Patent Application
20170131245
The present invention relates to a secondary stage sample separation device, a primary stage sample separation device, a sample separation system, and a method of carrying out a multiple stage separation of a fluidic sample.
In liquid chromatography, a fluidic sample and an eluent (liquid mobile phase) may be pumped through conduits and a column in which separation of sample components takes place. The column may comprise a material which is capable of separating different components of the fluidic sample. Such a packing material, so-called beads which may comprise silica gel, may be filled into a column tube which may be connected to other elements (like a sampler, a detector) by conduits.
Background art is disclosed in U.S. Pat. No. 5,738,133, US 2010/277722, JP 2014095613, WO 2012/149956, U.S. Pat. No. 4,024,061, US 2003/087454, and US 2012/240666.
Two-dimensional separation of a fluidic sample denotes a separation technique in which a first separation procedure in a first separation unit is performed to separate a fluidic sample into a plurality of fractions, and in which a subsequent second separation procedure in a second separation unit is performed to further separate at least one of the plurality of fractions into sub-fractions. Two-dimensional liquid chromatography (2D LC) may combine two liquid chromatography separation techniques and plot the time dependency of detection events along two orthogonal time axes.
Two-dimensional liquid chromatography apparatuses are powerful, but may also be complex in construction, large in size, and have limited flexibility.
It is an object of the invention to enable multiple stage or multiple dimension sample separation with a high degree of flexibility. The object is solved by the independent claims. Further embodiments are shown by the dependent claims.
According to an exemplary embodiment of the present invention, a (for instance mobile, in particular configured to be spatially movable or displaceable, more particularly configured to be transportable by rolling) secondary stage sample separation device for separating at least a portion of a fluidic sample (wherein a fluid may be a liquid and/or a gas, optionally comprising solid particles) is provided, wherein the secondary stage sample separation device comprises a fluidic interface configured for forming a detachable (i.e. connectable or disconnectable by a user, for instance by plugging any primary stage sample separation device to the fluidic interface for connecting the devices and for unplugging the primary stage sample separation device from the fluidic interface for disconnecting the devices; the attaching and detaching may be accomplished by the user by hand or using a tool) fluidic coupling between a primary stage sample separation device and the secondary separation device so that the fluidic sample separated by the primary stage sample separation device is fluidically suppliable to the secondary stage sample separation device via the fluidic interface for further separation, wherein the secondary stage sample separation device is configured for further separating (i.e. for performing a further separation of at least a portion of the fluidic sample which has already been pre-separated by the primary stage sample separation device) at least a portion of the supplied fluidic sample independent (or irrespective) of a flow rate of the fluidic sample supplied from the primary stage sample separation device at the fluidic interface (i.e. the two values of the flow rate according to which the two devices operate do not need to be matched prior to their coupling via the fluidic interface, but in contrast to this the secondary stage sample separation device can be configured to adapt its operation to any flow rate value provided by a presently connected primary stage sample separation device).
According to another exemplary embodiment of the present invention, a secondary stage sample separation device for separating at least a portion of a fluidic sample is provided, wherein the secondary stage sample separation device comprises a fluidic interface configured for forming a (for instance detachable) fluidic coupling between a primary stage sample separation device and the secondary separation device so that the fluidic sample separated by the primary stage sample separation device may be supplying a fluid to the secondary stage sample separation device via the fluidic interface for further separation, and a pressure reduction mechanism configured for reducing pressure at the fluidic interface at least in the event of an overpressure or of an excessive pressure increase or a pressure fluctuation.
According to another exemplary embodiment of the present invention, a primary stage sample separation device for separating at least a portion of a fluidic sample is provided, wherein the primary stage sample separation device comprises a fluidic outlet at which the separated fluidic sample is provided and which is fluidically coupled or suitable for being fluidically coupled, in particular detachably fluidically coupled, to a fluidic interface of a secondary sample separation device so that the fluidic sample separated by the primary stage sample separation device may be supplying a fluid to the secondary stage sample separation device via the fluidic interface for further separation, and a pressure reduction mechanism configured for reducing pressure in the primary stage sample separation device at least in the event of an overpressure or of an excessive pressure increase or a pressure fluctuation introduced by an action of the secondary stage sample separation device.
According to another exemplary embodiment of the present invention, a sample separation system for carrying out a multiple stage separation of a fluidic sample is provided, wherein the sample separation system comprises a (in particular static, more particularly configured to be spatially fixed or immobile, still more particularly installed at a spatially fixed position) primary stage sample separation device (which may optionally have the above mentioned features) for separating a fluidic sample, and a (in particular mobile) secondary stage sample separation device (which may optionally have the above mentioned features) fluidically coupleable or coupled (in particular detachably fluidically coupleable or actually detachably fluidically coupled) to the primary stage sample separation device via the fluidic interface and configured for further separating at least a portion of the fluidic sample supplied and separated by the primary stage sample separation device.
According to another exemplary embodiment of the present invention, a method of carrying out a multiple stage separation of a fluidic sample is provided, wherein the method comprises (optionally moving a mobile secondary stage sample separation device towards a static primary stage sample separation device) fluidically coupling a primary stage sample separation device to a secondary stage sample separation device (in particular a secondary stage sample separation device having the above mentioned features) by attaching a fluid handling interface (hereafter also referred to as “fluidic interface”) of the secondary stage sample separation device to a fluid outlet (in particular a waste conduit) of the primary stage sample separation device, and carrying out a primary stage separation of the fluidic sample. The secondary stage sample separation device carries out a secondary stage separation of at least a portion of the fluidic sample by further separating at least a portion of the separated fluidic sample provided at the fluidic interface. At least after passing the said portion of the fluidic sample into the secondary stage sample separation device or after carrying out the primary stage separation and/or the secondary stage separation or desired series of the primary stage separations and/or the secondary stage separations, the fluidic interface is detached from the primary stage sample separation device to thereby fluidically decouple the secondary stage sample separation device from the primary stage sample separation device (and optionally, after the detaching, the mobile secondary stage sample separation device may be moved away from the static primary stage sample separation device (in particular, the mobile secondary stage sample separation device may be moved towards another static primary stage sample separation device for carrying out another multiple stage separation of another fluidic sample by repeating the procedures of fluidically coupling, primary stage separating, and secondary stage separating by means of the mobile secondary stage sample separation device and the other static primary stage sample separation device)). Optionally, at least in the event of an overpressure introduced by an action of the secondary stage sample separation device, the method may further comprise reducing pressure for preventing a detector of the primary stage sample separation device detecting the separated fluidic sample from being exposed to the excess or overpressure.
In the context of this application, the term “fluidic sample” may particularly denote any liquid and/or gaseous medium, optionally including also solid particles, which is to be analyzed. Such a fluidic sample may comprise a plurality of fractions of molecules or particles which shall be separated, for instance small mass molecules or large mass biomolecules such as proteins. Since separation of a fluidic sample into fractions involves a certain separation criterion (such as mass, volume, chemical properties, etc.) according to which a separation is carried out, each separated fraction may be further separated by another separation criterion (such as mass, volume, chemical properties, etc.) or finer separated by the first separation criterion (under improved conditions), thereby splitting up or separating a separate fraction into a plurality of sub-fractions.
