BACKGROUND ART

The present invention relates to a sample management device, a method of managing a fluidic sample, and a sample separation system.

In liquid chromatography, a fluidic sample and an eluent (liquid mobile phase) may be pumped through conduits and a separation unit such as 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. The separation unit may be connected to other fluidic members (like a sampler or an injector, a detector) by conduits. Before the fluidic sample is introduced into a separation path between a fluid drive unit (in particular a high pressure pump) and the separation unit, a predefined amount of fluidic sample shall be intaken from a sample source (such as a sample container) via an injection needle into a sample loop by a corresponding movement of a piston within a metering device. This usually occurs in the presence of a significantly smaller pressure than what the separation unit is run with. Thereafter, an injector valve is switched so as to introduce the intaken amount of fluidic sample from the sample loop of a metering path into the separation path between fluid drive unit and the separation unit for subsequent separation.

Injector valves may be configured as rotatable valves having a stator (which may have one or a plurality of fluid ports) and a rotor (which may have a plurality of grooves for connecting respective ones of the fluid ports) being rotatable with regard to the stator to thereby establish a desired fluid communication state between fluid ports and grooves. In order to be capable to withstand high pressure values of for instance up to 1200 bar in a fluid tight manner, it is necessary to press the rotor against the stator.

U.S. Pat. No. 7,575,723 discloses that, while a large primary stream of analytes flows from a chromatographic column to containers of a receiver, small samples of the analytes are diverted for flow to a mass spectrometer for analysis, by use of a transfer module. The transfer module includes a stator and a rotor or shuttle. The shuttle has an aliquot passage that initially lies in a first position where the primary stream flows through it so the aliquot passage receives a small sample. The shuttle then moves to a second position where the aliquot passage is aligned with a pump that pumps fluid out of the aliquot passage to the mass spectrometer.

U.S. Pat. No. 9,133,833 discloses methods and an apparatus for moving aliquot samples of fluid using a shuttle valve.

GB 2,345,118 discloses an injection valve which comprises a plurality of ports connected in pairs to allow fluid to flow in through a respective port and out through a second respective port and is characterised by an additional port provided in the fluid flow path of two connected ports, to provide a third port in that path. An analytical apparatus uses the valve to obtain varying concentrations of standard solution in an automated process for calibrating the apparatus.

U.S. Pat. No. 4,722,830 discloses an automated analysis system which includes a pair of sample selection subsystems whose operations are coordinated by a host computer pursuant to developing analytical data useful to a process computer in controlling an industrial process. Each subsystem includes a sample selection computer operating to control one or more multiport valves in extracting fluid samples on a scheduled or demand basis from sample loops connected with the various process streams involved with the process. The extracted samples are injected into a spectrometer for analysis. An instrument computer converts the spectrometer responses to analytical data indicative of the constituent concentrations found in an analyzed sample.

However, the functionality of conventional sample management systems is limited.

SUMMARY

It is an object of the invention to provide a flexibly operable sample management system.

According to an exemplary embodiment of the present invention, a sample management device is provided which comprises a source flow path in which a fluidic sample can flow, a volume flow adjustment unit configured for adjusting a volume flow of the fluidic sample to be branched off from the source flow path at a fluidic coupling point, and a fluidic valve fluidically coupled with the source flow path and with the volume flow adjustment unit, wherein the fluidic valve is switchable into a branch off state in which the fluidic coupling point is established within (in particular by a switching procedure of switching the fluidic valve) or is coupled into the source flow path to branch off an adjustable volume of the fluidic sample from the source flow path via the fluidic coupling point while a flow of the fluidic sample in the source flow path continues.

According to another exemplary embodiment, a method of managing a fluidic sample is provided, wherein the method comprises providing a fluidic sample flowing in a source flow path, fluidically coupling a fluidic valve with the source flow path and with a volume flow adjustment unit configured for adjusting a volume flow of the fluidic sample to be branched off from the source flow path at a fluidic coupling point, and switching the fluidic valve into a branch off state in which the fluidic coupling point is established within (or coupled into) the source flow path (in particular by the switching), and branching off a volume, being adjusted by the volume flow adjustment unit, of the fluidic sample from the source flow path via the fluidic coupling point while a flow of the fluidic sample in the source flow path continues and while the fluidic valve is in the branch off state.

