preferably rotating) magnetic field drive the active mixing element.

 In a preferred embodiment, the active mixing element has a wing element which, when in motion, can lead to increased mixing of the fluid. The wing element may in particular be a propeller or an impeller, as is well known and described in the prior art. In particular, the wing element can be "animated" into self-motions by splitting volume packets and displacing them ("split and recombine"), by moving volume packets, which are then "animated" by inertial forces (centrifugal force), and / or by exciting secondary flows take up more space than the movement space of the mixing element itself, lead to increased mixing of the fluid. The wing element may be designed so that at least parts of its surface are not aligned parallel but normal or oblique to their respective direction of movement during rotation. This may favor transmission of kinetic energy to the fluid.

In a preferred embodiment, the wing element on one or more wings, which are hinged. The term "hinged" can be understood in the sense that elastic or dynamic forces set up the wings as soon as the reciprocating element (for example, a piston within the pumping chamber) has traveled back a sufficient way. This can allow a very small "dead liquid" volume when the reciprocating element is at the front, eg close to the rotating active mixing element. However, the wings can set up for the mixing tasks, as soon as the reciprocating element releases stroke volume anyway. As a result, the "actual mixing chamber" within the pumping chamber does not necessarily represent an additional dead volume, but rather takes the (native) displacement of the reciprocating element (eg the piston), which is necessary anyway, as the working space. By folding the active mixing element or its parts can be achieved that in the common room of the folded active mixing element hardly or no free space for the fluid is present. This can be avoided that the active mixing element, for example by Cavities, depressions, etc. contributes to an increase in the dead volume in the pumping chamber. When unfolding the parts of the active mixing element his lounge and thus also active working or mixing space is greater if the volume released by the reciprocating element allows it.

 Likewise or alternatively, the wing member can be made reversibly deformable so that it can take a compact form, so that no considerable or only a reduced volume of fluid in the common space of the wing member is present.

 In a preferred embodiment, the active mixing element is configured to be set in motion by movement of the reciprocating element. Preferably, this movement is a reciprocating motion, that is, a reciprocating motion of the reciprocating element. Alternatively or additionally, the movement of the reciprocating member may be a rotational movement. As a result, a movement of the reciprocating element can be transferred to the active mixing element. By the direct transmission of the motion, the use of certain materials, e.g. are required for a magnetic or inductive movement of the active mixing element can be avoided. In addition, the use of a magnetic field can be avoided accordingly. This may have technical advantages, e.g. the material of the pumping chamber can shield the magnetic field or if the attachment of the magnetic field sources in the vicinity of the pumping chamber is technically problematic.

 In a preferred embodiment, the reciprocating element and / or the pumping chamber are / is configured such that, during operation, an at least occasionally high lateral flow is generated which sets the active mixing element in motion. The reciprocating element may be e.g. upon suction of the fluid through such punctiform high lateral flows to set the active mixing element in motion, which then in turn mixes the fluid in the pumping chamber.

 In a preferred embodiment, the reciprocating element has a recess, e.g. an inner hole, wherein the recess may be designed as a spiral. The active mixing element has a driver, which can engage in the recess. The active mixing element itself may preferably be held in a certain position, for example magnetically. The driver is configured to engage the recess in a particular area along the recess, but then disengage therefrom at a certain position, e.g. for example, when the driver has reached a point (e.g., outermost) along the recess. As the driver engages the recess, the reciprocating element transmits kinetic energy to the active mixing element. Upon release of the driver from the recess, the transmission of kinetic energy to the active mixing element is terminated, and the active mixing element then continues the transmitted motion. Thus, e.g. a rotary motion are transmitted to the active mixing element, upon reaching the release point of the driver releases the rotation (freewheel) and the reciprocating member is no longer coupled to the active mixing element at least with respect to the motion transmission. This decoupling of the motion transmission can preferably also be maintained for a return path of the reciprocating element. The active mixing element remains unchanged in its direction of movement, preferably its direction of rotation. According to embodiments, a relatively short "start-up time", which then follows a relatively long rotation period of the active mixing element, allow.

