Injector Serving Multiple Sample Separation Apparatuses

Abstract

An injector, for injecting a fluidic sample in at least one selected one of a first sample separation apparatus and a second sample separation apparatus, includes a valve arrangement fluidically connectable to the first sample separation apparatus and the second sample separation apparatus, a sample accommodation volume for accommodating the fluidic sample, and a control unit configured for controlling the valve arrangement so that fluidic sample in the sample accommodation volume is selectively injectable into the selected first sample separation apparatus and/or second sample separation apparatus.

Claims

1. An injector for injecting a fluidic sample in at least one selected one of a first sample separation apparatus and a second sample separation apparatus, wherein the first sample separation apparatus and the second sample separation apparatus comprise separate independent flow paths, the first sample separation apparatus comprising a first fluid drive unit configured for driving a first mobile phase and/or the fluidic sample and a first sample separation unit configured for separating the fluidic sample, and the second sample separation apparatus comprising a second fluid drive unit configured for driving a mobile phase and/or the fluidic sample and a second sample separation unit configured for separating the fluidic sample, the injector comprising: a valve arrangement being fluidically connectable to the first sample separation apparatus and to the second sample separation apparatus; a sample accommodation volume for accommodating the fluidic sample; and a control unit configured for controlling to control the valve arrangement so that fluidic sample in the sample accommodation volume is selectively injectable into at least one of the first sample separation apparatus or the second sample separation apparatus.

2. The injector according to claim 1, wherein the valve arrangement comprises only a single fluid valve.

3. The injector according to claim 1, wherein the sample accommodation volume is fluidically connected with the valve arrangement or forms part of the valve arrangement.

4. The injector according to claim 1, wherein the valve arrangement comprises a stator and a rotor being movable relative to the stator, wherein the stator comprises a plurality of ports to be connected at least to the first sample separation apparatus, the second sample separation apparatus and the sample accommodation volume, and the rotor comprises one or more conduits, wherein different fluidic coupling and/or decoupling states between the ports and the one or more conduits are establishable by switching the valve arrangement.

5. The injector according to claim 1, wherein the injector is configured for injecting the fluidic sample from the sample accommodation volume into at least one selected one of the first sample separation apparatus and the second sample separation apparatus by combining, at a fluidic connection point, a sample flow from a first inlet flow path supplying the fluidic sample from the sample accommodation volume with a mobile phase flow from a second inlet flow path supplying mobile phase of at least one of the first sample separation apparatus and the second sample separation apparatus, so that the mobile phase and the fluidic sample are combined at the fluidic connection point to flow into an outlet flow path towards at least one the first sample separation apparatus or the second sample separation apparatus.

6. The injector according to claim 1, wherein the sample accommodation volume is provided as a single common sample accommodation volume for accommodating fluidic sample to be injected selectively into at least one selected one of the first sample separation apparatus and the second sample separation apparatus.

7. The injector according to claim 1, comprising a metering unit configured for driving the fluidic sample to flow into the sample accommodation volume.

8. The injector according to claim 1, comprising a needle and a seat, wherein the needle is configured to be movable out of the seat and into a sample container for transferring fluidic sample from the sample container into the sample accommodation volume, and wherein the needle is drivable back into the seat for injecting the transferred fluidic sample from the sample accommodation volume into at least one of the first sample separation apparatus or the second sample separation apparatus.

9. The injector according to claim 8, wherein the needle and the seat are provided as a single common needle-seat arrangement for transferring fluidic sample into at least one selected one of the first sample separation apparatus and the second sample separation apparatus.

10. The injector according to claim 1, configured for pre-compressing the fluidic sample in the sample accommodation volume before injecting the pre-compressed fluidic sample into at least one selected one of the first sample separation apparatus and the second sample separation apparatus.

11. The injector according to claim 10, configured for pre-compressing the fluidic sample in the sample accommodation volume up to a pre-compression pressure value which is below a system pressure value of at least one of the first sample separation apparatus or the second sample separation apparatus.

12. The injector according to claim 1, configured for decompressing the sample accommodation volume after injecting fluidic sample from the sample accommodation volume into at least one selected one of the first sample separation apparatus and the second sample separation apparatus and before accommodating further fluidic sample in the sample accommodation volume.

13. The injector according to claim 1, comprising a flushing unit configured to flush at least one selected from the group consisting of: the sample accommodation volume; a needle; a seat; at least a part of ports of the injector; at least a part of conduits of the injector; and at least a part of conduits of at least one of the first sample separation apparatus or the second sample separation apparatus.