In the context of this application, the term “sample separation device” may particularly denote any apparatus which is capable of separating different fractions of a fluidic sample by applying a certain separation technique. Particularly, two separation units may be provided in such a sample separation system when being configured for a two-dimensional separation. This means that the sample is first separated in accordance with a first separation criterion, and at least one or some of the fractions resulting from the first separation are subsequently separated in accordance with a second, different, separation criterion ore more finely separated in accordance with the first separation criterion. The term “separation unit” may particularly denote a fluidic member through which a fluidic sample is transferred and which is configured so that, upon conducting the fluidic sample through the separation unit, the fluidic sample will be separated into different groups of molecules or particles (called fractions or sub-fractions, respectively). An example for a separation unit is a liquid chromatography column which is capable of trapping or retarding and selectively releasing different fractions of the fluidic sample.
According to an exemplary embodiment of the invention, a primary stage sample separation apparatus is provided which is capable of standalone operation (i.e. it is configured to separate samples, detect their constituents or components and provide the relevant separation data e.g. in a form of chromatogram), and a secondary stage sample separation apparatus is provided which has a detachable fluidic interface at its fluidic inlet. Hence, it can be simply attached to or detached from a presently used primary stage sample separation device which thereby can be reversibly extended to a multistage sample separation system. Such a detachable fluidic interface may be simply plugged by a user to a fluidic outlet of the primary stage sample separation device. After such a temporarily established ad hoc multistage sample separation system has been used for a user-defined non-permanent multi-dimensional fluid separation application and the application has been finished, the primary stage sample separation device and the secondary sample separation device may be again separated from one another by a simple unplugging operation at the fluidic interface. Then, the primary stage sample separation device is ready for a new standalone separation of a further fluidic sample, and the secondary stage sample separation device is ready to be connected to another primary stage sample separation device via the multipurpose fluidic interface.
When providing such a universally usable secondary stage sample separation device, there is the challenge that it may happen that the secondary stage sample separation device, at least from time to time, eventually only for a short span of time (<1sec), generates an excess pressure or overpressure or a flow decrease or interruption which can be undesirably fed back via the fluidic interface to the primary stage sample separation device. In particular, such overpressure periods may be generated by a modulator valve of the secondary stage sample separation device when the modulator valve performs a switch operation which temporarily removes or decreases the ability of the secondary stage sample separation device to continue reception of fluidic sample which is continuously fed by the primary stage sample separation device via the fluidic interface to the secondary stage sample separation device. During such fluid acceptance interruption periods, in which the secondary stage sample separation device is not able to accept new continuously fed fluidic sample, there is the risk that the fluid flow is blocked in the inlet of the secondary stage sample separation device which generates an overpressure. This overpressure, in turn, affects the outlet section of the primary stage sample separation device, in particular a detector thereof configured for detecting fractions of the fluidic sample separated in the primary stage sample separation device. On the one hand, in extreme cases such an overpressure may result in the breakage of the detector. On the other hand, such an overpressure may deteriorate quality of the detection data generated by the detector and being indicative of the result of the primary sample separation. An exemplary embodiment overcomes or at least decreases this drawback by providing a pressure reduction mechanism in the secondary stage sample separation device and/or in the primary stage sample separation device which, in the event of such an overpressure, self-sufficiently damps or reduces this pressure so as to prevent undesired deterioration of the functionality of the detector of the primary stage sample separation device even during fluid acceptance interruption periods. It is particularly preferred when such a pressure reduction mechanism is implemented in the inlet section of the secondary stage sample separation device, because this then allows to flexibly combine the universal secondary stage sample separation device with pressure reduction mechanism with any conventional primary stage sample separation device.
When providing such a universally usable secondary stage sample separation device, there is the further challenge that different primary stage sample separation devices to be connected via the fluidic interface to the secondary stage sample separation device are usually operated autonomously so that they may have different regimes in terms of a mobile phase flow rate values used for separating the fluidic samples. In order to enable the secondary stage sample separation device to be used with different primary stage sample separation devices operating under different flow rate regimes, the secondary stage sample separation apparatus can have a corresponding provision at the fluidic interface to cope with substantially any desired flow rate. Thus, a highly flexibly operable secondary stage sample separation apparatus is provided, which allows to extend substantially any primary stage sample separation device to a two, or more generally multiple, stage sample separation system. Also retrofitting a primary stage sample separation device into a multi-dimensional sample separation system is possible by adding this secondary stage sample separation device.
In the following, further exemplary embodiments of the secondary stage sample separation device, the primary stage sample separation device, the sample separation system, and the method will be explained. Generally, any of the embodiments described herein with regard to the pressure reduction mechanism in the secondary stage sample separation device is also applicable to the primary stage sample separation device however at a position between the detector and its fluidic outlet used as fluidic interface to the secondary stage sample separation device.
The term “at least in the event of an overpressure” denotes that the pressure reduction mechanism may (or may not) also act (or be active) even if there is no overpressure.
According to an exemplary embodiment of the invention, the pressure reduction mechanism is configured for preventing the overpressure from impacting the primary stage sample separation device, in particular a detector of the primary stage sample separation device. Thus, any feedback or propagation of an overpressure induced by the secondary stage sample separation device (which is not preferred in the secondary stage sample separation device as well, but which generates more severe effects in the primary stage rather than in the secondary stage) to the primary stage sample separation device can be suppressed. Such an overpressure may be highly harmful in particular for the detector (such as a flow cell detector, in particular a fluorescence-based flow cell detector) at a downstream position of the primary stage sample separation device.
According to an exemplary embodiment of the invention, the pressure reduction mechanism is configured for reducing pressure at the fluidic interface in the event of an overpressure introduced by a modulator valve (more precisely at a coupling position between a fluidic conduit connected to the fluidic interface and the modulator valve) of the secondary stage sample separation device, in particular in the event of an overpressure generated as a result of a switching operation of such a modulator valve. When the overpressure at the modulator valve inlet has already been reduced by the pressure reduction mechanism to a lower pressure at the fluidic interface, i.e. before the overpressure has had an impact on the primary stage sample separation device, in particular the detector of the primary stage sample separation device is safely prevented from damage.
According to an exemplary embodiment of the invention, the pressure reduction mechanism is configured for reducing pressure at the fluidic interface in the event of an overpressure generated by a temporary at least partial incapability of the secondary stage sample separation device to receive fluidic sample material from the primary stage sample separation device (i.e. in case of a reduction or an entire loss of the fluid acceptance capability of the second stage). In other words, the pressure reduction mechanism may be activated automatically in (for instance periodic) periods in which the secondary stage sample separation device blocks fluidic sample flowing from the primary stage to the secondary stage. Such periods are considered as the origin of the overpressure pulses so that self-sufficient activation of the pressure reduction mechanism in the event of an overpressure is of particular advantage.
According to an exemplary embodiment of the invention, the pressure reduction mechanism is configured for at least temporarily (in particular as long as the overpressure remains) accommodating fluidic sample material in the event of a temporary at least partial incapability of the secondary stage sample separation device to receive fluidic sample material from the primary stage sample separation device. The pressure reduction mechanism may react on such an event for instance with the opening of a bypass channel for allowing the fluidic sample flowing from the first stage to the second stage to drain, consequently relieving or redirecting an overpressure.