According to still another exemplary embodiment, a sample separation system for separating a fluidic sample is provided, wherein the sample separation system comprises a fluid drive configured for driving a mobile phase, a separation unit configured for separating the fluidic sample in the mobile phase, and a sample management device having the above mentioned features for branching off an adjusted volume the fluidic sample for injection between the fluid drive and the separation unit.

According to an exemplary embodiment of the invention, a sample management system is provided which allows to branch off a defined amount of a fluidic sample from a source flow path without disturbing flow of the fluidic sample in this source flow path. This can be accomplished by a fluidic valve which is capable of establishing, generating or switching a fluidic coupling point (such as a fluidic T-point) into the source flow path so as to temporarily initiate a flow of a specific amount of the fluidic sample from the source flow path via the fluidic coupling point into a fluid accommodation volume in fluid communication with a volume flow adjustment unit. The volume flow adjustment unit may have the capability of precisely adjusting a volume of the fluidic sample to be branched off, for instance by controlling the pressure conditions in the fluidic path from the fluidic coupling point to the volume flow adjustment unit in relation to the pressure conditions in the source flow path. Such an adjustment may be accomplished in such a way that the conditions in the source flow path remain substantially undisturbed, so that any process in the source flow path by which the fluidic sample is processed may continue regardless of the branching off of a specific portion of the fluidic sample. This allows for simultaneously monitoring an ongoing sample processing in the source flow path. By the concept of the temporarily establishing the fluidic coupling point within the source flow path, a remaining very small influence on the source flow path may be limited not only in terms of intensity but also in terms of time. Thus, a certain amount of fluidic sample which can be precisely controlled and defined by the volume flow adjustment unit can be branched off from the substantially undisturbed source flow path. Advantageously, an only temporary switching of the fluidic coupling point for establishing a fluidic connection between the source flow path and the volume flow adjustment unit keeps the dead volume in the fluidic system very small, thereby reducing issues in terms of undesired carry-over of fluidic sample, etc.

In the following, further embodiments of the sample management device, the sample separation system, and the method will be explained.

In an embodiment, the temporarily established fluidic connection point or flow coupler is configured as a fluidic T-piece, a fluidic Y-piece, or a fluidic X-piece, In case of a fluidic T-piece and a fluidic Y-piece, two flow streams are combined at one bifurcation point into a single outlet path. In the case of a fluidic X-piece, there may be one further fluid conduit. This further fluid conduit can be a second fluid outlet conduit or a third fluid inlet conduit. Other kinds of flow couplers are possible as well.

In an embodiment, the fluidic valve is configured so that a flow of the fluidic sample in the source flow path continues substantially undisturbed in the branch off state. The term “substantially undisturbed in the branch off state” may particularly denote that a flow rate, a pressure, a fluid processing, etc. may remain substantially constant during branching off.

In particular, the fluidic valve may be configured so that a flow of the fluidic sample in the source flow path continues uninterruptedly in the branch off state. In the context of the present application, the term “flow of the fluidic sample in the source flow path continues uninterruptedly in the branch off state” may particularly denote that artifacts in a pressure curve or flow rate curve concerning the fluidic sample in the source flow path can be suppressed or even eliminated, since the flow of the fluidic sample is never reduced to zero regardless of branching off fluidic sample.

This can be accomplished by keeping the pressure conditions in a fluidic path connected to the volume flow adjustment unit on the one hand and in the source flow path on the other hand as similar as possible so as to avoid pressure peaks or switching artifacts or even an undesired pressure reduction or increase upon switching the volume flow adjustment unit into fluid communication with the source flow path. At the fluidic coupling point, which may be a fluidic T-point within the fluidic valve, a portion of the fluidic sample may continue to flow through the source flow path while another portion may be split towards the volume flow adjustment unit as a consequence of the establishing of the fluidic coupling point within the source flow path and within the fluidic valve.

