Patent Application
20230173480
This application claims priority from China Application No. 202111106132.9, filed on Sep. 22, 2021, which application is incorporated herein by reference in its entirety.
The present invention relates to a fluidic system and a method for fraction collection that may be used, at least as a part, in a liquid chromatography system, preferably in a High Performance Liquid Chromatography (HPLC) system. More particularly, it relates to a flush function and a switching valve configured to be used in a fluidic system for fraction collection.
Chromatographic systems are widely used for separating a sample into its various components. More particularly, chromatography is a group of analytical methods for taking a sample (for e.g., a complex mixture) and separating its component substances, or analytes, from one another. In general, analytical chromatography is used to determine the existence, and sometimes the concentration, of analytes in a sample.
Some components, that may be called fractions, separated from a sample may need further sample handling, such as separation and analysis. They may then be collected into target vessels as separated fractions. Embodiments of the present invention relate to a fraction collector, which is a device of a fluidic system, preferably an HPLC system, to collect those target fractions. It may be appreciated that without collection of fractions, chromatography may only yield information on the composition of a sample but may not help to separate the different components. Fraction collection may thus form a part of most chromatographic separation processes. Separation of components may be of interest, for example, in purification of samples, or in chemical testing of different components of a sample, that may be particularly advantageous for medical applications.
In a liquid chromatography system, a sample to be analyzed is pushed by an analytical pump through a separation column with the help of a solvent (that may be called a mobile phase). The separation column may be filled with an adsorbent material (that may be called a stationary phase) that may interact with the component molecules of the sample. Depending on the strength of interaction of different components present in the sample with the stationary phase, they are eluted from the separation column at different times. They may then be detected by a detector downstream of the separation column as peaks at different times, with strongly interacting components eluting as peaks later in time than weakly interacting components.
As described above, it may be advantageous to collect the fractions eluted from the separation column downstream of the detector for further analysis. For example, the sample may comprise a plurality of components that all interact weakly with a first stationary phase in the separation column. A mixture of these components may then be eluted relatively early in the separation process. It may then be advantageous to repeat the separation process with a different stationary phase to allow for further analysis of this mixture that interacted only weakly with the first stationary phase. This may be of particular advantage in cases where only a limited volume of sample may be used for analysis and fractions may be collected from a first separation to conserve the volume of sample.
Collection of fractions may be based on the detector signal, for example, on the identification of certain peaks, or on retention times in the separation column, for example, collection of a fraction that is eluted from the separation column between some start time and end time. These may be classified as peak-based and time-based fractionation, respectively. Time-based fractionation may be advantageously employed when the fractions to be collected have known, stable retention times or known, stable peak shapes such that a start and stop of the fraction collection process may be based on, for example, a slope of the peak shape. It may also be particularly advantageous for complex samples, where accurate differentiation between peaks may be difficult so that a peak-based method may yield inaccurate collection. However, time-based fractionation may provide low resolution as all the components that may be eluted in the time window chosen for collection will be collected in the fraction.
Peak-based fractionation, on the other hand, may be advantageous when retention times and/or peak shapes are not known or are unstable. However, it may provide higher resolution than time-based fractionation, since only known peaks are collected as fractions.
A relevant consideration for fraction collecting systems, that may be called fraction collectors, may be minimization of fluid volume lost to waste when switching reservoirs for collecting more than one fraction, for example. Another consideration may be the purity of fractions collected, for example, for fractions that may be closely spaced in the separation process. An example of mixing may be a carry-over which may result from incomplete emptying of a collection needle (for example) at the end of collecting a previous fraction.
In view of the above, it is generally desirable to have a technology allowing sample fractioning. In other words, it is generally desirable to have technology allowing samples eluting at different times to be collected separately from one another. These are aims of the present invention. More particularly, it is an aim of the present invention to provide a technology with a high recovery rate and less or almost no carry-over for fraction collection, especially for closely placed fractions/peaks and very small volume fraction collection.
At least some of these objects are met by the present invention.
In a first aspect, the present invention relates to a fluidic system, wherein the fluidic system comprises a switching valve comprising a plurality of ports, wherein the switching valve is configured for connecting the ports in different configurations, wherein the ports comprise a first port and a second port, an inlet line directly connected to the first port, a collection device directly connected to the second port, and wherein the fluidic system is configured to assume a collection configuration wherein the first port and the second port are connected. This configuration may represent a typical configuration of a fluidic system for fraction collection. Eluates from an analysis setup upstream of the inlet line may flow into the collection device and be collected into a collection reservoir subsequently. A delay volume between elution from the analytical detector and appearance of the fraction at the collection device may, for example, allow time for aligning the collection device over the collection reservoir that may be advantageous. Generally, in this specification, when a unit is said to be directly connected to a port of the switching valve (e.g., as is the inlet line to the first port), this denotes that there is a connection between the unit and the port, without there being another port of the switching valve being present in this connection.
The ports may comprise a third port and a fourth port, and the fluidic system may comprise a buffer section directly connected to the third port and the fourth port. The fluidic system with these components may be used to carry out collection of multiple fractions with a high recovery rate. In a typical fraction collection system, when switching from collection of one fraction to the next fraction, an intermediate step of letting fluid out into a waste may be employed to ensure that there is no mixing of fractions. However, as will be described below, a buffer section may help to collect different fractions, e.g., with lesser volume being discharged into the waste. In other words, the buffer section may prevent unwanted fractions/peaks from flowing into the collection device. Mixed fractions or peaks may exist only inside the buffer section. Different fractions/peaks, even closely placed fractions/peaks may be isolated, while reducing carry-over at the same time, using the buffer section.
The fluidic system may be configured to assume a buffer configuration, wherein the first port and the third port are connected and the fourth port and the second port are connected.