14. The injector according to claim 1, wherein the control unit is configured to control the valve arrangement so that a fluidic sample separation procedure runs in one of the first sample separation apparatus or the second sample separation apparatus, while the other of the first sample separation apparatus and the second sample separation apparatus performs another task.

15. A sample separation system for separating a fluidic sample, the sample separation system comprising: a first sample separation apparatus for separating the fluidic sample; a second sample separation apparatus for separating the fluidic sample; and an injector comprising: a valve arrangement fluidically coupled with the first sample separation apparatus and the second sample separation apparatus; a sample accommodation volume for accommodating the fluidic sample; and a control unit configured to control the valve arrangement so that fluidic sample in the sample accommodation volume is selectively injectable into at least one of the first sample separation apparatus or the second sample separation apparatus.

16. The sample separation system according to claim 15, wherein the first sample separation apparatus and the second sample separation apparatus are configured for separating the fluidic sample using different separation methods and/or different detection methods.

17. The sample separation system according to claim 15, wherein the first sample separation apparatus and the second sample separation apparatus are configured for separating the fluidic sample using the same separation methods and/or the same detection methods.

18. The sample separation system according to claim 15, further comprising at least one of the following features: wherein the first sample separation apparatus and the second sample separation apparatus are selected from a group consisting of: a chromatography apparatus; a liquid chromatography apparatus; a gas chromatography apparatus; a supercritical fluid chromatography apparatus; a reversed-phase liquid chromatography apparatus; a normal phase liquid chromatography apparatus; a multi-dimensional chromatography apparatus; a HILIC apparatus; an HPLC apparatus; a mass spectrometer apparatus; a gel electrophoresis apparatus; and a solid phase extraction separation apparatus; comprising at least one third sample separation apparatus for separating the fluidic sample, wherein the injector is configured for selectively injecting the fluidic sample in at least one selected one of the at least one third sample separation apparatus; wherein at least one of the the first sample separation apparatus or the second sample separation apparatus comprises a detector configured to detect separated fractions of the fluidic sample; wherein at least one of the first sample separation apparatus and the second sample separation apparatus comprises a fractioner unit configured to collect separated fractions of the fluidic sample; wherein at least one of the first sample separation apparatus and the second sample separation apparatus comprises a degassing apparatus for degassing mobile phase before injecting the fluidic sample in the mobile phase.

19. A method of injecting a fluidic sample selectively into at least one of a first sample separation apparatus and a second sample separation apparatus, the method comprising: accommodating the fluidic sample in a sample accommodation volume; and switching a valve arrangement being fluidically connected to the first sample separation apparatus and to the second sample separation apparatus so that the fluidic sample in the sample accommodation volume is selectively injected into at least one selected one of the first sample separation apparatus and the second sample separation apparatus depending on a switching state of the valve arrangement.

20. The method according to claim 19, comprising at least one of the following features: injecting the fluidic sample from the sample accommodation volume into at least one selected one of the first sample separation apparatus and the second sample separation apparatus by combining, at a fluidic connection point, a sample flow from a first inlet flow path supplying the fluidic sample from the sample accommodation volume with a mobile phase flow from a second inlet flow path supplying mobile phase of at least one of the first sample separation apparatus or the second sample separation apparatus, so that the mobile phase and the fluidic sample are combined at the fluidic connection point to flow into an outlet flow path towards at least one of the first sample separation apparatus or the second sample separation apparatus; pre-compressing the fluidic sample in the sample accommodation volume before injecting the pre-compressed fluidic sample into at least one selected one of the first sample separation apparatus and the second sample separation apparatus; decompressing the sample accommodation volume after injecting fluidic sample from the sample accommodation volume into at least one selected one of the first sample separation apparatus and the second sample separation apparatus and before accommodating further fluidic sample in the sample accommodation volume; flushing at least one selected from the group consisting of: the sample accommodation volume; a needle; a seat; at least a part of ports; and at least part of conduits; running a fluidic sample separation procedure in one of the first sample separation apparatus or the second sample separation apparatus, while the other of the first sample separation apparatus and the second sample separation apparatus performs another task.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0044] 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.

[0045] FIG. 1 shows a sample separation system comprising two liquid sample separation apparatuses in accordance with embodiments of the present invention, particularly used in high performance liquid chromatography (HPLC).

[0046] FIG. 2 to FIG. 6 illustrate different operation states of an injector operating two sample separation apparatuses of a sample separation system according to an exemplary embodiment of the invention.