In an embodiment, the fluidic coupling point is located in an interior of the fluidic valve. By integrating the fluidic coupling point in the fluidic valve, the length of the fluidic conduit from the source flow path towards the fluidic path extending from the fluidic coupling point to the volume flow adjustment unit may be kept very small. Consequently, also the dead volume may be kept very small. This reduces issues concerning carry-over of sample and keeps losses of fluidic sample small. When located in an interior of the fluidic valve, the fluidic coupling point may also be selectively switched out of fluid communication with the source flow path, thereby keeping the source flow path as uninfluenced as possible regardless of the branching off.

In an embodiment, the fluidic valve is configured so that the volume flow adjustment unit is fluidically coupled with the source flow path via the fluidic coupling point having at least three, in particular exactly three, fluid connections defined at least partially by the fluidic valve in the branch off state. When being configured with exactly three fluidic connections, the fluidic coupling point may define a fluidic T-point. However, it is also possible that the fluidic coupling point defines a fluidic Y-connection, or even a fluidic X-connection with four fluidic connections. The number of fluidic connections can be selected in accordance with the requirements of a certain application.

In an embodiment, two of the at least three fluid connections at the fluidic coupling point are fluidically coupled to or form part of the source flow path and another one of the at least three fluid connections is fluidically coupled to the volume flow adjustment unit. One of the fluid connections forming part of the source flow path may correspond to a fluidic conduit via which the fluidic sample flows towards the fluidic coupling point. The second fluid connection relating to the source flow path may correspond to a fluidic conduit through which the fluidic sample flows away from the fluidic coupling point. The fluidic coupling point relating to the fluidic valve may correspond to a fluid connection which directs the branched off fluidic sample towards a sample accommodation volume operated by the volume flow adjustment unit.

In an embodiment, the at least three fluid connections comprise two fluidic conduits of the fluidic valve fluidically coupled with one another in the branch off state (in particular one fluidic conduit of a stator and one fluidic conduit of a rotor) of the fluidic valve. For example, at least part of the fluidic conduits may be provided as grooves of a rotor and a stator of the fluidic valve. Generally, a stator of a fluidic valve may comprise one or more ports at which fluid connections to connected fluidic members may be accomplished. Furthermore, a rotor of a fluidic valve may comprise one or more fluidic conduits, such as grooves, selectively coupling or decoupling individual ones of the ports in different switching states of the fluidic valve. However, it is alternatively also possible that also the stator comprises one or more fluid conduits such as grooves to extend the functionality of the fluidic valve in terms of adjustable fluidic connections and fluidic decoupling configurations. By providing fluidic conduits such as grooves in both stator and rotor, the length of the flow paths may be kept small, which is advantageous in terms of small dead volume and other effects.

In an embodiment, the fluidic coupling point corresponds to a fluid port, in particular a fluid port of a stator, of the fluidic valve. Such a port is a spatially strictly limited fluidic coupling point keeping the dead volume small.

In an embodiment, the volume flow adjustment unit comprises an adjustment pump, in particular a metering pump. In particular, the volume flow adjustment unit may comprise a piston which can be configured for moving selectively forwardly or backwardly within a piston chamber. By such a forward or backward motion, in particular in conjunction with a corresponding pressure provided by the piston, the pressure conditions between volume flow adjustment unit and source flow path may be precisely controlled. Therefore, the configuration of the volume flow adjustment unit as such a piston driven pump is highly advantageous.

In an embodiment, the adjustment pump is configured for adjusting the volume of the fluidic sample to be branched off from the source flow path. Control of the pumping characteristics can be accomplished by controlling the time over position trajectory of the piston. For branching off, a controlled amount (such as a controlled volume or—for a temperature independent or pressure independent operation—a controlled amount of molecules) of fluidic sample can be branched off at the fluidic coupling point.