The ports may comprise a pump port directly connected to a pump and a waste port directly connected to waste. A pump, that may be a piston pump, connected with one port of the switching valve may be of advantage in cleaning up the buffer section between collection of different fractions. It may be filled up with the clean mobile phase (in case the fluidic system comprises an HPLC system) or with an additional cleaning/wash solvent first. Then it may be used to wash the buffer section fluidically connected to the switching valve. Cleaning up the buffer section may ensure that it is full of clean solvent or clean mobile phase.
The fluidic system described above may be configured to assume a buffer section wash configuration, wherein the pump port and the fourth port are connected and the third port and the waste port are connected. This may allow the buffer section to be flushed. As described above, mixed fractions/peaks may in some embodiments exist only inside the buffer section. After flushing is complete, the mixed fractions/peaks would be cleaned up and washed into the waste, for example, by actuating a piston of the pump. The buffer section may then be refilled with clean solvent or clean mobile phase already stored inside the cavity of the (piston) pump, for example.
The ports may comprise a discharge port directly connected to waste.
The fluidic system described above may be further configured to assume a discharge configuration, wherein the first port is connected to the discharge port.
The fluidic system as described above may be configured such that the buffer wash configuration and the discharge configuration are identical. Connecting the discharge port as well as the waste port directly to waste may be of advantage in allowing washing and/or refilling of the buffer section at the same time as the fluidic system is prepared for collection of a next fraction, when the buffer section is used in between collection of two fractions, for example. While the collection device is moved between collection reservoirs, for example, the flow through the inlet line may be directed into the waste via the discharge port. At the same time, the buffer section may also dispense its contents into the waste. This may help to improve the efficiency of the fraction collection process.
The fluidic system may further comprise a solvent reservoir configured to be connected to a port of the switching valve and to allow a solvent to be drawn out of it. The solvent may be the mobile phase used in an HPLC system flow in case the fluidic system is an HPLC system. The mobile phase may thus be additionally used as a flush solvent to flush out or dispense remaining liquid inside the collection device, that may comprise a collection tube and a collection needle, instead of an additional wash solvent provided separately for this purpose. This may help reduce complexity of the fluidic system, ease operations, and lead to less wastage.
The ports may comprise a solvent port directly connected to the solvent reservoir.
The fluidic system described above may be configured to assume a pump load configuration wherein the solvent port and the pump port are connected. This may allow the pump to easily draw up solvent from the solvent reservoir.
The pump load configuration may be identical to the collection configuration. As described above, in the buffer section wash configuration the buffer section may be washed and/or refilled with a solvent already stored inside the cavity of the (piston) pump. An advantage of the pump load configuration and the collection configuration may be that subsequent to refilling of the buffer section with clean solvent the pump may be refilled with clean solvent while at the same time collecting a fraction. This may help to improve the efficiency of the collection process.
The switching valve may comprise a first connecting element for connecting the ports. It may be advantageous for the connecting elements to have a dead volume significantly close to zero between the two ports they connect.
The first connecting element may connect the first port and the second port in the collection configuration, the first port and the discharge port in the discharge configuration, and the first port and the third port in the buffer configuration.
The switching valve may comprise a second connecting element for connecting the ports. The second connecting element may connect the solvent port and the pump port in the collection configuration, the fourth port and the pump port in the discharge configuration, and the second port and the fourth port in the buffer configuration.
The switching valve may comprise a third connecting element for connecting the ports. The third connecting element may connect the third port and the discharge port in the collection configuration, the third port and the waste port in the discharge configuration, and the waste port to a dead end in the buffer configuration.
The fluidic system may further comprise a wash section configured to receive the collection device. This may be helpful to clean the collection device between collection of different fractions leading to less carry-over.
The fluidic system may further comprise a first collection reservoir, wherein the fluidic system may be configured to position the collection device to expel a fluid into the first collection reservoir.
The fluidic system may comprise a second collection reservoir, wherein the fluidic system may be configured to position the collection device to expel a fluid into the second collection reservoir.
The collection device may comprise a collection needle. The collection needle may be chosen according to the samples are to be collected. A relevant consideration may be the viscosity or surface tension of the samples as a higher surface tension would imply a greater tendency to cling to the surface of the collection needle.
The collection device may comprise a collection tube.
The fluidic system may further comprise a flow sensor configured to measure a flow rate of fluid flowing through it.
The fluidic system as described above may be configured such that the flow sensor is configured to measure the flow rate of fluid being discharged into the waste. Measurement of the flow rate may be used to determine the time taken by eluates to flow from the analytical detector to the collection device. This flow time may be of relevance in determining the speed with which the collection needle may be positioned over a collection reservoir, or the speed at which the switching valve may be switched between different configurations as part of a fraction collection process.
The fluidic system may further comprise a control unit configured to switch between different configurations of the fluidic system.
The control unit may be configured to switch the configuration of the switching valve to switch the configuration of the fluidic system.
Switching the configuration of the switching valve may be based on a measurement of the flow rate of fluid being discharged into the waste. The control unit may be a microprocessor and may use measurements from the flow sensor, for example, to determine when to switch the configuration of the switching valve. For example, once a first fraction has been collected and a second fraction to be collected is detected upstream of the inlet line, the control unit may switch the switching valve from a collection configuration to a buffer section configuration, such that flow of the fluid is routed through the buffer section. This would allow the first fraction to fill up in the buffer section with clean solvent and may lead to less loss of sample.
The control unit may be further configured to position the collection device to expel fluid into a collection reservoir. For example, once a first fraction has been collected and a second fraction is to be further collected, the control unit may cause the collection device to move to the correct position above the collection reservoir for the second fraction. It may be particularly advantageous to use a control unit for this process, in order to ensure that the timing is accurately controlled and reproducible between different collections of fractions.
The pump as described above may be a metering device. It may comprise a piston and a housing. Or, it may be a flush pump. It may further comprise a container containing a pressurized gas.
The fluidic system may further comprise an analytical detector upstream of the first port. The analytical detector may serve to indicate the arrival of different fractions to the control unit, for example, so that the switching valve and the collection device may be brought into an appropriate configuration for collection of the fractions in their corresponding collection reservoirs.