According to an exemplary embodiment of the invention, the pressure reduction mechanism is configured for preventing a primary stage sample separation device from pumping fluidic sample material against a hard fluidic blockade at the secondary stage sample separation device. In the event of such a fluidic blockade, the pressure reduction mechanism may use another connected fluidic channel or a buffer volume for accommodating the fluidic sample to thereby suppress the overpressure.
According to an exemplary embodiment of the invention, the pressure reduction mechanism of the secondary stage sample separation device is arranged downstream of the fluidic interface and upstream of a modulator valve of the secondary stage sample separation device. In other words, the pressure reduction mechanism may be a fluidic member arranged as the first fluidic member in the secondary stage sample separation device.
According to an exemplary embodiment of the invention, the pressure reduction mechanism of the primary stage sample separation device is arranged downstream of the detector and upstream of the fluidic outlet of the primary stage sample separation device to which the secondary stage sample separation device is fluidically connectable. In other words, the pressure reduction mechanism may be a fluidic member arranged as the last fluidic member in the primary stage sample separation device.
According to an exemplary embodiment of the invention, the pressure reduction mechanism comprises a pressure relief valve, in particular arranged between the fluidic interface and a modulator valve of the secondary stage sample separation device. Such a pressure relief valve may be inactive as long as the pressure is below an overpressure threshold value and may open selectively in the event of an overpressure in order to then enable fluidic sample material to drain for pressure relief purposes.
According to an exemplary embodiment of the invention, the pressure relief valve is arranged and configured to disable flow of fluidic sample apart from a fluidic path between the fluidic interface and a modulator valve of the secondary stage sample separation device in the absence of overpressure (or to enable flow of fluidic sample only between the fluidic interface and a modulator valve of the secondary stage sample separation device in the absence of overpressure), and to split off flow of fluidic sample through the pressure relief valve away from said fluidic path in the event of an overpressure. For this purpose, the pressure relief valve may be arranged at or as part of a fluidic T-piece. During normal operation, i.e. in the absence of an overpressure, the flow of the fluidic sample is enabled between two connections of the T-piece and the pressure relief valve is in an inactive state. In the event of an overpressure however, a valve body of the pressure relief valve is displaced by the overpressure fluidic sample so that a third connection of the fluidic T-piece is opened to allow the excessive fluidic sample to drain via this additional channel through the pressure relief valve. Thereby, the overpressure is relieved.
According to an exemplary embodiment of the invention, the pressure relief valve is a spring biased ball valve. Thus, a spring (or any other biasing element, for instance a magnetic biasing element) biases a ball (or any other valve body such as a cone) into a position in which a fluid drain path is normally fluidically decoupled from the fluidic sample. Only when the pressure exceeds a certain threshold value (i.e. when an overpressure is present), the force of the over pressurized fluidic sample moves the ball against the spring force and thereby opens the drain path as an additional fluidic channel.
Alternatively, the pressure relief valve may be one of a spring loaded plate valve, an electrically, mechanically, hydraulically or pneumatically controlled active valve, a first tube with a radial opening closed by an elastic second tube (i.e. a so-called Dunlop valve), a counter-pressure loaded ball valve or plate valve, and an electrically driven valve.
According to an exemplary embodiment of the invention, the pressure reduction mechanism comprises an elastic member being elastically expandable in the event of an overpressure to thereby temporarily accommodate fluidic sample material for reducing pressure. An electric analogue to the elastic member is a capacitor. Such an elastic member may be a tube portion (through which the fluidic sample flows) showing sufficient elasticity and being capable of being expanded by fluid overpressure so as to temporarily accommodate additional amounts of fluidic sample. Such an elastic member may be made of an elastically deformable material such as an elastic plastic, or may be made of a metal having a sufficient elasticity. For instance, the elastic member may be configured so as to be capable of temporarily accommodating an additional fluid volume in a range between 1 μl and 3 μl. It may serve as a pressure-activated buffer volume.
According to an exemplary embodiment of the invention, the elastic member is configured as a flow-through member arranged in a fluidic conduit between the fluidic interface and a modulator valve of the secondary stage sample separation device. Thus, the elastic member may form part of the fluidic conduit fluidically connecting the fluidic interface with the modulator valve of the secondary stage sample separation device so that the pressure reduction mechanism can be provided in a compact way and with low effort.
According to another exemplary embodiment of the invention, the elastic member is arranged in a side path (for instance in a fluidic path bifurcating from the fluidic conduit) of a fluidic conduit between the fluidic interface and a modulator valve of the secondary stage sample separation device. In such an embodiment, a fluidic T-piece may be provided which has one connected conduit into which a certain portion of the fluidic sample flows during a certain operation mode of the secondary stage sample separation device. However, in the event of an overpressure caused by a blockage of the fluidic path from the primary stage sample separation device to the secondary stage sample separation device, the amount of fluidic sample flowing through the side path and filling the elastic member arranged therein can be temporarily increased. In an embodiment in which the elastic member has a blind end, the temporarily buffered fluidic sample may flow back from the elastic member towards the modulator valve of the secondary stage sample separation device after the overpressure has finished. Thus, no fluidic sample is lost. In another embodiment in which the elastic member has an end connected to a drain, the fluidic sample may at least partly flow off so that it can be prevented that historic fluid is later fed forward into the modulator valve for further separation.
According to an exemplary embodiment of the invention, the pressure reduction mechanism comprises a fluid restrictor having a higher fluidic impedance than the elastic member and being in fluid communication with a fluidic conduit between the fluidic interface and a modulator valve of the secondary stage sample separation device. An electric analogue to the fluid restrictor is an ohmic resistor. An example for such a fluid restrictor is a spatially narrowed fluidic conduit. In a normal operation mode without overpressure, substantially no or only a small amount of fluidic sample flows through the fluid restrictor (and for instance from here to a drain or a waste container). However, when the pressure increases, the amount of fluid which flows through the fluid restrictor increases as well. Thus, with a very simple passive fluidic member in form of the fluid restrictor, a failure-proof overpressure protection may be achieved and at the same time a backflow of historic liquid is avoided.
According to an exemplary embodiment of the invention, the fluid restrictor is arranged in a fluidic path which is branched off from the fluidic conduit between the fluidic interface and the modulator valve to thereby branch off fluidic sample material in the event of an overpressure. Hence, a fluidic T-piece may be implemented having a first connection towards the fluidic interface, a second connection towards a modulator valve and a third connection towards the fluid restrictor.
According to an exemplary embodiment of the invention, the fluid restrictor is connected to a waste container or a waste conduit. Thus, it can be prevented that historic fluidic sample accumulates in the narrow structures of the fluid restrictor, which results in a reliable protection against carryover.