[0047] FIG. 7 and FIG. 8 illustrate injectors operating two sample separation apparatuses of a sample separation system according to other exemplary embodiments of the invention.

[0048] The illustration in the drawing is schematically.

[0049] Before describing the figures in further detail, some basic considerations of the present invention will be summarized based on which exemplary embodiments have been developed.

[0050] According to an exemplary embodiment of the invention, a dual stream feed injector is provided capable of serving multiple sample separation apparatuses sequentially or simultaneously. In particular, such an injector may integrate two or more samplers in one housing (in particular sharing trays, needle, loop, etc.). A corresponding sample separation system may include two or more independent flow paths, both suitable for separation of a fluidic sample and preferably combined in one valve arrangement, even more preferably in a single fluid valve. A corresponding embodiment has the advantage of having substantially no dead volume in view of the shared use of various fluidic members in the sample separation system.

[0051] In an embodiment, various components of the sample separation system, in particular one or more of a metering unit for metering and driving fluidic sample, a loop, a needle and a seat may be purgeable by a flushing unit (which may for instance be embodied by a flush pump being operated with for example three solvents).

[0052] It is also possible that a pre-compression forms part of the functionality of the injector allowing a fluidic sample in a sample accommodation volume to be pre-compressed prior to being combined with a mobile phase flowing between a fluid drive unit and a sample separation unit of the respective one of the sample separation apparatuses. Pre-compression may reduce or eliminate pressure shocks occurring during switching a fluid valve and may therefore increase the lifetime of the fluidic members of the sample separation system.

[0053] The usage of a corresponding setup may provide a hydraulic junction with the capability to compress and/or decompress an arrangement of loop, needle and/or seat with a corresponding operation of a metering unit before and/or after switching into or out of a flow path between a fluid drive unit and a sample separation unit of a respective one of the sample separation apparatuses. Furthermore, such a metering unit may be self-purgeable with fresh solvent which can be provided by a solvent selection valve or a solvent container.

[0054] A corresponding injector architecture may be retrofitted on existing samplers. A metering unit may be rendered purgeable. The mobile phase of each sample separation apparatus can work independently. Therefore, the solvents used in both flow or separation paths can be different, if desired or required. Furthermore, the type of analysis can be different so that, descriptively speaking, a multi-method sample separation system may be provided. For example, it is possible to do HILIC (Hydrophilic Interaction Chromatography) and RP (reversed-phase) applications out of one vial in the injector or sampler without disturbing each other. By using one common injector for operating multiple sample separation apparatuses, bench space may be saved, because a corresponding sample separation system may be embodied with only one stack of modules of fluidic members instead of two.

[0055] Exemplary embodiments of the invention may involve one or more of the advantages mentioned in the following:

[0056] In order to exclude needle, seat, loop and metering unit from a main path of a first or second separation unit, the setup described herein can be used. Fluidic sample may be taken by plunger movement of a metering unit. The sample draw speed may be adjustable and can be set as method parameter. Only marginal pressure fluctuations (depending on injection/draw mode) may occur, due to sample path pre-compression. Furthermore, a low carryover can be obtained due to a purge position in which also the needle can be lifted to clean the needle-seat interface (with solvent pumped from the metering unit). Beyond this, a draw volume of aspirated fluidic sample may be selectable. There are substantially no limitations concerning such a volume which may thus be selectable in a range of maximum volume of the loop installed. An injector according to an exemplary embodiment of the invention may be operated with a stable pressure of for instance up to 1300 bar or more.

[0057] Referring now in greater detail to the drawings, FIG. 1 depicts a general schematic of a sample separation system 140 configured as configured as liquid separation system according to an exemplary embodiment of the invention. A pump as fluid drive unit 20 receives a mobile phase from a solvent supply 25, typically via a degasser 27, which degases and thus reduces the amount of dissolved gases in the mobile phase. The mobile phase drive or fluid drive unit 20 drives the mobile phase through a selectable one of two separation units 30 (such as chromatographic columns) comprising a stationary phase. A single sampler or injector 40, implementing a valve arrangement 106 with a single fluid valve 110, can be provided between the fluid drive unit 20 and the separation units 30 in order to subject or add (often referred to as sample introduction) a sample fluid into the mobile phase and supply the mixture of mobile phase and fluidic sample to a respective one of the separation units 30, depending on a switching state of fluid valve 110. The stationary phase of the separation units 30 is configured for separating compounds of the sample liquid. A respective one of two detectors 50 is provided for detecting separated compounds of the sample fluid. A respective fractionating unit 60 can be provided for outputting separated compounds of sample fluid. As shown, each of two sample separation apparatuses 102, 104 comprises a respectively separate separation unit 30, detector 50, and fractionating unit 60.