The fluidic system described above may be a liquid chromatography system, preferably a high performance liquid chromatography system.
The solvent as described above may be identical to a mobile phase used in the liquid chromatography system. This may be different from a typical fraction collection process where a special solvent may need to be provided to wash the collection tube and collection device so that more operations and/or specific solvents may be needed. Alternatively, no washing solvent may be used for washing the collection device which may lead to higher carry-over.
The solvent as described above may be different from the mobile phase used in the liquid chromatography system. This may, however, not be a preferred embodiment owing to additional complexity of operations and system involved in using an additional solvent.
The solvent as described above may be any of an organic solvent, an inorganic solvent, a polar solvent, or a non-polar solvent.
Switching the switching valve as described above from the discharge configuration to the collection configuration may comprise rotating the switching valve by an angle between 10° and 80°, preferably between 20° and 70°, and further preferably between 30° and 60°. Smaller angles may help to switch the switching valve quickly. However, they may also make placement of ports on the switching valve more complex.
Switching the switching valve as described above from the collection configuration to the buffer configuration may comprise rotating the switching valve by an angle between 10° and 80°, preferably between 20° and 70°, and further preferably between 30° and 60°.
The switching valve as described above may comprise ports such that the second port is between the fourth port and the discharge port, the third port is between the discharge port and the waste port, and the solvent port is between the waste port and the pump port.
The switching valve as described above may comprise ports such that the fourth port is between the second port and the pump port, the discharge port is between the second port and the third port, the waste port is between the third port and the solvent port, and the pump port is between the solvent port and the fourth port.
The switching valve as described above may comprise ports such that the first port is at substantially the same distance from the other ports.
The wash section described above may be further configured to draw the solvent from the solvent reservoir for washing the outer surface of the collection needle. This may help to simplify the system as the same solvent may be used to wash the outer surface of the collection needle as that used for cleaning the buffer section.
The collection device described above may be configured for one-dimensional positioning. For example, this may be the case when a plurality of collection reservoirs are placed next to each other in a one-dimensional array. This may allow for a simpler controlling procedure for moving the collection device over the collection reservoirs. However, it may also limit the number of collection reservoirs that may be filled with fractions.
Alternatively, the collection device may be configured for two-dimensional positioning. This may allow for a larger number of collection reservoirs to be filled with fractions with only a small movement of the collection device. However, as will be appreciated, this may involve a more complex alignment procedure of the collection device over the collection reservoir.
According to a second aspect, the present invention also relates to a switching valve. The switching valve comprises a plurality of ports, and the switching valve is configured for connecting the ports in different configurations. The ports comprise a first port, a second port, and a discharge port, the switching valve comprises a stator, the stator comprises the plurality of ports, and the switching valve comprises a rotor, wherein the rotor comprises at least one connecting element for connecting the ports in the different configurations. When the term discharge port is used in conjunction with the switching valve, it should be understood that this is for conformity with the terminology used when describing the system only. That is, the term discharge port only stipulates that the respective port can in principle also be used as a discharge port, without this necessitating that the port is actually used as such a discharge port. Corresponding considerations also apply to the terms collection configuration, discharge configuration, and buffer configuration when used to describe the valve. Again, these terms are mainly used to disambiguate the different configurations, without there being the necessity that the respective configurations are actually used for collection, discharge, and buffer functionalities.
The at least one connecting element may be at least one groove.
One of the at least one element may comprise an L-shaped groove comprising a radial section and a circumferential section.
The at least one element comprise 3 connecting elements and each of the 2 other connecting elements may lie on opposite sides of the L-shaped groove.
The rotor may comprise a groove connected to the second port and extending between the second port and the discharge port.
The rotor may comprise a third port.
The rotor may comprise a groove connected to the discharge port and extending between the discharge port and the third port.
A sub set of the plurality of ports may lie on a circle around the first port.
The switching valve may be configured to assume a collection configuration fluidly connecting the first port and the second port.
The switching valve may be configured to assume a discharge configuration fluidly connecting the first port and the discharge port.
The switching valve may be configured to transition from the collection configuration to the discharge configuration such that the first port is always connected to the second port or the discharge port during the transition.
The switching valve may be configured to assume a buffer configuration, wherein the first port and the third port are connected.
The switching valve may be configured to transition from the discharge configuration to the buffer configuration such that the first port is always connected to the discharge port or to the third port during the transition.
The fluid connection between the first port and the second port in the collection configuration may be dead volume free.
The fluid connection between the first port and the discharge port in the discharge configuration may be free of dead volumes.
The fluid connection between the first port and the third port in the buffer configuration may comprise free of dead volumes.
In the described system, the switching valve may be realized according to the switching valve of the second aspect.
According to a third aspect, the present invention relates to a method of operating the fluidic system as described above wherein the method comprises the fluidic system assuming the collection configuration and causing a fluid flow through the inlet line, the first port, the second port, and the collection device into the first collection reservoir in the collection configuration.
The method may comprise the fluidic system assuming the buffer configuration and causing a second fluid flow flowing through the inlet line, the first port, the third port, the buffer section, the fourth port, the second port, and the collection device in the buffer configuration.
The second fluid flow as described above may cause fluid to flow into the first collection reservoir. Thus, the buffer section may be used to direct fluid flow close to the end of collection of one fraction and before starting collection of the next fraction. This may help to collect the two fractions, even if they are closely placed, without contaminating one with the other. The contaminated fractions exist only inside the buffer section and may be washed in a subsequent buffer section wash configuration.
The method may further comprise the fluidic system assuming the buffer section wash configuration after the fluidic system assumes the buffer configuration, and the fluidic system causing a washing flow through the pump port, the fourth port, the buffer section, the third port, the waste port and towards the waste in the buffer section wash configuration.
The method may further comprise the fluidic system again assuming the collection configuration after the fluidic system assumes the buffer section wash configuration, and the fluidic system causing a fluid flow through the inlet line, the first port, the second port, and the collection device into the second collection reservoir in the collection configuration.