According to an exemplary embodiment of the invention, the pressure reduction mechanism comprises at least two of the pressure relief devices having the above mentioned features, the elastic member having the above mentioned features, and the fluid restrictor having the above mentioned features. It is in particular advantageous that a highly safe pressure relief valve is combined with a reliably reversibly operating elastic member and/or fluid restrictor. The pressure relief valve is particularly effective when an overpressure remains for a long period or has a high amplitude. However, a pressure relief valve having a spring biased ball has a slight risk that, after transition from the normally inactive state into an active state, the pressure relief valve does not automatically move back into the closed state after release of the pressure. The latter reliable re-closure effect can however be very reliably achieved by a fluid restrictor or an elastic member. Thus, a synergetic combination of at least two pressure reduction mechanisms can be such that in the event of an overpressure first the fluid restrictor or elastic member is activated, and only thereafter, i.e. when the pressure reduction effect is not yet sufficient and the overpressure exceeds a further threshold value, the pressure relief valve joins the pressure reduction procedure.
According to an exemplary embodiment of the invention, the pressure reduction mechanism comprises a side branch or side path branching off or bifurcated from a fluidic conduit between the fluidic interface and a modulator valve of the secondary stage sample separation device. The side branch may comprise at least two redundant pressure reduction members of the above and/or other types. In particular and highly preferred, the pressure reduction mechanism in the side branch may comprise a fluidic serial connection of a first pressure reduction member configured as elastic member and a second pressure reduction member (or member group) downstream (in a flow direction of the fluidic sample in the side path in the event of an overpressure) of the pressure reduction member and configured as a pressure relief valve coupled to a waste via a fluidic restrictor. Such a configuration does not disturb the processing of the fluidic sample in the two-dimensional separation system in the absence of an overpressure and adds no substantial dead volume.
According to an exemplary embodiment of the invention, the secondary stage sample separation device is further configured for separating at least a portion of the supplied fluidic sample independent of a flow rate of the fluidic sample supplied from the primary stage sample separation device at the fluidic interface.
According to an exemplary embodiment of the invention, a secondary stage sample separation apparatus is provided which is mobile. This means that the secondary stage sample separation apparatus can be flexibly moved by a user to any desired primary stage sample separation device (which can be usually operated as a standalone device for sample separation when being uncoupled from the secondary stage sample separation apparatus) to which the secondary sample separation device can be connected for temporarily establishing a multidimensional sample separation system. In this multidimensional sample separation system, the primary stage performs the first sample separation and the detachably fluidically connected secondary stage performs a further separation. By configuring the secondary stage sample separation device as a spatially mobile device, it can be transported by a user to any desired primary stage sample separation device.
In an embodiment, the secondary stage sample separation device comprises a flow rate adapter configured for performing an adaptation between a value of the actual flow rate of the fluidic sample supplied by the primary stage sample separation device and a value of a flow rate, in particular a smaller flow rate value, according to which the secondary stage sample separation device is configured to operate with. According to this preferred embodiment, a provision is taken at or next or close to the fluidic interface which adapts a configurable secondary stage flow rate to a given flow rate of a presently connected primary stage sample separation device. In other words, the secondary stage sample separation device may have the flexibility to adjust its own flow rate properties so as to be able to cooperate with the flow rate conditions of a presently connected primary stage sample separation device. Such a flow rate adaptation is highly advantageous, since a completely independent operation of the secondary stage sample separation apparatus, regardless which flow rate is provided by the primary stage sample separation apparatus, could for instance result in an overflow of fluidic sample at the fluidic interface. By the provision of a flow rate adapter, the flexibly connected multiple stage sample separation system adapts itself in the secondary stage to obtain a synchronized flow rate. This may be accomplished without requiring any user action.
In an embodiment, the flow rate adapter is configured for performing the adaptation by splitting the fluid supplied to the secondary stage sample separation device into a first portion (for instance directed into a first flow path) corresponding to the flow rate used in the secondary stage sample separation device and used for further separation of the fluidic sample, and into a second portion (for instance directed into another second flow path), in particular being drained to a waste conduit or a waste container or can be sent to an additional fluidic sample detector or fraction collection device. In this embodiment, a flow rate provided by the primary stage which is too high for the secondary stage is conformed to the requirements of the secondary stage downstream of the fluidic interface by splitting the flow into a use path and into a waste path, or into two use paths in case where an additional detector is used. In the first use path with the desired flow rate of the secondary stage sample separation device, the corresponding portion of the fluidic sample can then be made subject to a further separation. The fluid in the waste path (or the second use path) can be guided to a waste container or can be stored temporarily for further processing or documentation purposes (or can be subjected to further detection).
In an embodiment, the flow rate adapter is configured for performing the adaptation by buffering consecutive portions of the fluidic sample supplied by the primary stage sample separation device into a plurality of buffer volumes, in particular sample loops, and for consecutively forwarding the buffered portions of the fluidic sample in the various buffer volumes for the further separation. In such an embodiment, a flow rate of the primary stage exceeding a desired flow rate for the secondary stage can be adjusted or adapted to one another by temporarily parking fluid packets provided by the primary stage in dedicated buffer volumes. Each of the buffer volumes may hence temporarily store a dedicated fluid packet coming from the primary stage.
For instance, these buffer volumes may be configured as sample loops provided between different fluidic ports of a fluidic valve. In the context of this application, the term “fluidic valve” may particularly denote a fluidic component which has fluidic interfaces, wherein upon switching the fluidic valve selective ones of the fluidic interfaces may be selectively coupled to one another so as to allow fluid to flow along a corresponding fluidic path, or may be decoupled from one another, thereby disabling fluid communication. By switching the fluidic valve, the individual fluid packets in the buffer volumes may then be consecutively supplied for further separation to a sample separation unit of the secondary stage sample separation device. Thus, valve switching may be controlled in such a manner that a new fluid packet from one of the buffer volumes is only introduced into the separation flow path of the secondary stage sample separation device when the latter is again ready to receive such a new fluid packet. Hence, also by the buffering or temporary parking of individual fluid packets in one or more buffer volumes, the flow rate adaptation may be performed.
In an embodiment, the flow rate adapter is configured for performing the adaptation by defining (or assigning) a flow rate to one or a plurality of buffer volumes, in a particular way, so as to buffer or park (for instance temporarily store in a respective one of the buffer volumes) a specific representative portion of the fluidic sample relating to a region of interest of a separation result (such as a separation spectrum, in particular a chromatogram in case of a chromatographic separation) for consecutively forwarding this buffered portion as the fluidic sample for the further separation.
In an embodiment, the flow rate adapter is configured for performing the adaptation by guiding the fluidic sample provided by the primary stage sample separation device into a selected one of a plurality of (for instance alternatively selectable, in particular fluidically parallel) sample separation paths in the secondary stage sample separation device, wherein each of the sample separation paths may be operable in accordance with an assigned flow rate, so as to obtain a match between the flow rate value of the primary stage sample separation device with a corresponding flow rate value assigned to the selected one of the multiple sample separation paths. In such an embodiment, multiple parallel flow paths may be provided in the secondary stage sample separation device, each configured for processing fluid with a respective flow rate. Hence, a given flow rate of the fluid originating from the primary stage sample separation device may be detected, and the corresponding best suitable one of the flow paths in terms of flow rate may be selected so as to guide the fluid coming from the primary stage into the appropriate flow path of the secondary stage.
In an embodiment, when the flow rate assigned to the presently connected primary stage sample separation device is smaller than a flow rate value processible by the secondary stage sample separation device, a flow rate measurement unit of the secondary stage sample separation device may detect this fact and may temporarily interrupt the further separation until a sufficiently large new fluid packet has arrived from the primary stage sample separation device. Then, secondary separation may be continued.