 In a preferred embodiment, the active mixing element comprises a vibrating vibrator, preferably a vibrating sonicator. Such a vibrator can produce a surface wave, which in turn "pulls" the fluid causing a stirring effect.

 In preferred embodiments, the active mixing element is at least on its surface of at least one of the following materials or comprises: ceramic, polymer such as a plastic, in particular polytetrafluoroethylene (PTFE), polyether ketone (PEEK), etc., metal such as a surface-coated metal, eg Diamond like carbon - DLC, sapphire, ruby, etc. Preferably, chemically or biologically inert or solvent-compatible materials may be used,

 Preferably, the pump is configured to bring the fluid to a pressure at which the compressibility of the fluid is appreciable, preferably a pressure greater than 500 bar or even more preferably greater than 1000 bar. In particular, the pump may be configured together with the reciprocating member so that the fluid is brought from substantially ambient pressure to the target pressure.

 In preferred embodiments, the reciprocating member is a piston or has a piston. Alternatively, or in combination, the reciprocating element may be a membrane or have a membrane. The piston itself or the pumping chamber can be designed as a bellows.

The reciprocating member is preferably configured to pressurize the fluid and / or to deliver the fluid.

The active mixing element may be configured and positioned in the pumping chamber such that fluids flowing in and out of the pumping chamber (ie, so to speak) flow through and / or such fluids still remaining from a previous cycle of the reciprocating element in the pumping chamber be located, recorded and mixed.

 The pumping chamber preferably has an inlet and an outlet. One or more fluids may be introduced into the pumping chamber through the inlet, and through the outlet, the mixed fluid exits the pumping chamber. The pumping chamber may be configured to receive one or more different fluids at the inlet and to provide at the outlet a pressurized, as homogeneous as possible mixture of the obtained fluids.

 The pumping chamber can - compared to a pumping chamber without active mixing element - be internally expanded geometrically, so that there is room for at least the moving active mixing element or in addition for a reaction space, which "mixes" the active mixing element. Optimized for certain applications, the space of movement of the reciprocating element can be offset (offset, or "variable stroke") so that method-specific a "desired" effective space is given.

 A preferred embodiment of the present invention relates to a high performance chromatography system having a mobile phase moving pump apparatus and a stationary phase for separating components of a sample liquid introduced into the mobile phase. In this case, the pumping device has the pump according to at least one of the preceding embodiments. The high performance chromatography system may further include one or more of the following features: a proportioning valve configured to supply one or more different fluids to an inlet of the pumping chamber; a Probeninjektor for introducing a sample liquid in the mobile phase; a detection device for detecting the separated components; a fractionator for preparatively collecting discrete components.

 The high-performance chromatography system may be a two-dimensional chromatography (2D-LC) system, in particular for the so-called "comprehensive 2D-LC", English: Comprehensive Chromatography. In the case of 2D LC, in many applications, it is particularly important to find the optimum compromise between the invested dead volume and the generated mixing quality.

 According to a further aspect, the invention relates to a method for mixing in a pump for high-performance chromatography. The pump is configured to pressurize a fluid. The pump has a pumping chamber in which a reciprocating element and an active mixing element are located. In the operating state of the pump, the reciprocating element moves back and forth in the pumping chamber. The method comprises mixing at least a portion of the fluid in the pumping chamber by means of the active mixing element. The method according to the invention proves to be advantageous, in particular in a gradient mode, since a plurality of fluids flowing into the pump on the inlet side are to be mixed, whereby the ratios of the inflowing fluids to one another, that is to say, are different. whose relative concentrations change with each other over time. If, due to the design, the pump has a serial interconnection of individual pumping chambers, at least one of the pumping chambers being connected downstream from the mixing point of the eluent portions or the eluent portions being brought together and mixing in a pumping chamber, the at least downstreammost pumping chamber acquires a modified one in each pumping cycle in the gradient mode fluid composition. ". Also in this case, it is advantageous to mix this new portion with the remaining content (mixture of previous portions) homogeneously. A good mixing of the fluid supplied by the pump on the output side has a particularly good effect on the reproducibility and the measurement and separation accuracy of the chromatographic separation.