The method may further comprise measuring a dead volume of the flow path of the fluid in any configuration of the fluidic system.
The method may further comprise using the dead volume measured in a configuration and the flow rate of fluid measured by the flow sensor to determine the time to switch the configuration of the fluidic system.
The method may further comprise using the control unit to switch the configuration of the fluidic system.
The method may further comprise switching the position of the collection device to switch the configuration of the fluidic system.
The method may further comprise switching the configuration of the switching valve to switch the configuration of the fluidic system. For example, the switching valve may be switched between the collection configuration, the buffer section configuration, and the buffer section wash configuration, where in each of these configurations the plurality of connecting elements connect different pairs of ports.
The method may further comprise the fluidic system assuming the discharge configuration after the fluidic system assumes the collection configuration, and the fluidic system causing a washing flow through the inlet line, the first port, and towards the waste in the discharge configuration. This may be a configuration where the fluidic system is used to collect fractions without an intermediate buffer section wash configuration. Omitting the buffer section wash configuration may help to further improve efficiency of the collection process.
The method may further comprise the fluidic system again assuming the collection configuration after the fluidic system assumes the discharge configuration, and the fluidic system causing a fluid flow through the inlet line, the first port, the second port, and the collection device into the second collection reservoir in the collection configuration.
When the fluid flows into the first collection reservoir, a first sample constituent may be collected in the first collection reservoir, and when the fluid flows into the second collection reservoir, a second sample constituent may be collected in the second sample reservoir.
According to a third aspect, the present invention relates to a computer program product comprising instructions configured to, when run on a control unit of the fluidic system, cause the fluidic system to perform the method according to any of the preceding method embodiments. For example, such a product may comprise instructions to switch the switching valve to, for example, a collection configuration once a fraction appears at the analytical detector. Or, if a first fraction was being collected and a second fraction appears at the analytical detector, the control unit may be programmed to switch the switching valve to a buffer section configuration. Similarly, towards the end of collection of a first fraction, the control unit may be programmed to position the collection device over a second collection reservoir.
Overall, embodiments of the present technology may thus relate to a fluidics design, which makes it possible to collect closely placed fractions/peaks with flush function (flush out or dispense remaining liquid inside collection tube and needle to improve recovery rate and reduce carry over). In embodiments, a valve, which may be referred to as a fraction valve (realized as a multi-port rotary valve) may be used for the fraction collector, embedded inside the product to divert HPLC system flow into waste, collection vessels or flush position (still connecting to collection vessels) by switching at a very high speed over at least three positions: waste position, collection position, and flush position.
Below, system embodiments will be discussed. These embodiments are abbreviated by the letter “S” followed by a number. Whenever reference is herein made to system embodiments, these embodiments are meant.
S1. A fluidic system, wherein the fluidic system comprises
S2. The fluidic system according to the preceding embodiment,
S3. The fluidic system according to the preceding embodiment,
S4. The fluidic system according to any of the preceding embodiments,
S5. The fluidic system according to the preceding embodiment and with the features of embodiment S2,
S6. The fluidic system according to any of the preceding embodiments,
S7. The fluidic system according to the preceding embodiment,
S8. The fluidic system according to the preceding embodiment and with the features of embodiment S5, wherein the buffer wash configuration and the discharge configuration are identical.
S9. The fluidic system according to any of the preceding embodiments, wherein the fluidic system further comprises a solvent reservoir configured to be connected to a port of the switching valve and to allow a solvent to be drawn out of it.
S10. The fluidic system according to the preceding embodiment,
S11. The fluidic system according to the preceding embodiment and with the features of embodiment S4,
S12. The fluidic system according to the preceding embodiment, wherein the pump load configuration is identical to the collection configuration.
S13. The fluidic system according to any of the preceding embodiments, wherein the switching valve comprises a first connecting element for connecting the ports.
S14. The fluidic system according to the preceding embodiment, wherein the first connecting element connects the first port and the second port in the collection configuration.
S15. The fluidic system according to any of the 2 preceding embodiments, wherein the first connecting element connects the first port and the discharge port in the discharge configuration.
S16. The fluidic system according to any of the preceding embodiments with the features of embodiments S3 and S13, wherein the first connecting element connects the first port and the third port in the buffer configuration.
S17. The fluidic system according to any of the preceding embodiments, wherein the switching valve comprises a second connecting element for connecting the ports.
S18. The fluidic system according to the preceding embodiment and with the features of embodiments S4 and S10, wherein the second connecting element connects the solvent port and the pump port in the collection configuration.
S19. The fluidic system according to any of the 2 preceding embodiments and with the features of embodiments S2 and S4, wherein the second connecting element connects the fourth port and the pump port in the discharge configuration.
S20. The fluidic system according to any of the preceding embodiments with the features of embodiments S2 and S17, wherein the second connecting element connects the second port and the fourth port in the buffer configuration.
S21. The fluidic system according to any of the preceding embodiments, wherein the switching valve comprises a third connecting element for connecting the ports.
S22. The fluidic system according to the preceding embodiment, wherein the third connecting element connects the third port and the discharge port in the collection configuration.
S23. The fluidic system according to the penultimate embodiment and with the features of embodiments S3 and S7, wherein the third connecting element connects the third port and the waste port in the discharge configuration.
S24. The fluidic system according to any of the preceding embodiments with the features of embodiment S3, S4, and S21, wherein the third connecting element connects the waste port to a dead end in the buffer configuration.
S25. The fluidic system according to any of the preceding embodiments, wherein the fluidic system comprises a wash section configured to receive the collection device.
S26. The fluidic system according to any of the preceding embodiments, wherein the fluidic system comprises a first collection reservoir, and wherein the fluidic system is configured to position the collection device to expel a fluid into the first collection reservoir.
S27. The fluidic system according to any of the preceding embodiments, wherein the fluidic system comprises a second collection reservoir, and wherein the fluidic system is configured to position the collection device to expel a fluid into the second collection reservoir.