In an embodiment, the flow rate adapter comprises a modulator valve and a flow rate measurement unit for measuring a flow rate in the secondary stage sample separation device, wherein the modulator valve is controlled to switch in accordance with a measured flow rate so as to consecutively forward a predefined amount of the fluidic sample for further separation with each switch. Such a modulator valve may be a fluidic valve formed of two valve bodies which are configured to be movable relative to one another. One of these two valve bodies may have ports to be connected to fluid conduits for a fluid connection with various fluidic members of the secondary stage sample separation device. The other valve body may comprise channels such as grooves, which can fluidically connect or disconnect the respective ports in different ways in different switching states. For instance, the valve body having ports may be a stator, whereas the other valve body having the channels may be a rotor. Switching of the valve may be performed under control of a control unit such as a microprocessor. Switching may be performed under consideration of a present flow rate measured by the flow rate measuring unit. Therefore, the supply of new fluid packets to be processed (such as to be further separated) can be synchronized in accordance with the present flow rate.
In an embodiment, the fluidic interface is configured for being fluidically coupled to a waste conduit of the primary stage sample separation device. In a conventional one-dimensional sample separation device, which the primary stage sample separation device can be, the separated fluid may be guided towards a waste container via a waste conduit. In order to extend such a standalone primary stage sample separation device to a multiple stage sample separation system by connecting the secondary stage sample separation device, the latter may have a provision at its fluidic interface which allows to guide the fluid outlet towards the waste conduit to a fluidic input (at the fluidic interface) of the secondary stage sample separation device. Hence, the primary stage sample separation device is a sample separation device which needs not be specifically configured for multidimensional sample separation, but which may also operate autonomously for one-dimensional sample separation.
In an embodiment, the fluidic interface is configured as a snap-fit connector, a fitting piece of a two-part fitting (for instance a male fitting piece cooperating with a female fitting piece of the primary stage, or vice versa), a lever-based connector, a bayonet connector or a screw connector. In one embodiment, the fluidic interface has only one mechanical connection provision of one of the mentioned type or of another type. In another embodiment, multiple of such connection provisions may be provided at the fluidic interface, so that a user can select any desired of these coupling provisions for establishing a mechanical and fluidic coupling with the primary stage sample separation device. This allows to extend the flexibility of a user for using different kinds of primary stage sample separation devices together with the secondary stage sample separation device.
In an embodiment, the secondary stage sample separation device comprises a cart (such as a carriage or a vehicle) by which the secondary stage sample separation device is movable by a user. By mounting the fluidic components of the secondary stage sample separation device on a cart, which may for instance have a support for carrying the components of the secondary stage sample separation device and wheels or e.g. an air cushion for moving the cart, the secondary stage sample separation device may be flexibly transported by a user to any desired primary stage sample separation device in a laboratory or in another environment. Therefore, multidimensional sample separation is possible by having a plurality of compact primary stage sample separation devices and only one secondary stage sample separation device (or a smaller number of secondary stage sample separation devices as compared to the number of primary stage sample separation devices) being capable of serving any of these primary stage sample separation devices for temporarily establishing a multiple stage sample separation system.
In an embodiment, the secondary stage sample separation device comprises a processor (as a control unit) configured for controlling the further sample separation by the secondary stage sample separation device without controlling operation of the sample separation by the primary stage sample separation device. According to this embodiment, in fundamental contrast to conventional two-dimensional sample separation systems, the primary stage sample separation device operates autonomously by its own control unit such as a processor. Additionally, a separate processor is provided in the secondary stage sample separation device, wherein the latter processor controls operation of the secondary stage sample separation device alone and may control additionally flow adaptation at the fluidic interface between the primary stage and the secondary stage. In one embodiment, the processor of the primary stage and the processor of the secondary stage operate completely independently, i.e. without communicating with one another and/or without synchronizing their operation. In this way, it is possible that no adaptation of a conventional primary stage sample separation device is necessary to extend it by use of the secondary stage sample separation device according to an exemplary embodiment of the invention to establish a non-permanent multidimensional sample separation system.
In an embodiment, the processor is configured for synchronizing the secondary stage sample separation device with the primary stage sample separation device based on a predefined reference peak resulting from the sample separation by the primary stage sample separation device. Although the two processors can operate independently from one another, a synchronization of the operation of the primary stage and the secondary stage can be performed in terms of timing by the processor of the secondary stage sample separation device alone. In order to obtain such a synchronization, which is advantageous to derive a meaningful two-dimensional detection result, a preknown reference peak may be taken as a basis for synchronization of the timing of the secondary stage sample separation.
In an embodiment, the secondary stage sample separation device is configured for receiving data indicative of the sample separation by the primary stage sample separation device and is configured for adapting the further sample separation by the secondary stage sample separation device in accordance with the received data. In such an embodiment, the secondary stage sample separation device may be coupled to the primary stage sample separation device in such a manner that a data transfer from the primary stage to the secondary stage is enabled. For instance, the secondary stage may then receive information with regard to flow rate, a chromatographic gradient, a chromatographic method in general, etc. so that the secondary stage sample separation device may then have a deeper basis of information for adapting its own configuration to the requirements and conditions given by the primary stage. For instance, such a data transfer may be performed via a for instance wireless or wired communication interface of the secondary stage sample separation device which can be connected to a data line of the primary stage to thereby receive this data.
In an embodiment, the secondary stage sample separation device comprises an interface detector at the fluidic interface configured for redetecting (i.e. detecting again) the fluidic sample separated by the primary stage sample separation device. This redetection may occur prior to the further separation of the fluidic sample by the secondary stage sample separation device. Thus, in addition to a detector of the primary stage sample separation device which detects the separated fractions of the fluidic sample separated in the primary stage, an additional interface detector may be foreseen for instance at or close to the fluidic interface of the secondary stage sample separation device. By detecting the result of the sample separation of the primary stage, the secondary stage may receive further information with regard to the operation of the primary stage which may allow for a more refined adaptation of the operation of the secondary stage to synchronize it with the primary stage.
In an embodiment, the secondary stage sample separation device comprises a modulator valve configured for dividing the fluidic sample supplied by the primary stage sample separation device into a plurality of consecutive fluid packets and for consecutively guiding individual of the fluid packets into an analytical path of the secondary stage sample separation device in which the fluid packets of the fluidic sample are to be further separated. By such a modulator valve, the flow originating from the primary stage may be separated into subsequent packets, wherein one packet after the other may be introduced into an analytical path of the secondary stage sample separation device. In this analytical path, a sample separation unit such as a chromatographic column may be provided which performs a separation of each of the fluid packets into sub-fractions. In other words, the primary stage may separate a fluidic sample into consecutive fractions each included in one or at least one of the fluid packets, and each fluid packet with one or more fractions may then be separated, under control of the modulator valve, into a plurality of sub-sections in the secondary stage.
In an embodiment, the analytical path comprises an analytical pump for pumping mobile phase to be mixed with the fluid packets and comprises a sample separation unit for further separating the fluidic sample in the mixture. Hence, the secondary stage sample separation can be a chromatographic separation in which an analytical pump pumps a mobile phase with a high pressure upon which mixing of this mobile phase with one of the fluid packets occurs and the transport of the respective fluid packet with one or more fractions of the fluidic sample to the secondary stage sample separation unit.