 A high performance chromatography system according to the present invention comprises a mobile phase moving pump apparatus, a stationary phase for separating components of a sample liquid introduced into the mobile phase, and a valve located in a mobile phase flow path. The pump device may have one or more pumps according to the aforementioned embodiments. The high performance chromatography system may further include a sample injector for introducing the sample liquid into the mobile phase, a detector for detecting separated components of the sample liquid, and / or a fractionating device for dispensing separate components of the sample liquid.

Embodiments of the present invention may be practiced on the basis of many of the known HPLC systems, such as the Agilent Infinity Series 1290, 1260, 1220 and 1200 of the Applicant Agilent Technologies, Inc., see www.agilent.com.

 As a mobile phase (or eluent) can be a pure solvent or a mixture of different solvents, which is given in the storage bottle or sucked from different storage bottles, are used. The mobile phase can be chosen to optimize or minimize for the purpose the retention of components of interest and / or the amount of mobile phase for conducting the chromatography. The mobile phase can also be chosen to effectively separate certain components. It may be an organic solvent such as e.g. Methanol or acetonitrile, which is often diluted with water. For a gradient mode for the "reversed phase" mode, water and an organic solvent (or other solvents common in HPLC) are often varied in their mixing ratio over time. Also common is the IEC application with salt or buffer gradients, or the controlled addition of modifiers, e.g. small amounts of acids.

 The or one of the above-described methods may be wholly or partially supported by software when running on a data processing system such as a computer or workstation. The software may or may not be stored on a data carrier or supplied from the worldwide network (e.g., the Internet).

DESCRIPTION OF THE DRAWINGS

 The invention will be further explained below with reference to the drawings, wherein like reference numerals refer to the same or functionally identical or similar features.

1 shows a liquid separation system 10 according to embodiments of the present invention, as used for example in HPLC.

2 shows a schematic sectional view of an embodiment of a pump 200 ,

The 3A - 3C exemplify exemplary embodiments of the wing element 280 is

4 and 5 represent embodiments of the active mixing element 240 represents.

In detail shows 1 a general representation of a liquid separation system 10 , A pumping device 20 receives a mobile phase from a solvent supply 25 typically via a degasser 27 , which degasses the mobile phase and thus reduces the amount of dissolved gases in the mobile phase. The pumping device 20 drives the mobile phase through a separation device 30 (like a chromatographic column), which has a stationary phase. A sample device (or sample injector) 40 can be between the pumping device 20 and the separation device 30 be provided to bring a sample fluid in the mobile phase. The stationary phase of the separation device 30 is adapted to separate components of the sample fluid. A detector 50 Detects separated components of the sample fluid, and a fractionator 60 can be provided for dispensing the separated components.

The mobile phase can consist of only one solvent or of a mixture of different solvents. Mixing can be done at low pressure and before the pumping device 20 done so that the pumping device 20 already transported the mixed solvent as a mobile phase. Alternatively, the pump may consist of individual pumping units, each pumping unit conveying a solvent or a solvent mixture, so that the mixture of the mobile phase (as then the separation device 30 experiences) under high pressure and after the pumping device 20 he follows. The composition (desired mixture) of the mobile phase can be kept constant over time (isocratic mode) or varied over time in a so-called gradient mode.

A data processing unit 70 , which may be a conventional PC or workstation, may be attached to one or more of the devices in the fluid separation system, as indicated by the dashed arrows 10 coupled to receive information and / or to control the operation of the system or individual components therein.

2 shows a schematic sectional view of an embodiment of a pump 200 , In the 1 illustrated pumping device 20 can one or more of these pumps 200 , preferably serially coupled to each other, as is well known and described in the art in the field of high performance chromatography. The pump 200 has an inlet 210 who is in a pumping chamber 220 opens. In the pumping chamber 220 is a reciprocating element in this embodiment 230 , here a piston, by reciprocating (ie, reciprocating) within the pumping chamber 220 through the inlet 210 inflowing fluids sucks on the one hand and brings to the other on pressure. Instead of in 2 represented piston as a reciprocating element 230 Accordingly, a membrane can also be used, as is likewise sufficiently known in the prior art.