[0058] While the mobile phase can be comprised of one solvent only, it may also be mixed from plural solvents. Such mixing might be a low pressure mixing and provided upstream of the fluid drive unit 20, so that the fluid drive unit 20 already receives and pumps the mixed solvents as the mobile phase. Alternatively, the fluid drive unit 20 might be comprised of plural individual pumping units, with plural of the pumping units each receiving and pumping a different solvent or mixture, so that the mixing of the mobile phase (as received by a respective one of the separation units 30) occurs at high pressure and downstream of the fluid drive unit 20 (or as part thereof). The composition (mixture) of the mobile phase may be kept constant over time, the so called isocratic mode, or varied over time, the so called gradient mode.

[0059] A data processing unit or control unit 70, which can be a PC or workstation, may be coupled (as indicated by the dotted arrows) to one or more of the devices in the sample separation system 140 in order to receive information and/or control operation. For example, the control unit 70 may control operation of the fluid drive unit 20 (for example setting control parameters) and receive therefrom information regarding the actual working conditions (such as output pressure, etc. at an outlet of the pump). The control unit 70 may also control operation of the solvent supply 25 (for example setting the solvent/s or solvent mixture to be supplied) and/or the degasser 27 (for example setting control parameters such as vacuum level) and might receive therefrom information regarding the actual working conditions (such as solvent composition supplied over time, vacuum level, etc.). The control unit 70 might further control operation of the sampling unit or injector 40 (for example controlling sample injection or synchronization sample injection with operating conditions of the fluid drive unit 20). The separation units 30 might also be controlled by the control unit 70 (for example selecting a specific flow path or column, setting operation temperature, etc.), and send—in return—information (for example operating conditions) to the control unit 70. Accordingly, the detectors 50 may be controlled by the control unit 70 (for example with respect to spectral or wavelength settings, setting time constants, start/stop data acquisition), and send information (for example about the detected sample compounds) to the control unit 70. The control unit 70 might also control operation of the fractionating units 60 (for example in conjunction with data received from the detectors 50) and provides data back.

[0060] The solvent supply 25 is configured for metering liquids in controlled proportions and for supplying a resultant mixture. The solvent supply 25 comprises two reservoirs 101, 103, with each of the reservoirs 101, 103 containing a respective solvent A (in this example water), B (in this example a buffer, i.e. salt dissolved in a solvent). Moreover, it is possible to provide one or more additional reservoirs, for instance an additional reservoir comprising an organic solvent, a further reservoir comprising an optional organic modifier, etc. Each of the reservoirs 101, 103 is fluidically connected via a respective liquid supply line 119 with a proportioning unit 105 which may be configured as proportioning valve. The proportioning unit 105 is configured to connect a selected one of the liquid supply lines 119 with a supply line 109, and to switch between different liquid supply lines 119. The supply line 109 is connected with an inlet of the fluid drive unit 20. Hence, solvent blending is performed at the low-pressure side of the fluid drive unit 20 by metering or proportioning a sequence of fluidic portions.

[0061] The fluidic members described above form sample separation system 140 for separating a liquid sample according to an exemplary embodiment of the invention. The sample separation system 140 comprises the first sample separation apparatus 102 for separating the fluidic sample making use of the previously described fluid drive unit 20, one of the sample separation units 30 and one of the detectors 50. The second sample separation apparatus 104 of the sample separation system 140 also serves for separating liquid sample and makes use of the same (as shown) or a separate second fluid drive unit 20, another one of the sample separation units 30 and another one of the detectors 50. The injector 40 shown in FIG. 1 can be operated, controlled by the control unit 70, for selectively injecting the fluidic sample in the first sample separation apparatus 102 or in the second sample separation apparatus 104, depending on a switching state of fluid valve 110.