Prior to connecting the adjustment pump with the source flow path, it is possible that the pressure in a sample accommodation volume (which may be a sample loop) in fluid connection with the adjustment pump is brought to (or close to) a pressure of the source flow path (such as a reactor). After branching off fluidic sample from the source flow path into the sample accommodation volume, it is possible that the adjustment pump carries out a pressure adjustment (for instance by a piston of the adjustment pump driving in a backward direction for accomplishing a pressure release of the fluid). In a further embodiment, a negative pressure operation of a reactor can be carried out, i.e. accomplishing pressure reduction for switching the sample accommodation volume in fluid connection with the source flow path, and pressure increase (for instance ambient pressure) for fluidically decoupling the sample accommodation volume from the source flow path. However, it should be said that the description herein is independent of absolute pressure (for instance in a pressure range between 0 and 2000 bar).

In an embodiment, the volume flow adjustment unit comprises or consists of a predefined fluidic restriction. Such a predefined fluidic restriction may be a barrier for the fluidic sample flowing from the fluidic coupling point towards the fluidic restriction. Therefore, such a fluidic restriction limits the amount of fluidic sample split or branched off towards the volume flow adjustment unit. Thus, a completely passive and hence very simple configuration of the volume flow adjustment unit is possible in which the volume flow is adjusted by the value of a fluidic resistance.

In an embodiment, the volume of the fluidic sample to be branched off from the source flow path flows into a sample accommodation volume, in particular a sample loop. Such a sample accommodation volume may be a defined storage volume for the branched off fluidic sample to assume before the branched off fluidic sample is transported to a destination for further fluid processing.

In an embodiment, the sample management device comprises a destination flow path fluidically coupled with the fluidic valve being switchable into a sample supply state in which the branched off fluidic sample is supplied into the destination flow path. Thus, by a further switching of the fluidic valve into the sample supply state, the previously branched off fluidic sample can be transported to a destination flow path for further fluid processing. Advantageously, introducing the branched off amount of fluidic sample into the destination flow path may also be carried without disturbing or interrupting fluid processing in the destination flow path.

In an embodiment, the source flow path is configured for closed-loop fluid processing. Thus, the fluidic sample may be continuously processed in the source flow path, for instance driven by a pump.

In an embodiment, the source flow path comprises a fluid reactor for subjecting the fluidic sample to a reaction. When a fluid reactor is implemented in or as the source flow path, the result of the reaction of the fluidic sample in the reactor may be branched off by the volume flow adjustment unit for further processing. Thus, a reaction can be monitored quasi continuously without disturbing the reaction in the source flow path.

In an embodiment, the source flow path comprises a sample separation apparatus for separating the fluidic sample in fractions (for instance by liquid chromatography). Therefore, the fluidic sample separated into fractions in the source flow path may be branched off, for instance fraction-wise, by the volume flow adjustment unit. For instance, the volume flow adjustment unit may form part of a fractioner.

In an embodiment, the destination flow path comprises a further sample separation apparatus for further separating the fractions in sub-fractions. In this configuration, it is in particular possible that the system of source flow path, fluidic valve and destination flow path form a two-dimensional sample separation apparatus or system, in particular a two-dimensional liquid chromatography sample separation apparatus or system (2DLC). A flow from the first dimension into the second dimension may be transferred without influencing the fluid separation in the first dimension. In such an embodiment, a fluidic sample (for instance including one fraction) is taken out of the first dimension and is supplied to the second dimension. The separation in the first dimension keeps uninfluenced from the branching off, since the fluidic sample may be branched off from the source flow path only downstream of a separation unit and without flow interruption.

In an embodiment, the sample management device comprises a needle, a seat and an accommodation volume between the volume flow adjustment unit and the fluidic valve, wherein the needle is drivable selectively into the seat or out of the seat for transferring a substance between the accommodation volume and an external entity, in particular a fluid container. Thus, the portion of the sample supply device between the fluidic coupling point and the volume flow adjustment unit, including needle, seat and accommodation volume, may be configured as an injector. The needle may drive out of the seat for injecting fluidic sample which has been previously branched off from a source flow path into a separate apparatus, for instance a separate liquid chromatography apparatus. But it is also possible that the needle drives into a fluid container such as a vial before intaking a medium.