The pump 200 points in her pumping chamber 220 an active mixing element 240 on, that for mixing at least a part of itself in the pumping chamber 220 configured fluid is configured.

The pumping chamber 220 also has an outlet 250 on to the pressurized fluid from the pumping chamber 220 to flow out, ie to promote the liquid. In the embodiment according to 2 gets the inlet 210 one or more fluids via a proportional valve 255 , The proportional valve 255 Again, here is coupled with 4 solvents A, B, C and D and can one or more of these solvents to the inlet 210 couple, so by a corresponding suction movement of the piston 230 (in the embodiment according to 2 a movement to the left) or the via the proportional valve 255 coupled solvent in the pump room 220 be sucked in. It is clear that the proportional valve 255 also less or more than the one in 2 shown solvent with the pump 200 can connect.

In 2 schematically corresponding valves are shown, each to the inlet 210 as well as the outlet 250 are fluidically coupled, for example, both an intake of the fluids in the pumping chamber 220 (eg by a movement of the piston 230 to the left in the embodiment according to 2 ) and / or pressurizing and expelling the pressurized fluid (eg, by movement of the piston 230 to the right in 2 ) or even to facilitate it. Such valves as well as other details and configurations, for example for mixing and proportioning solvents, are described, inter alia, in the aforementioned WO2013 / 013717A2 by the same Applicant and the same inventor, and the content of this document is incorporated by reference.

2 further shows a seal 260 for sealing the pumping chamber 220 together with the corresponding part of the piston 230 in the pumping chamber 220 sufficient and in conjunction with the seal 260 stands. The pumping chamber 220 along with the inlet 210 and the outlet 250 may be located in a (not shown) pump head, for example, as a correspondingly machined metal block into which the pumping chamber 220 , the inlet 210 and the outlet 250 For example, could be executed by drilling molded.

A return mechanism 270 , shown schematically here by an arrow, is provided around the piston 230 to move back to an original position, after this by a (in 2 not shown) drive was deflected.

This in 2 schematically illustrated active mixing element 240 is here designed so that it is in an operating condition of the pump 200 So if the piston 230 moved back and forth, performs a rotational movement and thus the or in the pumping chamber 220 located fluids, or at least the part thereof, which is within reach of the active mixing element 240 is located, mixed. The rotational movement of the active mixing element 240 takes place in 2 relative to the reciprocal element 230 and also to the pumping chamber 220 ,

By attaching or integrating the active mixing element 240 directly in the pumping chamber 220 experiences the fluid to be mixed already at the entrance and then within the pumping chamber 220 an at least intensified mixing, so that optionally further mixing elements, such as one or more to the pumping chamber 220 external mixing chambers, are no longer necessary. The term "external to the pumping chamber 220 "Should be understood to refer to the space along the river path that flows downstream to the outlet 250 lies. The pumping chamber 220 in turn, can be considered the geometric space between the inlet 210 and the outlet 250 be understood.

The introduction of the active mixing element 240 can in many cases increase the volume of the pumping chamber 220 versus an embodiment without an active mixing element 240 mean. However, this increased volume may be justified by the resulting improved mixing. In many applications, however, this additional volume will also allow a reduction in other volumes provided for improved mixing, so that overall, it is not absolutely necessary to increase the dead volume by introducing the active mixing element 240 into the pumping chamber 220 must result.

In the embodiment according to 2 consists of the active mixing element 240 from a wing element 280 and one external to the pumping chamber 220 attached drive element 290 , The wing element 280 has in this embodiment, a magnetic material, such as an iron core and / or a permanent magnet, by one of the drive element 290 generated changing magnetic field can be brought into motion. For this purpose, embodiments which are known in the prior art with respect to stirring elements (as used, for example, in the chemical industry) can be used.