[0062] Thus, the injector 40 is configured for injecting a fluidic sample in first sample separation apparatus 102 or in second sample separation apparatus 104 depending on a switching state of fluid valve 110. The injector 40 comprises valve arrangement 106 with fluid valve 110 being fluidically connected to the first sample separation apparatus 102 and to the second sample separation apparatus 104. A sample accommodation volume 108, which may for instance be configured as a sample loop, may serve for temporarily accommodating the fluidic sample before it is supplied to one of the first sample separation apparatus 102 and the second sample separation apparatus 104. The control unit 70 is programmed for controlling the valve arrangement 106, i.e. for controlling switching of the fluid valve 110, so that the fluidic sample in the sample accommodation volume 108 is selectively injected from sample accommodation volume 108 either in the first sample separation apparatus 102 or in the second sample separation apparatus 104 for subsequent separation. In an embodiment, it may also be possible to split fluidic sample in the sample accommodation volume 108 so as to be partially separated by the first sample separation apparatus 102, while another part of the fluidic sample will be separated by the second sample separation apparatus 104. Injector 40 serves for injecting fluidic sample in a selectable one of the first sample separation apparatus 102 and the second sample separation apparatus 104.

[0063] In the embodiment according to FIG. 1, the injector 40 may hence be switched to either inject the fluidic sample from the sample accommodation volume 108 into the first sample separation apparatus 102 or into the second sample separation apparatus 104. The first sample separation apparatus 102 with separation unit 30, detector 50 and fractioner 60 has been described above and is driven by fluid drive unit 20. In a corresponding way, the second sample separation apparatus 104 is operated by the same fluid drive unit 20, but has a separate separation unit 30, detector 50 and fractioner 60. By correspondingly switching the injector 40, the fluidic sample may be supplied from the sample accommodation volume 108 either in only the first sample separation apparatus 102, or in only the second sample separation apparatus 104, or in both sample separation apparatuses 102, 104. The corresponding operation mode of the injector 40 may be adjusted for example automatically under control of the control unit 70, or may be input by a user via a corresponding user input.

[0064] FIG. 2 to FIG. 6 illustrate different operation states of an injector 40 operating two sample separation devices 102, 104 according to an exemplary embodiment of the invention. Referring to FIG. 2 to FIG. 6, a sample separation system 140 with a dual stream feed injector 40 according to an exemplary embodiment of the invention is shown.

[0065] The first sample separation apparatus 102 and the second sample separation apparatus 104 of the sample separation system 140 are each configured for separating fluidic sample accommodated in a sample accommodation volume 108, which is here embodied as a sample loop, i.e. as a looped fluidic conduit. Operation of the first sample separation apparatus 102 and of the second sample separation apparatus 104 may be carried out using different or the same separation methods (for instance a chromatographic sample separation in a gradient mode, and another chromatographic sample separation in an isocratic mode) and/or different detection methods (for instance using a fluorescence detector and a mass spectrometer). It is however also possible that the sample separation apparatuses 102, 104 carry out the same separation method and/or use the same detection method. In the shown embodiment, both the first sample separation apparatus 102 and the second sample separation apparatus 104 may be liquid chromatography apparatuses. As shown in FIG. 2 to FIG. 6, the first sample separation apparatus 102 and the second sample separation apparatus 104 comprise separate independent flow paths, enabling the use of different mobile phases, if desired or required, for the sample separation apparatuses 102, 104.

[0066] As shown in a detail 121 in FIG. 2 illustrating a cross-section of fluid valve 110 of valve arrangement 106 of the injector 40, the fluid valve 110 is composed of a stator 112, which remains stationary during operation, and a rotor 114, which may be rotated relative to the stator 112 during operation. The stator 112 comprises a plurality of ports 116 to be connected to conduits 141 of the first sample separation apparatus 102, to conduits 143 of the second sample separation apparatus 104, to the sample accommodation volume 108, to a metering unit 122, to a seat 126 cooperating with a needle 124, to a flushing unit 130, and to a waste line. The rotor 114 comprises multiple fluidic conduits 118 which are here embodied in form of arcuate and radial grooves in the rotor 114. Different fluidic coupling states and/or decoupling states are establishable between the mentioned fluidic members connected to the ports 116 by switching the valve arrangement 106 so that, in each switching state, the fluidic conduits 118 may couple respective ports 116, or not (compare FIG. 2 to FIG. 6).

[0067] As can be taken from FIG. 2, some of the conduits 118 are shaped as arcuate grooves formed in the rotor 114, wherein another one of the conduits 118 is arranged as a radially extending groove in the rotor 114. The before mentioned arcuate and radial grooves may be located in the same or different planes perpendicular to the paper plane of FIG. 2 to FIG. 6, but may be switched simultaneously. In contrast to this, two shorter arcuate grooves are formed also in the stator 112 and therefore remain at the same angular position in each of FIG. 2 to FIG. 6. For the sake of simplicity, the conduits 118 and the ports 116 are only shown in FIG. 2.