S28. The fluidic system according to any of the preceding embodiments, wherein the collection device comprises a collection needle.
S29. The fluidic system according to any of the preceding embodiments, wherein the collection device comprises a collection tube.
S30. The fluidic system according to any of the preceding embodiments, wherein the fluidic system further comprises a flow sensor configured to measure a flow rate of fluid flowing through it.
S31. The fluidic system according to the preceding embodiment and with the features of embodiment S4, wherein the flow sensor is configured to measure the flow rate of fluid being discharged into the waste.
S32. The fluidic system according to any of the preceding embodiments, wherein the fluidic system further comprises a control unit configured to switch between different configurations of the fluidic system.
S33. The fluidic system according to the preceding embodiment, wherein the control unit is configured to switch the configuration of the switching valve to switch the configuration of the fluidic system.
S34. The fluidic system according to any of the preceding embodiments with the features of embodiments S31 and S32, wherein switching the configuration of the switching valve is based on a measurement of the flow rate of fluid being discharged into the waste.
S35. The fluidic system according to any of the preceding embodiments and with the features of embodiment S32 and any of embodiments S26, and S27, wherein the control unit is further configured to position the collection device to expel fluid into a collection reservoir.
S36. The fluidic system according to any of the preceding embodiments and with the features of embodiment S4, wherein the pump is a metering device.
S37. The fluidic system according to any of the preceding embodiments and with the features of embodiment S4, wherein the pump comprises a piston and a housing.
S38. The fluidic system according to any of the preceding embodiments and with the features of embodiment S4, wherein the pump is a flush pump.
S39. The fluidic system according to any of the preceding embodiments and with the features of embodiment S4, wherein the pump comprises a container containing a pressurized gas.
S40. The fluidic system according to any of the preceding embodiments, wherein the fluidic system further comprises an analytical detector upstream of the first port.
S41. The fluidic system according to any of the preceding embodiments, wherein the fluidic system is a liquid chromatography system, preferably a high performance liquid chromatography system.
S42. The fluidic system according to the preceding embodiment and with the features of embodiment S9, wherein the solvent is identical to a mobile phase used in the liquid chromatography system.
S43. The fluidic system according to the penultimate embodiment and with the features of embodiment S9, wherein the solvent is different from the mobile phase used in the liquid chromatography system.
S44. The fluidic system according to any of the preceding embodiments and with the features of embodiment S9, wherein the solvent is an organic solvent.
S45. The fluidic system according to any of the preceding embodiments and with the features of embodiment S9, wherein the solvent is an inorganic solvent.
S46. The fluidic system according to any of the preceding embodiments and with the features of embodiment S9, wherein the solvent is a polar solvent.
S47. The fluidic system according to any of the preceding embodiments and with the features of embodiment S9, wherein the solvent is a non-polar solvent.
S48. The fluidic system according to any of the preceding embodiments with the features of embodiment S7, wherein switching the switching valve from the discharge configuration to the collection configuration comprises rotating the switching valve by an angle between 10° and 80°, preferably between 20° and 70°, and further preferably between 30° and 60°.
S49. The fluidic system according to any of the preceding embodiments with the features of embodiment S3, wherein switching the switching valve from the collection configuration to the buffer configuration comprises rotating the switching valve by an angle between 10° and 80°, preferably between 20° and 70°, and further preferably between 30° and 60°.
S50. The fluidic system according to any of the preceding embodiments with the features of embodiments S2, S4, S6, and S10, wherein
S51. The fluidic system according to any of the preceding embodiments with the features of embodiments S2, S4, S6, and S10, wherein
S52. The fluidic system according to any of the 2 preceding embodiments, wherein the first port is at substantially the same distance from the other ports.
S53. The fluidic system according to any of the preceding embodiments and with the features of embodiments S9, S25, and S28, wherein the wash section is further configured to draw the solvent from the solvent reservoir for washing the outer surface of the collection needle.
S54. The fluidic system according to any of the preceding embodiments, wherein the collection device is configured for one-dimensional positioning.
S55. The fluidic system according to any of the preceding embodiments but without the features of the preceding embodiment, wherein the collection device is configured for two-dimensional positioning.
Below, valve embodiments will be discussed. These embodiments are abbreviated with the letter V followed by a number. Whenever reference is herein made to valve embodiments, these embodiments are meant.
V1. A switching valve, wherein the switching valve comprises a plurality of ports, wherein the switching valve is configured for connecting the ports in different configurations, wherein the ports comprise a first port (0), a second port (2), and a discharge port (3),
V2. The switching valve according to the preceding embodiment, wherein the at least one connecting element is at least one groove.
V3. The switching valve according to any of the preceding valve embodiments, wherein one of the at least one element comprises an L-shaped groove comprising a radial section and a circumferential section.
V4. The switching valve according to the preceding embodiment, wherein the at least one element comprise 3 connecting elements and each of the 2 other connecting elements lie on opposite sides of the L-shaped groove.
V5. The switching valve according to any of the preceding valve embodiments, wherein the rotor comprises a groove connected to the second port and extending between the second port and the discharge port.
V6. The switching valve according to any of the preceding valve embodiments, wherein the rotor comprises a third port.
V7. The switching valve according to the preceding embodiment and with the features of embodiment V5, wherein the rotor comprises a groove connected to the discharge port and extending between the discharge port and the third port.
V8. The switching valve according to any of the preceding valve embodiments, wherein a sub set of the plurality of ports lie on a circle around the first port.
V9. The switching valve according to any of the preceding valve embodiments, wherein the switching valve is configured to assume a collection configuration fluidly connecting the first port and the second port.
V10. The switching valve according to any of the preceding valve embodiments, wherein the switching valve is configured to assume a discharge configuration fluidly connecting the first port and the discharge port.
V11. The switching valve according to the preceding embodiment and with the features of the penultimate embodiment, wherein the switching valve is configured to transition from the collection configuration to the discharge configuration such that the first port is always connected to the second port or the discharge port during the transition.