In an embodiment, the sample management device comprises a sample separation apparatus into which the branched off fluidic sample is injectable from the external entity. Such an embodiment is shown inFIG. 7toFIG. 11.

In an embodiment, the sample separation apparatus comprises a further needle, a further seat and a further accommodation volume, wherein the further needle is drivable selectively into the further seat or out of the further seat for transferring the branched off fluidic sample from the external entity into the further accommodation volume. It is alternatively also possible that a common needle is used for the injector portion of the sample management device and the further injector portion of the sample management device. By taking this measure, a vial for temporarily storing the branched off fluidic sample may be dispensable.

In an embodiment, the fluidic valve is switchable in a pressure adjustment state in which the source flow path is fluidically decoupled from the volume flow adjustment unit and in which the volume flow adjustment unit is operable for adjusting a pressure between the volume flow adjustment unit and the fluidic valve. In particular, the volume flow adjustment unit may be operable for adjusting the pressure in the pressure adjustment state to reduce a pressure difference to another pressure in the source flow path prior to switching the fluidic valve in the branch off state. Thus, pre-compression or decompression is possible while the sample management device is in the pressure adjustment state. Thereby, differing pressures in the source flow path and the fluidic path connected to the volume flow adjustment unit can be adjusted to one another prior to coupling them in the branch off state, thereby preventing pressure shocks and other artifacts.

In an embodiment, the fluidic valve comprises a stator and a rotor being rotatable relative to one another, wherein the stator comprises a plurality of ports and optionally one or more fluid conduits, and the rotor comprises at least one fluid conduit (in particular a plurality of fluid conduits, such as one or more grooves). The conduit(s) may be selectively fluidically coupled with or decoupled from the stator ports by rotating the rotor relative to the stator.

In an embodiment, the fluidic valve has at least the following ports (which may be established as part of a stator of a rotatable fluidic valve):a source flow-in port through which the fluidic sample can be guided to flow from the source flow path into the fluidic valve;a source flow-out port (which may be equal to the fluidic coupling point, for instance in the branch off state) through which branched off fluidic sample can flow away from the source flow path and not-branched off fluidic sample can remain flowing within the source flow path; anda branch off port (which may be a central port of the fluidic valve) through which the branched off fluidic sample can flow to a sample accommodation volume in fluid communication with the volume flow adjustment unit.

By such a valve configuration, branching off a portion of the fluidic sample may be accomplished with very low impact on the source flow path and with small dead volume.

Correspondingly, the fluidic valve may have an “in” and an “out” connection for the source flow path as well as a channel end point, which may be fluidically coupled to the volume flow adjustment unit, for providing or establishing the fluidic coupling point (in particular in a dedicated switching state of the fluidic valve such as the branch off state).

In an embodiment, the fluidic valve is switchable into at least one other state (i.e. in a switching state which differs from the branch off state) in which no fluidic coupling point (of the above described type) fluidically coupling the volume flow adjustment unit and the source flow path is established within the source flow path. Thus, the fluidic coupling point may be a temporary fluidic coupling point (such as a temporary fluidic T-junction) which is established only in a specific switching state of the fluidic valve, but is absent in another switching state of the fluidic valve.

In an embodiment, the fluidic coupling point is defined by a fluidic coupling position between the source flow path and a channel end point (see reference numeral145inFIG. 3) of a volume flow adjustment path including the volume flow adjustment unit. The channel end point may be constituted as the dead end of a rotor groove of the fluidic valve fluidically coupled with the volume flow adjustment unit. This enables a temporary formation of a fluidic T-point or the like for sample branch off with small or even zero dead volume (so that undesired sample carryover as well as non-flushed channels can be prevented).