[0068] The illustrated injector 40 is configured for injecting pre-loaded or aspirated fluidic sample from the sample accommodation volume 108 into a flow path (see conduits 141) between a respective fluid drive unit 20 and sample separation unit 30 of the first sample separation apparatus 102 in one switching state of the fluid valve 110. In another switching state of the fluid valve 110, the shown injector 40 is configured for injecting pre-loaded fluidic sample from the sample accommodation volume 108 into a flow path (see conduits 143) between another fluid drive unit 20 and another sample separation unit 30 of the second sample separation apparatus 104.

[0069] Moreover, the injector 40 is configured for combining, at a respective fluidic connection point 120, 120′, a flow path of the fluidic sample with another flow path of mobile phase flowing in a respective one of the first sample separation apparatus 102 and the second sample separation apparatus 104 between a respective fluid drive unit 20 and sample separation unit 30.

[0070] Referring to FIG. 2, a sample flow from a first inlet flow path 153 supplying the fluidic sample may be connected with another mobile phase flow from a second inlet flow path 151 supplying mobile phase of first sample separation apparatus 102 at the fluidic connection point 120. Consequently, the mobile phase and the fluidic sample may be combined at the fluidic connection point 120 to flow into an outlet flow path 155 towards the first sample separation apparatus 102.

[0071] Referring to FIG. 5, a sample flow from a first inlet flow path 163 supplying the fluidic sample may be connected with another mobile phase flow from a second inlet flow path 161 supplying mobile phase of second sample separation apparatus 104 at the fluidic connection point 120′. Consequently, the mobile phase and the fluidic sample may be combined at the fluidic connection point 120′ to flow into an outlet flow path 165 towards the second sample separation apparatus 104.

[0072] As shown, only one single common sample accommodation volume 108 is provided for accommodating fluidic sample to be injected selectively into the first sample separation apparatus 102 or the second sample separation apparatus 104. Since the injector 40 serves two sample separation apparatuses 102, 104 simultaneously, the injector 40 and consequently the sample separation system 140 may be formed in a compact way. Correspondingly, only one single common metering unit 122 is provided and configured for driving the fluidic sample to flow from a sample container 128 into the sample accommodation volume 108, and later from the sample accommodation volume 108 in one of the first and second sample separation apparatuses 102, 104. For this purpose, the sample accommodation volume 108 and the metering unit 122 cooperate with needle 124 and seat 126 of a cooperating needle-seat arrangement. The needle 124 may be moved out of the seat 126 (not shown) and into sample container 128 containing fluidic sample. When the needle 124 is immersed in the fluidic sample in the sample container 128, fluidic sample may be transferred from the sample container 128, via the needle 124 into the sample accommodation volume 108 by withdrawing a piston of the metering unit 122. After such a sample intake, the needle 124 may be driven back into the seat 126 to form a fluid tight coupling with the seat 126 (as shown in FIG. 2 to FIG. 6). Thereafter, the transferred fluidic sample may be injected from the sample accommodation volume 108 into the first sample separation apparatus 102 or into the second sample separation apparatus 104, depending on a switching state of the fluid valve 110. Also the needle 124 and the seat 126 are provided as a single common needle-seat-arrangement and are configured for transferring fluidic sample into the first sample separation apparatus 102 or the second sample separation apparatus 104.

[0073] The illustrated sample separation system 140 is further configured for pre-compressing the fluidic sample in the sample accommodation volume 108 (initially at ambient pressure) by a corresponding operation of the metering unit 122 before injecting the pre-compressed fluidic sample into the first sample separation apparatus 102 or into the second sample separation apparatus 104 (which may be at a high pressure level, for instance 1400 bar). Advantageously, such a pre-compression of the fluidic sample in the sample accommodation volume 108 may be performed up to a pre-compression pressure value which is intentionally slightly below (for instance 10 bar below) a system pressure value (i.e. the above-mentioned high pressure of for example 1400 bar) of the first sample separation apparatus 102 or the second sample separation apparatus 104. In a corresponding way, the sample separation system 140 is configured for decompressing the sample accommodation volume 108 after injecting fluidic sample from the sample accommodation volume 108 (which may still be at system pressure) into the first sample separation apparatus 102 or the second sample separation apparatus 104 and before accommodating further fluidic sample in the sample accommodation volume 108 (again at ambient pressure).