The wing element 280 points in the in 2 illustrated embodiment, three wings, which are designed so that upon movement of the wing member 280 an improved mixing he follows. However, the wing element needs 280 not necessarily have individual wings and can also be performed for example by a rod element, as is known from many stirrers. A few exemplary embodiments of the wing element 280 be in the 3 shown.

The drive element 290 For example, it may itself be or include a magnet that is rotated by a drive, for example. The drive element 290 may also or alternatively also have one or more magnetic coils, which are then electrically controlled so that a correspondingly variable magnetic field is generated.

The 3A - 3C exemplify exemplary embodiments of the wing element 280 represents. 3A shows a wing disc, which is designed so that a correspondingly shaped piston can dive into the center. Thus, act a variety of wings 284 also "around the piston". Are the wings 284 in the embodiment according to 3A itself elastic or movable (tiltable or hinged) to the base disc 285 attached so that they are in one to the disc 285 pressed condition does not exceed the base of the disc 285 protrude, and in a erect condition, for example, at a sharp angle to the disc 285 stand, so this structure is a hinged mixing element described above 280 represents.

3B further shows an embodiment which, when rotated, forces radial flow. This "sucked" in the center and creates a flow that runs like a roll on the wall long and back in the center.

3C represents an embodiment of the wing element 280 As a result, a particularly small dead volume can be made possible because the wings occupy only a very small space. A correspondingly shaped piston, which carries a funnel (a hole) on the front side, can now approach very close and exploit the volume.

4 represents an embodiment of the active mixing element 240 represented by movement of the reciprocal element 230 is set in motion. The reciprocating element 230 , here a piston, in combination with the pumping chamber 220 (which in the sake of clarity in 4 not shown) is in this case configured so that there is an at least selectively high lateral flow during operation 277 generates the active mixing element 240 set in motion. The piston 230 the active mixing element can be aspirated or displaced by punctually high lateral flow 240 set in motion, which in turn in the pumping chamber 220 the fluid is mixed. In the illustrated embodiment, the mixing element 240 through the effect of the lateral flow 277 on a "turbine part" 244 of the mixing element 240 driven, whereby a thus coupled stirrer part 266 a mixing in other parts of the pumping chamber 220 causes. It is understood that the designs of the stirrer part 266 and the turbine part 244 can be varied, with the turbine part 244 should each be placed in the region of high flow velocities (as shown here in the gap between the reciprocating element 230 and the wall of the pumping chamber 220 or alternatively, for example, in the vicinity of the inlet bore of the pumping chamber) and by its movement further parts of the mixing element 240 set in motion in the region of slow flow or insufficient mixing.

In another, in 5 shown embodiment of the active mixing element 240 points the piston 230 a recess 400 on, for example, an inner hole, which is designed as a spiral. The active mixing element 240 has a driver 410 on, in the recess 400 intervenes. In addition, the mixing element 240 by means of a freewheel device to the driver 410 be coupled.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 3,934,456 A [0002]
• JP 11183457 A [0002]
• WO 0151698 A1 [0002]
• WO 02068954 A1 [0002]
• DE 102008000112 A1 [0002]
• JP 2009115056 A [0002]
• WO 2011090188 A1 [0002]
• US 4595495 A [0005]
• US 6997683 B2 [0005]
• US 2012291531 A1 [0005]
• JP 61258975 A [0005]
• US 2013/0091935 A1 [0005]
• WO 2013/013717 A2 [0045]

Claims (15)