In an embodiment, the modulator valve comprises a plurality of buffer volumes, in particular sample loops, each for buffering a corresponding one of the fluid packets. Thus, parking loops as buffer volumes may form part of the modulator valve.
Additionally or alternatively, the secondary stage sample separation device may comprise a plurality of buffer volumes, in particular sample loops, each for buffering a corresponding one of the fluid packets, wherein the buffer volumes are provided separately from the modulator valve and are fluidically coupled to the modulator valve. In this embodiment, the fluid packets do not form part of or are not directly connected to the modulator valve, but are arranged separately from it.
In an embodiment, the primary and/or the secondary stage sample separation device is configured as a chromatography sample separation device (in particular a liquid chromatography sample separation device, a gas chromatography sample separation device or a supercritical fluid chromatography sample separation device) or an electrophoresis sample separation device (in particular a capillary electrophoresis sample separation device). However, alternative separating technologies may be applied as well. When the secondary stage sample separation device is configured for liquid chromatography, it can be combined with a primary stage liquid chromatography device to a two-dimensional liquid chromatography apparatus (2D-LC). However, also other combinations of the sample separation techniques are possible, for instance involving electrophoresis sample separation. Advantageously, the primary stage separation and the secondary stage separation are at least partially orthogonal, i.e. separate the fluidic sample or a fraction thereof in accordance with a different separation criterion or based on a different extent of the same criterion.
In an embodiment, the sample separation system further comprises at least one further primary stage sample separation device configured for being alternatively fluidically coupleable to the secondary stage sample separation device via the fluidic interface. Therefore, multiple primary stage sample separation devices may be alternatively served by one and the same secondary stage sample separation apparatus to temporarily establish any two- or multidimensional sample separation system in a user-defined manner.
In an embodiment, the primary stage sample separation device alone is already itself a multiple stage sample separation device (for instance a two dimensional sample separation device, such as a 2D-LC). According to this embodiment, it is not only possible to form a two-dimensional sample separation system by combining a primary stage sample separation device with a secondary stage sample separation device, in contrast to this it is possible to provide a three-, four-, or five-dimensional sample separation system, or even a sample separation system with a still higher dimension.
In an embodiment, any of the primary and secondary stage sample separation devices may comprise a detector for detecting components of the separated fluidic sample. Such a detector for detecting the individual fractions and sub-fractions may be arranged downstream of the respective separating unit. Such a detector may operate on the basis of an electromagnetic radiation detection principle. For example, an electromagnetic radiation source may be provided which irradiates the sample passing through a flow cell with primary electromagnetic radiation (such as optical light or ultraviolet light). In response to this irradiation with primary electromagnetic radiation, there will be an interaction of this electromagnetic radiation with the fluidic sample so that this interaction can be detected based on variations in properties of the primary radiation (such as intensity, frequency, spectral distribution, propagation direction, vector of polarization or alike) or based on eventually emerging resulting secondary electromagnetic radiation, the said interaction being indicative of the concentration and/or kind of sample components contained in the fluidic fractions.
In an embodiment, any of the primary and secondary stage sample separation devices may comprise a sample injector for introduction of the fluidic sample into the separation system upstream of the respective separation unit. In such a sample injector of the primary stage, an injection needle may intake a metered amount of fluidic sample into a connected loop. After driving and inserting such an injection needle in a corresponding seat and upon switching a fluid injection valve, the fluidic sample may be injected into the path between a fluid drive and a separating unit. Upon such a switching operation, a mobile phase transported by the fluid drive and constituted by a solvent composition transports the sample to the separation unit and may get partially mixed with the fluidic sample. The secondary stage sample separation device may also be free of a sample injector.
In an embodiment, the primary stage separation unit and the secondary stage separation unit are configured so as to execute the respective sample separation in accordance with different separation criteria, particularly in accordance with at least partially orthogonal separation criteria. In this context, the term “orthogonal” may particularly denote the low degree or even lack of correlation between the retention parameters in the first and the second dimension in general or at least for the expected sample components.
In one embodiment, the entire fluidic sample supplied from the primary stage is further separated in the secondary stage. In another embodiment, only a part of the fluidic sample supplied from the primary stage is further separated in the secondary stage. Hence, the secondary stage may be operated in a comprehensive mode or in a heart-cut mode.
The separation unit of any of the stages may be filled with a separating material. Such a separating material which may also be denoted as a stationary phase may be any material which allows an different degree of interaction with sample components so as to be capable of separating different components of such a sample. The separating material may be a liquid chromatography column filling material or packing material comprising at least one of the group consisting of polystyrene, zeolite, polyvinylalcohol, polytetrafluorethylene, glass, polymeric powder, carbon, graphite, alumina, zirkonia, silicon dioxide, and silica gel, or any of above with chemically modified (coated, capped etc) surface. However, any packing material can be used which has material properties allowing a sample passing through this material to be separated into different components, for instance due to different degrees of interactions or affinities between the packing material and fractions of the analyte.
At least a part of any of the separation units may be fluid chambers filled with a separating material, wherein the separating material may comprise beads having a size in the range of essentially 0.1 μm to essentially 50 μm. Thus, these beads may be small particles which may be filled inside the separation section of the fluidic device. The beads may have pores having a size in the range of essentially 0.005 μm to essentially 0.2 μm. The fluidic sample may enter the pores, wherein an interaction may occur between the fluidic sample and the inner surface of the pores.
Any of the sample separation units may be a chromatographic column for separating components of the fluidic sample. Therefore, exemplary embodiments may be particularly implemented in the context of a liquid chromatography apparatus.
The sample separation system may be, in any of its stages, configured to conduct mobile phase through the system by means of a high pressure, particularly of at least 400 bar, more particularly of at least 1000 bar.
Other objects and many of the attendant advantages of embodiments of the present invention will be readily appreciated and become better understood by reference to the following more detailed description of embodiments in connection with the accompanied drawings. Features that are substantially or functionally equal or similar will be referred to by the same reference signs.
The illustration in the drawing is schematic.
Before, referring to the drawings, exemplary embodiments will be described in further detail, some basic considerations will be summarized based on which exemplary embodiments of the invention have been developed.
According to an exemplary embodiment of the invention, a two-dimensional liquid chromatography system (2D-LC) with suppression of a back pressure pulse in the first dimension is provided.
In 2D-LC, the effluate of the first dimension separation is portion-wise introduced into the second dimension by a modulation unit, typically a modulator valve (also denoted as injector valve), which directs the effluate flow into a modulation loop (also denoted as buffer volume), typically by alternatingly switching between two or more modulation loops (which may also be denoted as buffer volumes). Such flow redirection operations can be accompanied by a temporary flow path interruption. The flow rate in the first dimension is typically low and the system elasticity is high, thus it may be believed that the pressure alteration during a very short flow interruption will not be significant. This is in particular true for the pump outlet pressure on the first-dimension pump, which alters insignificantly. However, the post-column pressure alters strongly, reaching nearly the column inlet pressure within several milliseconds due to extreme system rigidity flow downstream of the column. In particular once a detector is included into the first dimension set-up (which is frequently desired or necessary), these pressure pulses can be harmful for data acquisition, causing artifacts at the base line, or even cause hardware damage to the detection cell or the column.