V12. The switching valve according to any of the preceding embodiments and with the features of embodiment V6, wherein the switching valve is configured to assume a buffer configuration, wherein the first port and the third port are connected.
V13. The switching valve according to the preceding embodiment and with the features of embodiment V10, wherein the switching valve is configured to transition from the discharge configuration to the buffer configuration such that the first port is always connected to the discharge port or to the third port during the transition.
V14. The switching valve according to any of the preceding embodiments with the features of embodiment V9, wherein the fluid connection between the first port and the second port in the collection configuration is dead volume free.
V15. The switching valve according to any of the preceding embodiments with the features of embodiment V10, wherein the fluid connection between the first port and the discharge port in the discharge configuration is dead volume free.
V16. The switching valve according to any of the preceding embodiments with the features of embodiment V12, wherein the fluid connection between the first port and the third port in the buffer configuration is dead volumes free.
S56. The system according to any of the preceding system embodiments, wherein the switching valve is realized according to any of the preceding valve embodiments.
Below, method embodiments will be discussed. These embodiments are abbreviated by the letter “M” followed by a number. Whenever reference is herein made to method embodiments, these embodiments are meant.
M1. A method of operating the fluidic system according to any of the preceding embodiments with the features of embodiment S26, wherein the method comprises
M2. The method according to the preceding embodiment, wherein the fluidic system comprises the features of embodiment S3,
M3. The method according to the preceding embodiment,
M4. The method according to any of the 2 preceding embodiments, wherein the fluidic system comprises the features of embodiment S5,
M5. The method according to the preceding embodiment, wherein the fluidic system comprises the features of embodiment S27,
M6. The method according to any of the preceding method embodiments, wherein the method further comprises measuring a dead volume of the flow path of the fluid in any configuration of the fluidic system.
M7. The method according to the preceding embodiment, wherein the fluidic system comprises the features of embodiment S30, wherein the method further comprises using the dead volume measured in a configuration and the flow rate of fluid measured by the flow sensor to determine the time to switch the configuration of the fluidic system.
M8. The method according to any of the preceding method embodiments, wherein the fluidic system comprises the features of embodiment S32, wherein the method further comprises using the control unit to switch the configuration of the fluidic system.
M9. The method according to any of the preceding method embodiments, wherein the fluidic system comprises the features of embodiment S35, wherein the method further comprises switching the position of the collection device to switch the configuration of the fluidic system.
M10. The method according to any of the preceding method embodiments, wherein the fluidic system comprises the features of embodiment S33, wherein the method further comprises switching the configuration of the switching valve to switch the configuration of the fluidic system.
M11. The method according to any of the preceding method embodiments, wherein the fluidic system comprises the features of embodiment S7,
M12. The method according to the preceding embodiment, wherein the fluidic system comprises the features of embodiment S27,
M13. The method according to any of the preceding method embodiments with the features of embodiment M5 and/or M12, wherein when the fluid flows into the first collection reservoir, a first sample constituent is collected in the first collection reservoir, and when the fluid flows into the second collection reservoir, a second sample constituent is collected in the second sample reservoir.
P1. A computer program product comprising instructions configured to, when run on a control unit of the fluidic system, cause the fluidic system to perform the method according to any of the preceding method embodiments.
The fluidic system 10, that may also be referred to as a fraction collector, may further comprise a rotary valve 200 (that may be called a fraction or switching valve) that comprises a plurality of ports (0 to 8, where the first port 0 is directly connected to the detector 900 via an inlet line and carries the mixture eluted from the separation column) and a plurality of connecting elements 210, that may be called the first connecting element 210b, the second connecting element 210a, and the third connecting element 210c. Each of the connecting elements 210 is configured to changeably connect the plurality of ports of the valve 200. The system 10 further comprises a waste reservoir 700 directly connected to a discharge port 3 and a waste port 5 of the valve. The system 10 may also comprise a pump 100 (that may be a flush pump, or a container with pressurized gas, or a metering device) directly connected to a pump port 8, and a collection device 300, that may comprise a collection tube 320 and a collection needle 310. The collection device 300 may be directly connected to the second port 2. The pump 100 may be configured to provide an operating pressure of 8 bar, for example. It may further comprise an internal cavity that may store the cleaning/wash solvent. The volume of the internal cavity may, for example, be 1 ml. The depicted system 10 further comprises a wash section 600 that may be used to wash the collection needle 310, and a buffer section 400, that may be a buffer ring, directly connected to the third port 4 and to the fourth port 1 of the switching valve 200.
When a component is said to be directly connected to a port of the switching valve 200, this should denote a fluid connection between the component and the respective port of the switching valve 200, without there being another port present in the connection between the component and the respective port. For example, in the configuration depicted in
With further regard to the Figures, it is noted that in the depicted Figures, no port 6 is depicted. Thus, whenever mention is made of ports 0 to 8, it may be understood that the port 6 is absent from the switching valve. Alternatively, it may be present on the switching valve but may not be involved in carrying out the method described below.
The fluidic system 10 further comprises a plurality of collection reservoirs 500 (500a, 500b, 500c), which may also be referred to as vials, that may be used to collect a plurality of fractions eluted from a separation column upstream of the detector 900, and a solvent reservoir 50 that may comprise a solvent that may be used for washing the fluidics in the fluidic system 10, such as the buffer section 400 or the collection device 300. The collection needle 310 may be configured to be moved into one of the plurality of collection reservoirs 500 when needed. In embodiments, the collection reservoirs 500 may be arranged in a 1-dimensional or 2-dimensional array and the motion of the collection needle 310 may be appropriately configured. The solvent reservoir 50 may be further connected directly to the wash section 600 to provide a wash solvent for washing the outer surface of the connection needle 310. That is, in the example depicted in
The fluidic system 10 may further comprise at least one flow sensor 800 (or a plurality of flow sensors). At least one of these flow sensors 800 may be installed on the waste line, i.e., upstream of the waste reservoir 700 and configured to measure a flow rate of fluid that flows into the waste reservoir 700. This may help to determine the time at which a fraction to be collected arrives into the collection needle 310 as follows: a delay volume of the fluidics connecting the outlet of the detector 900 to the collection needle 310 may be determined, e.g., at the start of the separation process. Then, based on the flow rate of fluid being discharged into the waste reservoir 700, the time needed for a peak to travel to the collection needle 310 after being eluted from the detector 900 may be determined, for example. This would then represent an upper limit for the time needed for accurately switching the switching valve 200 and bringing the collection needle 310 to an empty collection reservoir 500, for example, after detecting the peak in the detector 900.