In an embodiment, the fluidic valve is switchable into at least one other state (i.e. another state than the branch off state) in which the volume flow adjustment unit and the source flow path are decoupled from one another. Thus, it is possible that the fluidic connection between source flow path and a sample accommodation volume operated by the volume flow adjustment unit is only provided temporarily in a certain valve position (i.e. in the branch off state, compare for instanceFIG. 2), whereas in one or more other valve positions (such as in the sample supply state, compare for instanceFIG. 4), such a fluidic T-piece (or the like) establishing a fluidic coupling of source flow path and sample accommodation volume via the fluidic coupling point is removed or inactive. In one embodiment, the fluidic valve may be switchable into at least one state in which the fluidic coupling point is decoupled from source flow path and/or volume flow adjustment unit or is absent at all.

Embodiments of the above described sample management device may be implemented in or functionally connected to conventionally available HPLC systems, such as the Agilent 1200 Series Rapid Resolution LC system or the Agilent 1100 HPLC series (both provided by the applicant Agilent Technologies—see the website agilent.com—which shall be incorporated herein by reference).

One embodiment of a sample separation apparatus or system, in which a sample management device of the above described type may be implemented, comprises a pumping apparatus as fluid drive or mobile phase drive having a pump piston for reciprocation in a pump working chamber to compress liquid in the pump working chamber to a high pressure at which compressibility of the liquid becomes noticeable.

The separation unit of the sample separation system preferably comprises a chromatographic column (see for instance the website en.wikipedia.org/wiki/Column_chromatography) providing the stationary phase. The column may be a glass or steel tube (for instance with a diameter from 50 μm to 5 mm and a length of 1 cm to 1 m) or a microfluidic column (as disclosed for instance in EP 1577012 or the Agilent 1200 Series HPLC-Chip/MS System provided by the applicant Agilent Technologies). The individual components are retained by the stationary phase differently and at least partly separate from each other while they are propagating at different speeds through the column with the eluent. At the end of the column they elute one at a time or at least not entirely simultaneously. During the entire chromatography process the eluent may be also collected in a series of fractions. The stationary phase or adsorbent in column chromatography usually is a solid material. The most common stationary phase for column chromatography is silica gel, surface modified silica gel, followed by alumina. Cellulose powder has often been used in the past. Also possible are ion exchange chromatography, reversed-phase chromatography (RP), affinity chromatography or expanded bed adsorption (EBA). The stationary phases are usually finely ground powders or gels and/or are microporous for an increased surface.

The mobile phase (or eluent) can be a pure solvent or a mixture of different solvents (such as water and an organic solvent such as ACN, acetonitrile). It can be chosen for instance to minimize the retention of the compounds of interest and/or the amount of mobile phase to run the chromatography. The mobile phase can also be chosen so that the different compounds or fractions of the fluidic sample can be separated effectively. The mobile phase may comprise an organic solvent like for instance methanol or acetonitrile, often diluted with water. For gradient operation water and organic solvent are delivered in separate bottles, from which the gradient pump delivers a programmed blend to the system. Other commonly used solvents may be isopropanol, tetrahydrofuran (THF), hexane, ethanol and/or any combination thereof or any combination of these with aforementioned solvents.

The fluidic sample may comprise but is not limited to any type of process liquid, natural sample like juice, body fluids like plasma or it may be the result of a reaction like from a fermentation broth.

The pressure, as generated by the fluid drive, in the mobile phase may range from 2-200 MPa (20 to 2000 bar), in particular 10-150 MPa (100 to 1500 bar), and more particularly 50-120 MPa (500 to 1200 bar).

The sample separation apparatus or system, for instance an HPLC system, may further comprise a detector for detecting separated compounds of the fluidic sample, a fractionating unit for outputting separated compounds of the fluidic sample, or any combination thereof. Further details of such an HPLC system are disclosed with respect to the Agilent 1200 Series Rapid Resolution LC system or the Agilent 1100 HPLC series, both provided by the applicant Agilent Technologies, under the website agilent.com which shall be incorporated herein by reference.

Embodiments of the invention can be partly or entirely embodied or supported by one or more suitable software programs, which can be stored on or otherwise provided by any kind of data carrier, and which might be executed in or by any suitable data processing unit. Software programs or routines can be preferably applied in or by the control unit.