According to an exemplary embodiment of the invention, a pressure reduction mechanism (in particular a pressure reduction device) for suppression of the said pressure spikes in order to avoid the described negative effects is provided. In order to suppress the pressure spikes using a pressure reduction mechanism, in particular the following embodiments are possible:
In a first embodiment (see for example
In a second embodiment (see for example
In a third embodiment (see for example
In a fourth embodiment it is possible to introduce an elastic member into a side branch (an example is shown with dotted lines in
In a fifth and particularly preferred embodiment (see for example
a. an additional pressure relief valve, and/or
b. an additional restriction leading the fluid from the side branch to waste, so that no delayed material exchange back from the elastic side branch into the main flow path can take place (delayed material exchange is for instance diffusion of the content of the side branch after the pressure pulse has passed), and/or
c. a check valve on the inlet terminus of the said side elastic branch especially for preventing backflow.
According to an exemplary embodiment of the invention, a second dimension sample separation device (or secondary stage sample separation device) with an assigned separation unit is provided which is configured to fit perfectly to any existing first dimension sample separation device (or primary stage sample separation device) on-the-fly.
The optimization of (U)HPLC methods for chromatographic resolution gains importance when samples become increasingly complex (i.e. having plenty of compounds). Yet frequently one would encounter evidence (such as a shoulder or tail on a chromatographic peak) or it is a fear that there might be a hidden component that co-elutes in parallel to a substance of interest. An important application example for such a scenario can be found in the pharmaceutical industry: The “impurity profiling” workflow seeks for impurities in the active pharmaceutical ingredient (API). Impurities have to be reported down to a level of 0.05% of the API. In this case it may be a huge effort to verify. Possibilities are the re-analysis of the sample using different HPLC column media or for example to use orthogonal separation techniques, like electrophoresis. It can be very helpful if a user has a two-dimensional liquid chromatography (2D-LC) system available. Still one would have to develop and optimize a complete 2D-LC method, dedicated for this actual application or a certain application class. The result can be a dramatic loss in performance and efficiency (increased effort and longer time-to-market) due to a potential loss in analysis speed and required optimization procedures. Especial in the initial learning phase, when a user is still doing method development, a sudden unexpected result may be disturbing (at least distracting). Slightest modifications may disrupt and the effect is gone. Even if a user switches from a one-dimensional separation device to a two-dimensional separation device by using the same type of column media, a user still faces the fact that the resolution may be different and the user may have lost the track.
In order to overcome the above-mentioned shortcomings, an exemplary embodiment of the invention provides a secondary stage sample separation device that can be easily transported to aid in making the second dimension separation independent of a first (one) dimension method. For instance, an existing 1D-LC setup (as primary stage sample separation device) can be simply extended on-the-fly with a second dimension (i.e. the secondary stage sample separation device) that can be used as extension-analyzer that can automatically resolve additional features.
A secondary stage sample separation device according to an exemplary embodiment of the invention can include one of the following features:
According to an exemplary embodiment of the invention, a method of adding a second dimension separation (by providing a secondary stage sample separation device) to a running conventional system (i.e. the primary stage sample separation device) is provided, without a need to modify any hardware, software, firmware components or programmed methods of the existing system (i.e. of the primary stage sample separation device).
According to another exemplary embodiment of the invention, a second dimension subsystem (i.e. the secondary stage sample separation device) is provided, which can be attached to the outlet of an existing system (i.e. the primary stage sample separation device) to analyze the effluent in the second dimension. The subsystem can be compact, transportable, capable of being operated independently of the first dimension, whereas its operation may be synchronized (in particular as slave) to the first dimension at certain reference points. The subsystem may bear accessory means providing extended independence (for instance a flow splitter, an active flow splitter, a pump as shown in
In an embodiment, when connected to the outlet of an existing 2D-LC setup (as primary stage sample separation device), then the above described cart (as secondary stage sample separation device) actually forms the third dimension.
The sample separation system 100 is constituted by a spatially static primary stage sample separation device 10 and a movable or mobile secondary stage sample separation device 90. They are flexibly and detachably connected to one another mechanically and fluidically via a waste conduit 58 of the primary stage sample separation device 10 and via a fluidic interface 89 of the secondary stage sample separation device 90. In the shown embodiment, the fluidic interface 89 can be a snap-fit connector. For accomplishing the fluidic and mechanical coupling of the primary stage sample separation device 10 and the secondary stage sample separation device 90 according to
The secondary stage sample separation device 90 is configured for further separating fractions of the fluidic sample into sub-fractions, which fractions are provided by the primary stage sample separation device 10 as a result of the initial separation of the fluidic sample. As will be described below in further detail, the sample separation system 100 is configured for carrying out two-dimensional liquid chromatography separation (2D-LC) of a fluidic sample.
As can be taken from
Next, the operation of the primary stage sample separation device 10 will be explained. This operation can be a standalone operation, i.e. the primary stage sample separation device 10 may be operated completely independent of the optionally and flexibly connectable secondary stage sample separation device 90 when a single stage separation is sufficient. In such a standalone one-dimensional separation mode, waste conduit 58 is guided into a waste container 60 in which the separated fluidic sample is accumulated. In an extended two-dimensional separation mode as shown in
When taken alone, the primary stage sample separation device 10 operates as a one dimensional liquid separation system, as follows: A first pump 20 receives a mobile phase as a whole or as individual components that get mixed together by the first pump 20, from a first solvent supply 25, typically via a first degasser 27, which degases and thus reduces the amount of dissolved gases in the mobile phase. The first pump 20—as a mobile phase drive—drives the mobile phase through a first separating unit 30 (such as a chromatographic column) comprising a stationary phase. A first sampling unit 40 can be provided between the first pump 20 and the first separating unit 30 in order to subject or add (often referred to as sample introduction) a sample fluid (also denoted as fluidic sample) into the mobile phase. Switching of a fluidic valve 80 actually triggers the injection. The stationary phase of the first separating unit 30 is configured for separating compounds of the sample liquid. After detection of the separated fluidic sample by a first detector 50, the separated fluidic sample is further transported via waste conduit 58 and is then accumulated in the waste container 60.
A data processing unit 70, which can be a conventional PC or workstation, might be coupled (as indicated by the dotted arrows) to one or more of the devices in the primary stage sample separation device 10 in order to receive information and/or control operation. For example, the data processing unit 70 might control operation of the first pump 20 (for instance setting control parameters) and receive therefrom information regarding the actual working conditions (such as output pressure, flow rate, etc.). The data processing unit 70 might also control operation of the first solvent supply 25 (for instance setting the solvent/s or solvent mixture to be supplied) and/or the first degasser 27 (for instance setting control parameters such as vacuum level) and might receive therefrom information regarding the actual working conditions (such as solvent composition supplied over time, flow rate, vacuum level, etc.). The data processing unit 70 might further control operation of the first sampling unit 40 (for instance controlling sample injection or synchronization sample injection with operating conditions of the first pump 20). The first separating unit 30 might also be controlled by the data processing unit 70 (for instance selecting a specific flow path or column, setting operation temperature, etc.), and send—in return—information (for instance operating conditions) to the data processing unit 70. Accordingly, the first detector 50 might be controlled by the data processing unit 70 (for instance with respect to spectral or wavelength settings, setting time constants, start/stop data acquisition), and send information (for instance about the detected sample compounds) to the data processing unit 70.