The fluidic system 10 may further comprise a control unit 60, configured to control the rotation of the rotor based on feedback from the flow sensor 800, where the data connection is depicted as dotted lines. This may allow switching the operating modes of the fluidic system 10 to a suitable mode as described further below.
The control unit 60, which may also be referred to as controller 60, can be operatively connected to other components, as depicted by dotted lines in
The controller 60 can include a data processing unit and may be configured to control the system and carry out particular method steps. The controller can send or receive electronic signals for instructions. The controller can also be referred to as a microprocessor. The controller can be contained on an integrated-circuit chip. The controller can include a processor with memory and associated circuits. A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC), or sometimes up to a plurality of integrated circuits, such as 8 integrated circuits. The microprocessor may be a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory and provides results (also in binary form) as output. Microprocessors may contain both combinational logic and sequential digital logic. Microprocessors operate on numbers and symbols represented in the binary number system.
While the controller 60 is only depicted in
Additionally, the fluidic system 10 may be further configured to be used together with a computer program product that may comprise instructions for causing the control unit to switch the switching valve 200 and/or to move the collection needle 310 over a designated collection reservoir 500.
It may also be noted that the flush solvent used to dispense remaining liquid inside the collection device 300 and collection needle 310 depicted in
Thus, in other words, the fluidic system 10 as depicted in
It is an aim of the present invention to use the additional components as depicted in
The switching valve 200 may further comprise a rotating section, that may be called a rotor, that may comprise a plurality of connecting elements 210, for e.g., 3 connecting elements, 210a, 210b, 210c, configured to provide a fluidic connection between ports of the stator that each of them connects. The connecting elements may be positioned on the rotor as shown in
The rotor may be configured to be rotated about an axis perpendicular to the plane of the rotor and passing through its center. The angle by which the rotor may be allowed to rotate may be determined by the relative position of the connecting elements 210 and the ports 0 to 8. For example, in the configuration depicted in
A further configuration is depicted in
In the depicted embodiments, the connecting elements 210a, 210b, and 210c are depicted with particular shapes. With regard to
In the depicted embodiment, the first connecting element 210b is depicted to be hook shaped. That is, it comprises a straight section and an arcuate section. However, it will be understood that this is only one example and that the first connecting element may also be realized in other manners, e.g., it may only comprise a straight section.
Furthermore, the second and third connecting elements 210a, 210c, are depicted to be arcuate. Again, it should be understood that this is merely exemplary and that they may also be shaped differently (e.g., they may be straight).
Furthermore, as depicted in the Figures, the circumferential ports 1 to 7 may preferably be located at equal distances to one another (with the exception of ports 5 and 7). Further still, as depicted, e.g., in
In other words, the switching valve 200 described above may be employed in a fluidic system 10 for fraction collection. It may be embedded inside an HPLC system, for example, to divert HPLC system flow into a waste reservoir 700, collection reservoirs 500, or a buffer section 400 (while the fluidic system 10 is still connected to the collection reservoirs 500) by switching at high speeds over the three work configurations/positions described above: a discharge configuration (
In this configuration, eluates from the detector 900 are discharged into the waste reservoir 700 while the pump 100 may be used to simultaneously fill up the buffer section 400 with a cleaning solvent that may have been drawn up from the solvent reservoir 50 in a previous step. More particularly, the pump 100 may cause a flow through port 8, port 1, buffer section 400, port 4 and port 5 towards the waste reservoir 700. However, as described, there may also be a valve (e.g., a two way valve) in the connection between the port 5 and the waste reservoir 700. By means of this valve, the fluid flow may also be directed towards the wash port 600 and to the waste reservoir which is also connected to port 3. Thus, the solvent flowing through the buffer section 400 may also be used to wash the wash port 600.
This may allow the buffer section 400 to be prepared for a subsequent step wherein a fraction eluted from the separation column upstream of the detector 900 may be collected into one of the collection reservoirs 500 via the buffer section 400.
A typical workflow employing the fluidic system 10 as described above to collect two fractions will now be described with reference to
In a first preparation step, that may be carried out before the start of the separation, the fluidic system 10 may be used to wash the buffer section 400 and the collection needle 310 as shown in
Once solvent has been drawn up into the pump 100, it may be pushed into the buffer section 400. This is depicted in
The volume of the pump 100 may be chosen to be large enough that the buffer section 400 is reliably filled with the solvent at the end of the pumping process described above.
Alternatively, if the volume of the pump 100 is not large enough, the above steps of sucking solvent in and pushing it into the buffer section 400 may be repeated until the buffer section 400 is completely filled with the solvent.
The filling up of the buffer section 400 may be followed by the pump 100 filling up solvent from the solvent reservoir 50 to be used in a subsequent flushing process. This may help increase the efficiency of the collection process and may be of interest when a plurality of closely spaced fractions may have to be collected. Additionally, the process of cleaning and filling up the buffer section 400 and filling up the pump 100 as described above may be repeated after collecting each fraction. This may also help to avoid contamination of any of the fractions with components from any other fraction.
As
In other words, the steps depicted in
The positioning of ports on the switching valve 200 such that the collection configuration of the switching valve 200 is between its discharge and buffer configurations may allow for rapid switching from the discharge configuration to the collection configuration by simply rotating the rotor of the switching valve by 45°. The pump 100 may not be operated while a fraction is being collected with the switching valve 200 in the collection configuration. This may involve, for example, no actuation of a piston of the pump 100 in case the pump 100 comprises a piston. The collection of the first fraction is continued until a second fraction that may be collected arrives at the detector 900.