[0074] Furthermore, the sample separation system 140 shown in FIG. 2 to FIG. 6 comprises a flushing unit 130 configured for flushing fluidic conduits 118 and/or ports 116 of the injector 40 with a flushing fluid which is thereafter guided, optionally via a fluidic restriction 159, into a waste 157. The flushing fluid may also be guided through the sample accommodation volume 108, the needle 124, and the seat 126 as well as through the metering unit 122. Such a flushing may be carried out for cleaning purposes after injection of the fluidic sample from the sample accommodation volume 108 into the first sample separation apparatus 102 or the second sample separation apparatus 104. The waste 157 is connected via schematically illustrated fluid resistance 159 to one of the ports 116 of the fluid valve 110. As can be taken from FIG. 2 as well, the flushing unit 130 is composed of a flushing metering unit 131 and a flushing container 133 comprising a flushing fluid. Furthermore, various check valves 135 are shown as well.

[0075] Referring now in detail to FIG. 2, fluidic sample in sample accommodation volume 108 is injected in a flow path between fluid drive unit 20 and sample separation unit 30 of first sample separation apparatus 102.

[0076] In FIG. 2, the injector 40 is in a feed configuration in which fluidic sample which has previously been loaded in the sample accommodation volume 108 is injected into the first sample separation apparatus 102. For this purpose, the fluidic sample from the sample accommodation volume 108 and mobile phase flowing along a flow path between the fluid drive unit 20 and the separation unit 30 of the first sample separation apparatus 102 are combined at fluidic connection point 120 in static conduit 118′. Thus, mobile phase flows from the fluid drive unit 20 via static groove 118′ and fluidic connection point 120 to separation column 30 of first sample separation apparatus 102. At the same time, the metering unit 122 moves its piston forwardly to thereby press fluidic sample in sample accommodation volume 108 through needle 124, seat 126 and the central port 116 of fluid valve 110 via radial groove conduit 118 and static groove 118′ to fluidic connection point 120. At fluidic connection point 120, the mobile phase and the fluidic sample are combined to flow together as a common fluid stream towards separation unit 30 of first sample separation apparatus 102.

[0077] At the same time, in a completely separate flow path, other mobile phase may be transported from the fluid drive unit 20 via static groove 118′ towards sample separation unit 30 of the second sample separation apparatus 104.

[0078] Referring to FIG. 3, a drawing and pre-compression position of the fluid valve 110 for drawing and pre-compressing fluidic sample to be subsequently separated in first sample separation apparatus 102 is shown.

[0079] The compress state according to FIG. 3 corresponds to an operation mode of the injector 40 after having filled the sample accommodation volume 108 with fluidic sample from sample container 128 and before switching the injector 40 into the operation mode according to FIG. 2 for injecting the fluidic sample into the first sample separation apparatus 102. Prior to starting this compress operation mode according to FIG. 3, the needle 124 may be driven out of the seat 126 and may be immersed in the sample container 128 shown in FIG. 2. Then, the piston of the metering unit 122 may be driven in a backward direction so as to aspirate or draw fluidic sample from the sample container 128 through needle 124 into sample accommodation volume 108 in the valve state according to FIG. 3. Thereafter, the fluidic sample in the sample accommodation volume 108 is still at a low pressure, for instance atmospheric pressure. In order to prevent or at least dampen or reduce a pressure shock occurring when feeding the fluidic sample into the flow path of the first sample separation apparatus 102 (being at system pressure of for example 1400 bar), the needle 124 may firstly be driven back into the seat 126 in the switching state of valve 110 according to FIG. 3. Then, the piston of the metering unit 122 may be moved forwardly so as to pre-compress the fluidic sample in the sample accommodation volume 108, for instance up to a pressure of about 10 bar below system pressure of for instance 1400 bar.

[0080] Referring to FIG. 4, a drawing and pre-compression position of the fluid valve 110 for drawing and pre-compressing fluidic sample to be subsequently separated in second sample separation apparatus 104 is shown.