In contrast to the primary stage sample separation device 10, the secondary stage sample separation device 90 is not intended to be operated as a standalone device. In contrast to this, operation of the secondary stage sample separation device 90 in terms of sample separation requires mechanical and fluidic connection between the primary stage sample separation device 10 and the secondary sample separation device 90 via the fluidic interface 89, as shown in
In the coupled state as shown in
As can be taken from
Downstream of the fluidic interface 89, the fluidic sample arriving from the primary stage sample separation device 10 (not shown in
At a fluidic T-piece 350 downstream of the interface detector 308, a part of the fluidic sample may be guided via a fluid restrictor 352 towards a waste 360, whereas another part (i.e. the rest) of the fluidic sample is guided towards a modulator valve 98. By configuring the fluid restrictor 352 to have an adjustable fluidic impedance or resistance, the individual amounts propagating towards waste 360 and towards modulator valve 98 can be adjusted in terms of flow rate adjustment between the two stages.
The modulator valve 98 is switchable under control of the control unit 97 (not shown in
However, the analytical path is, according to
Furthermore, adaptation of the flow rate between the two stages is also possible by switching the modulator valve 98 in such a manner that individual fluid packets originating from the primary stage can be buffered temporarily in one of a plurality of buffer volumes 300, configured as separate sample loops. Moreover, a flow rate measurement unit 306 may be provided for measuring a flow rate in the secondary stage sample separation device 90. The modulator valve 98 may be controlled to switch in accordance with a measured flow rate so as to consecutively forward a predefined amount of the fluidic sample for further separation with each switch. Hence, the flow rate measurement unit 306 may measure the flow rate and may supply measurement data to the processor 97 so as to control the flow rate adaptation. Thus, the fluid packets may be supplied packet-wise for further separation by firstly buffering them in one of the buffer volumes 300, and by an appropriately timed switching of the modulator valve 98 so that a new fluidic packet is only injected into one of the analytical paths when appropriate.
As can be taken from a detail 380 in
It can be furthermore taken from
As can be taken from
The flow rate adaptation pump 370 is operable so that only a desired flow rate is allowed to flow through the fluidic interface 89 of the secondary stage. In particular, a flow rate between a fluid inlet 1002 and a fluid outlet 1004 can be adjusted by the flow rate adaptation pump 370 under control of the control unit 97. The fluid with the adjustable flow rate flows via the fluid inlet 1002 through a flow rate adaptation valve 1006 and from there into a working chamber 1008 of a first piston pump 1010. A first piston 1012 reciprocates within the working chamber 1008 under control of the control unit 97. In the present scenario, the fluid flows into the working chamber 1008 with a flow rate which is defined by the motion pattern of the first piston 1012. Thus, the velocity according to which the first piston 1012 moves within the first working chamber 1008 under control of the control unit 97 defines the allowed flow rate at this moment. When the first piston 1012 has moved within the first working chamber 1008 up towards an end position in which it is not capable of receiving any further fluid, the flow rate adaptation valve 1006 is switched by the control unit 97 so that the first working chamber 1008 can be emptied towards the fluid outlet 1004 by an inverse motion of the first piston 1012. New fluid from the fluid inlet 1002 can now be accommodated in a second working chamber 1018 of a second piston pump 1020. In the period in which the fluid has been received in the first working chamber 1008, other fluid which has been previously filled into the second working chamber 1018 of the second piston pump 1020 has been guided towards the fluid outlet 1004 by a controlled motion of a second piston 1022. During the corresponding motion of the second piston 1022, the second working chamber 1018 has been emptied. This procedure can be repeated continuously. Thus, with a coordinated switching of the flow rate adaptation valve 1006 and a corresponding control of the movement of the pistons 1012, 1022, all under control of the control unit 97, the flow rate of the fluid flowing between the fluid inlet 1002 and the fluid outlet 1004 can be precisely defined.
The secondary stage sample separation device 90 is configured for separating a fluidic sample and comprises the fluidic interface 89 configured for forming a detachable fluidic coupling between the primary stage sample separation device 10 and the secondary stage sample separation device 90 so that the fluidic sample separated by the primary stage sample separation device 10 and detected by detector 50 of the first stage is fluidically supplied to the secondary stage sample separation device 90 via the fluidic interface 89 for further separation. Pressure reduction mechanism 44 is configured for reducing pressure at the fluidic interface 89 in the event of an overpressure in the secondary stage sample separation 90. The pressure reduction mechanism 44 is configured for negatively preventing the overpressure from impacting the primary stage sample separation device 10, in particular the detector 50. The pressure reduction mechanism 44 is in particular configured for reducing pressure at the fluidic interface 89 in the event of an overpressure generated by a switching operation of modulator valve 98 of the secondary stage sample separation device 90. An overpressure event is generated by a temporary incapability or reduced capability of the secondary stage sample separation device 90 to accept and further process fluidic sample material from the primary stage sample separation device 10. The pressure reduction mechanism 44 can accommodate or accept fluidic sample material selectively in the event of a temporary incapability or reduced capability of the secondary stage sample separation device 90 to receive fluidic sample material from the primary stage sample separation device 10. The pressure reduction mechanism 44 protects primary stage sample separation device 10 from pumping fluidic sample material against a temporarily fluidically blocking secondary stage sample separation device 90 and offers an alternative flow channel for excessive pressure reduction. In
In the embodiment of
Operation of the pressure reduction mechanism 44 is as follows:
When fluidic sample is supplied from the primary stage sample separation device 10 to the secondary stage sample separation device 90, consecutive fluid packets are processed by a corresponding switching sequence of the modulator valve 98. In a first operation mode, a fluid packet of the fluidic sample is delivered via a fluidic path A→B→F, while simultaneously a previously supplied fluid packet of the fluidic sample is forwarded via a fluidic path D→C→E (compare also
The difference between the embodiment of
Additionally or alternatively to the arrangement of the elastic member 1200 as just described, and as indicated with dotted lines in
The difference between the embodiment of
According to
In the event of an overpressure, the overpressure is firstly reduced by an expansion of the elastic member 1200 (and/or by compressing of the content therein). Fluidic sample flows through the expanding or inflating elastic member 1200, passes the pressure relief valve 1100 and flows into fluidic resistor 1300 towards waste 58. In the described operation mode, the pressure relief valve 1100 is still inactive. Only in an emergency scenario in which cooperation of elastic member 1200 and fluidic resistor 1300 is still incapable of reducing the overpressure to a sufficient extent, the pressure relief valve 1100 will be activated so as to direct fluidic sample through an additional flow path towards waste 58, similar as in
Moreover, the following aspects are disclosed in terms of exemplary embodiments of the invention:
It should be noted that the term “comprising” does not exclude other elements or features and the “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/IB2014/062600 | Jun 2014 | IB | international |
| 1421324.3 | Dec 2014 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2015/054763 | 6/25/2015 | WO | 00 |