The fluidic system 10 may now be switched to a buffer configuration. As regards an explanation for a function of the buffer configuration, reference may again be made to
Again with reference to
However, if directly switching the system to collect the sample in another collection reservoir (e.g., in the second collection reservoir 500b), one would also collect mixed sample constituents.
The above steps depicted in
E.g., to avoid this, the system 10 may be switched to the buffer configuration depicted in
Again, this is further depicted by illustration 1000′ in
The system can then be switched to the configuration depicted in
In other words, starting with the configuration depicted in
The switching valve 200 may be kept in its buffer configuration until all of the first fraction has been dispensed into the collection reservoir 500a. Once again, this time may have been determined with the aid of a peak duration for the first fraction and the time required for the peak to flow down to the collection needle 310, including the volume of the buffer section 400. Note also that some part of the second fraction may flow into the buffer section 400 until the first fraction has been completely dispensed into the collection reservoir 500a (see illustration 1000″ in
In other words, upon arrival of the second fraction the switching valve 200 switches to a buffer section configuration and continues collecting the first fraction via the buffer section 400. Namely, before the second target fraction flows into the collection tube 320, the switching valve 200 is switched to buffer configuration allowing the fluidic system 10 to keep pushing the remaining first target fraction inside the collection tube 320 and collection needle 310 through the pre-filled clean solvent inside the buffer section 400. The buffer section 400 is thus used to prevent mixing between the first and second target fractions. This configuration is maintained until all of the first target fraction is dispensed into the first collection reservoir 500a. At this time, the buffer section 400 may be almost filled up with the first fraction, the second fraction, and the solvent (mobile phase). The buffer configuration may help increase the recovery rate of the first target fraction. At the same time, the buffer section 400 may be used to prevent mixing between the first and second target fractions, thereby reducing carry over.
Once collection of the first fraction is complete, the switching valve 200 may be switched again, this time to its discharge configuration depicted in
The first connecting element 210b may now connect the ports 0 and 3, allowing some of the second fraction to flow into the waste reservoir 700. At the same time, the pump 100 may now be brought into fluidic connection with one port of the buffer section 400 while its other port may be connected to the waste reservoir 700. The buffer section 400 may now be cleaned of the mixture of solvent and first and second fraction that may be left over from the previous collection step by pushing the solvent stored in the pump 100. Clean solvent may flow into the buffer section 400 while the mixture of the first and second fraction and the solvent is pushed out into the waste reservoir 700. This may be achieved by actuation of a piston of the pump 100. Further, as
In other words, upon completion of collection of the first fraction through the buffer section 400 as described above, the switching valve 200 may switch to the discharge configuration with part of the second target fraction flowing into the waste reservoir 700. During this time, the pump 100 may be actuated to push the mixture of liquids inside the buffer section 400 into the waste reservoir 700 and refill it with clean solvent from the cavity of the pump 100. At the same time, the collection needle 310 may be moved to the next collection reservoir 500b. Then, the switching valve 200 may be switched back to the collection configuration to dispense the second fraction into the second collection reservoir 500b without any mixing and no carry over.
This may complete a circle of processes for fraction collection with the intermediate buffer configuration enabled.
Note that this is different from the process described above where partial collection of the first fraction was followed by switching the switching valve 200 to a buffer configuration which introduced the buffer section 400 into the flow path. This involved a rotation of the switching valve 200 by +90°. It may be more efficient instead to skip the buffer configuration and rotate the switching valve 200 only by −45° to bring it to the collection configuration (see
Thus, as depicted in
In other words, in the no buffer configuration, the pump 100 may be always held still. The fluidic system 10 triggers collection when the target fraction arrives. The switching valve 200 switches at a high speed over two configurations: the collection configuration (see
However, carrying out the collection process using these configurations may involve significant amounts of both the first and second fractions flowing into the waste reservoir 700. This is because the collection of the first fraction may have to be terminated earlier and the switching valve 200 switched from a collection configuration to a discharge configuration depicted in
Thus, the flow from port 0 may not be blocked and may not introduce a spike in back pressure. This may be facilitated in particular by, for example, choosing a length of the groove on the second port 2 (depicted in
It will be understood that the valve 200 described with reference to
Overall, embodiments of the present technology thus allow collection of fractions efficiently, with a high recovery rate and less or almost no carry-over, especially for closely placed fractions/peaks and very small volume fraction collection by employing a buffer configuration (flushing out or dispensing remaining liquid inside the collection tube 320 and the collection needle 310 to improve recovery rate and reduce carry-over).
Whenever a relative term, such as “about”, “substantially” or “approximately” is used in this specification, such a term should also be construed to also include the exact term. That is, e.g., “substantially straight” should be construed to also include “(exactly) straight”.
Whenever steps were recited in the above or also in the appended claims, it should be noted that the order in which the steps are recited in this text may be accidental. That is, unless otherwise specified or unless clear to the skilled person, the order in which steps are recited may be accidental. That is, when the present document states, e.g., that a method comprises steps (A) and (B), this does not necessarily mean that step (A) precedes step (B), but it is also possible that step (A) is performed (at least partly) simultaneously with step (B) or that step (B) precedes step (A). Furthermore, when a step (X) is said to precede another step (Z), this does not imply that there is no step between steps (X) and (Z). That is, step (X) preceding step (Z) encompasses the situation that step (X) is performed directly before step (Z), but also the situation that (X) is performed before one or more steps (Y1), . . . , followed by step (Z). Corresponding considerations apply when terms like “after” or “before” are used.
While in the above, preferred embodiments have been described with reference to the accompanying drawings, the skilled person will understand that these embodiments were provided for illustrative purpose only and should by no means be construed to limit the scope of the present invention, which is defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202111106132.9 | Sep 2021 | CN | national |