[0081] The compress state according to FIG. 4 corresponds to an operation mode of the injector 40 after having filled the sample accommodation volume 108 with fluidic sample from sample container 128 and before switching the injector 40 into the operation mode according to FIG. 5 for injecting the fluidic sample into the second sample separation apparatus 104. Prior to starting this compress operation mode according to FIG. 4, the needle 124 may be driven out of the seat 126 and may be immersed in the sample container 128 shown in FIG. 2. Then, the piston of the metering unit 122 may be driven in a backward direction so as to aspirate or draw fluidic sample from the sample container 128 through needle 124 into sample accommodation volume 108 in the valve state according to FIG. 4. Thereafter, the fluidic sample in the sample accommodation volume 108 is still at a low pressure, for instance atmospheric pressure. In order to prevent or at least dampen or reduce a pressure shock occurring when feeding the fluidic sample into the flow path of the second sample separation apparatus 104 (being at system pressure of for example 1400 bar), the needle 124 may firstly be driven back into the seat 126 in the switching state of valve 110 according to FIG. 4. Then, the piston of the metering unit 122 may be moved forwardly so as to pre-compress the fluidic sample in the sample accommodation volume 108, for instance up to a pressure of about 10 bar below system pressure of for instance 1400 bar.

[0082] Referring to FIG. 5, a feed operation mode concerning the second sample separation apparatus 104 is shown.

[0083] FIG. 5 shows a subsequent feed operation mode, i.e. an operation mode in which the drawn and pre-compressed fluidic sample in the sample accommodation volume 108, see FIG. 4, is injected with a feed injection operation mode into the flow path between the fluid drive unit 20 and the separation unit 30 of the second sample separation apparatus 104. This occurs at further fluidic connection point 120′. As shown in FIG. 5, mobile phase is pumped from fluid drive unit 20 through the static arcuate groove corresponding to further fluidic connection point 120′ towards sample separation unit 30 of the second sample separation apparatus 104. The piston of the metering unit 122 is moved forwardly to thereby push the fluidic sample from the sample accommodation volume 108 via needle 124, seat 126, central port 116, radial conduit 118 and radial static conduit 118′ towards fluidic connection point 120′ so as to be combined or unified with the previously described flow of mobile phase originating from the second sample separation apparatus 104. Thus, mobile phase and fluidic sample are transported, under operation of fluid drive unit 20 of second sample separation apparatus 104 towards sample separation unit 30 of second sample separation apparatus 104 for separation of the fluidic sample into fractions.

[0084] Referring to FIG. 6, a flush or purge mode is illustrated.

[0085] FIG. 6 shows the injector 40 and corresponding fluid valve 110 in a purge or flush mode. In this operation mode, the purge or flushing unit 130 may pump flush fluid from flush container 133, driven by flush pump 131 through metering unit 122, seat 126, needle 124, sample accommodation volume 108 and valve arrangement 106 to waste 157.

[0086] In order to operate the sample separation system 140 according to FIG. 2 to FIG. 6 in a cyclic mode, it is for instance possible to firstly draw sample in the draw/compress state according to FIG. 3 for subsequent feeding into first sample separation apparatus 102, to pre-compress the drawn fluidic sample in the sample accommodation volume 108 subsequently, and to switch the injector 40 into the feed configuration according to FIG. 2. Subsequently, the system may be switched back to the configuration according to FIG. 3 for decompressing the sample accommodation volume 108 from system pressure to a smaller pressure (for instance ambient pressure), to prevent pressure shocks, by withdrawing the piston of metering unit 122. Thereafter, it is possible to switch the injector 40 into the purge or flush configuration according to FIG. 6 in order to clean the various components and conduits, as described above. In order to subsequently carry out sample separation in second sample separation apparatus 104, it is then possible to switch the injector 40 into the configuration according to FIG. 4 for drawing fluidic sample into sample accommodation volume 108 and to pre-compress the fluidic sample to avoid pressure shocks. Thereafter, the injector 40 can be switched into the configuration according to FIG. 5 for feeding the drawn fluidic sample from the sample accommodation volume 108 at fluidic connection point 120′ into the separation path between fluid drive unit 20 and separation unit 30 of second sample separation apparatus 104 for separation of the fluidic sample there. Thereafter, the injector 40 may be switched back into the configuration according to FIG. 4 for decompressing the sample accommodation volume 108 from system pressure to a smaller pressure (for instance ambient pressure), to prevent pressure shocks, by withdrawing the piston of metering unit 122. The described procedure can be repeated for any desired sequence of sample separation in any of the sample separation apparatuses 102, 104.

[0087] FIG. 7 and FIG. 8 illustrate injectors 40 operating two sample separation devices 102, 104 according to other exemplary embodiments of the invention.

[0088] The configuration according to FIG. 7 differs from the configuration according to FIG. 2 to FIG. 6 concerning the design of the single fluid valve 110.

[0089] FIG. 8 differs from the embodiment of FIG. 7 by yet another valve design.

[0090] 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.