A pump ( 200 ), for high performance chromatography to pressurize and / or convey a fluid, comprising: a pumping chamber ( 220 ) and one - during operation of the pump ( 200 ) - in the pumping chamber ( 220 ) reciprocating element ( 230 ) characterized by being in the pumping chamber ( 220 ) active mixing element ( 240 ) for mixing at least a part of itself in the pumping chamber ( 220 ) located fluid. The pump ( 200 ) according to claim 1, characterized in that the active mixing element ( 240 ) is configured to operate during pump operation ( 200 ) a rotational movement in the pumping chamber ( 220 ). The pump ( 200 ) according to the preceding claim, characterized in that the rotational movement of the active mixing element ( 240 ) relative to the reciprocal element ( 230 ) and / or the pumping chamber ( 220 ). The pump ( 200 ) according to one of the preceding claims, characterized in that the active mixing element ( 240 ) is configured so that it can be set in motion by a changing magnetic field. [Magnetic Stirrer] The pump ( 200 ) according to the preceding claim, having at least one of the following features: the active mixing element ( 240 ) is at least partially made of a magnetic material, preferably iron and / or a permanent magnet, and can thereby be set in motion by the changing magnetic field; the active mixing element ( 240 ) is at least partially made of electrically conductive material, preferably copper, and can thereby be set in motion by the action of induction currents in the changing magnetic field. The pump ( 200 ) according to one of the preceding claims, characterized in that the active mixing element ( 240 ) has a wing element, preferably a propeller or an impeller, which, in motion, leads to increased mixing of the fluid. The pump ( 200 ) according to the preceding claim, characterized in that the wing element has one or more wings which are hinged. The pump ( 200 ) according to one of the preceding claims, characterized in that the active mixing element ( 240 ) is configured to move by a movement, preferably a reciprocating motion, of the reciprocating element ( 230 ) is set in motion. The pump ( 200 ) according to the preceding claim, characterized in that the reciprocating element ( 230 ) is configured in such a way that it generates an at least occasionally high lateral flow during operation, which the active mixing element ( 240 ) set in motion. The pump ( 200 ) according to one of the preceding claims, characterized in that the active mixing element ( 240 ) has a vibrating vibrator, preferably a vibrating transducer. The pump ( 200 ) according to one of the preceding claims, characterized in that the active mixing element ( 240 ) consists at least on its surface of at least one of the following materials: ceramic, polymer, in particular polytetrafluoroethylene, polyether ketone, metal, sapphire, ruby. The pump ( 200 ) according to one of the preceding claims, with at least one of the features: the pump ( 200 ) is configured to bring the fluid to a pressure at which the compressibility of the fluid is appreciable, preferably a pressure greater than 500 bar or more preferably greater than 1000 bar; the reciprocal element ( 230 ) is or has a piston; the reciprocal element ( 230 ) is or has a membrane; the reciprocal element ( 230 ) is configured to pressurize the fluid; the active mixing element ( 240 ) is configured and in the pumping chamber ( 220 ) such that fluids entering the pumping chamber ( 220 ) and / or those fluids which are still distinct from a preceding cycle of the reciprocal element ( 230 ) in the pumping chamber ( 220 ), recorded and mixed; the pumping chamber ( 220 ) has an inlet ( 210 ) and an outlet ( 250 ) on; the pumping chamber ( 220 ) is configured to be connected to an inlet ( 210 ) receives one or more different fluids and at an outlet ( 250 ) provides a pressurized mixture of the obtained fluids. A high performance chromatography system ( 10 ), comprising: a pump device ( 20 ) for moving a mobile phase, wherein the pumping device ( 20 ) the pump ( 200 ) according to one of the preceding claims, and a stationary phase ( 30 ) for separating components of a sample liquid introduced into the mobile phase. The High Performance Chromatography System ( 10 ) according to the preceding claim, comprising at least one of the 280 features: a proportioning valve configured to receive one or more different fluids at an inlet ( 210 ) of the pumping chamber ( 220 ); a sample injector ( 40 ) for introducing a sample liquid into the mobile phase; a detection device ( 60 ) for detecting the separated components; a fractionator ( 80 ) for preparatively collecting separated components; the high performance chromatography system ( 10 ) is a two-dimensional chromatographic system. A method of mixing in a pump ( 200 ) for high performance chromatography, the pump ( 200 ) is configured to pressurize a fluid and a pumping chamber ( 220 ), a - during operation of the pump ( 200 ) - in the pumping chamber ( 220 ) reciprocating element ( 230 ) and in the pumping chamber ( 220 ) active mixing element ( 240 ), the method comprising mixing at least a portion of the material in the pumping chamber ( 220 ) by means of the active mixing element ( 240 ).

Images