Patent Application
20190111376
Chromatography involves the flowing of a mobile phase over a stationary phase to effect separation. To speed-up and enhance the efficiency of the separation, pressurized mobile phases are introduced. Carbon dioxide based chromatographic systems use CO2 as a component of the mobile phase flow stream, and the CO2 based mobile phase is delivered from pumps and carried through the separation column as a pressurized fluid. The CO2 based mobile phase is used to carry components of the analytes in a sample through the chromatography column to the detection system.
Chromatography systems often use a restrictor to interface to the detection system or to control system pressure. The restrictor can be used to maintain system pressure and introduce a portion of the mobile phase flow to the detection system.
A restrictor can provide a cost-effective method of controlling back pressure in a chromatography. However, the restrictor may be incapable of adapting to large changes in mobile phase composition, mobile phase flow rate, or post-column pressure. A pressure-controlling fluid interface may be used to compensate for changes in the mobile phase composition, but the pressure-controlling fluid may not able to adapt to changes in the mobile phase flow rate or post-separation column pressure. This inability to compensate can result in diminished performance and sensitivity of the chromatography system.
Example systems, methodologies, apparatus and kits herein provide for matching of the restrictor to separation column, and determining the mobile phase flow rate and post-column pressure that works optimally with this matched combination. As a result, the combination of matched separation column and restrictor can be implemented in a chromatography system and cause it to operate with optimal sensitivity.
For example, for a chromatography system that employs a pressure-controlling fluid interface, the example systems, methodologies, and apparatus herein provide for matching the separation column with the restrictor, and specifying the mobile phase flow rate and post-column pressure that optimizes performance of the chromatography system with this matched combination. Example kits are also provided that includes the matched restrictor and separation column, packaged together with at least one processing unit as a bundle, where the at least one processing unit is configured to execute processor-executable instructions to transmit an indication of the values of mobile phase flow rate and post-column pressure that optimizes performance of the chromatography system with this matched combination.
Example integrated microfluidic separation devices are also provided that are based on a separation columns matched with restrictors.
In one aspect, the present technology provides a method for configuring a chromatography system with independent control of system pressure and flow rate of a carbon dioxide-based mobile phase flow stream. This method includes determining a type of chromatography separation column to be used in the chromatography system; determining an operative value of a mobile phase flow rate of the CO2-based mobile phase flow stream that corresponds to the chromatography separation column; determining a matching restrictor to the type of chromatography separation column for use together during operation of the chromatography system, the matching restrictor being configured such that a post-column pressure in the chromatography system during operation is maintained at a target pressure at the operative value of the mobile phase flow rate; and bundling the chromatography separation column with its matching restrictor for distribution together as a single unit.
Embodiments of this aspect can include one or more of the following features. In certain embodiments, the target pressure is set to or above 1800 PSI. In some embodiments, the chromatography system includes a pressure-controlling interface. The pressure-controlling interface can interface to a low-pressure detector (e.g., MS detector, FID, etc.). In certain embodiments which include the pressure-controlling interface, the target pressure is set as the lowest initial pressure of the chromatography system. In certain embodiments, the method includes that the matching restrictor is configured such that a post-column pressure in the chromatography system during operation is a value above which the CO2-based mobile phase flow stream is in a relatively incompressible state (e.g., the density of the CO2 does not fluctuate greatly over small changes in temperature or pressure). The CO2-based mobile phase flow stream can include one or more modifiers or additives. In certain embodiments, in which a modifier is present, the matching restrictor provides an outlet pressure ranging from about 10% to about 20% lower than a target value of post-column pressure at a designated proportion of the modifier to the CO2-based mobile phase flow stream (e.g., about 30% when the modifier is methanol). In certain embodiments, the method includes that the matching restrictor is configured such that a post-column pressure in the chromatography system during operation is a value above which the CO2 and the modifier and/or additive components of the CO2-based mobile phase are completely miscible.
Another aspect of the technology is directed to a kit for a chromatography system with independent control of system pressure and flow rate of a CO2-based mobile phase flow stream. The kit includes: a chromatography separation column configured to be used in the chromatography system at an operative value of a mobile phase flow rate of the CO2-based mobile phase flow stream; a restrictor matched to the type of chromatography separation column for use together during operation of the chromatography system, the restrictor being configured such that a post-column pressure in the chromatography system during operation is maintained at a target pressure at the operative value of the mobile phase flow rate; and at least one processing unit configured to execute processor-executable instructions to transmit to a user, or to display to a display unit, data indicative of the operative value of the mobile phase flow rate of the CO2-based mobile phase flow stream that corresponds to the chromatography separation column and the target pressure.
Embodiments of this aspect of the technology can include one or more of the following features. In some embodiments, the processing unit is configured to execute processor-executable instructions to cause the chromatography system to maintain the post-column pressure at the target pressure during operation. In certain embodiments, the target pressure is set to above about 1800 PSI (e.g., 1900 PSI, 2000 PSI 2100 PSI). In certain embodiments, the restrictor is configured such that a post-column pressure in the chromatography system during operation is a value above which the CO2-based mobile phase flow stream is in a relatively incompressible state. In some embodiments, the processing unit is configured to execute processor-executable instructions to cause the post-column pressure in the chromatography system during operation is a value above which the CO2-based mobile phase flow stream is in a relatively incompressible state. In some embodiments, the processing unit is configured to execute instructions to cause the CO2-based mobile phase flow stream to flow at the specified value of the mobile phase flow stream. In some embodiments, the mobile phase includes one or more modifiers and/or one or more additives. In an embodiment which includes a methanol modifier, the restrictor can be configured to provide an outlet pressure ranging from about 10% to about 20% lower than a target value of a post-column pressure at a proportion of about 30% of the modifier to the CO2-based mobile phase flow stream. In other embodiments which include a modifier and/or additive, the restrictor can be configured such that a post-column pressure in the chromatography system during operation is a value above which the CO2 and the modifier and/or additive components of the CO2-based mobile phase are completely miscible. In some embodiments, the kits further include at least one memory to store the processor-executable instructions, wherein the at least one processing unit is communicatively coupled to the at least one memory.
In another aspect, the technology features an integrated microfluidic separation device. The device includes a chromatography system with independent control of system pressure and flow rate of a CO2-based mobile phase flow stream. The device further includes: a chromatography separation column; a restrictive element matched to the type of the chromatography separation column, the restrictor being configured such that a post-column pressure in the chromatography system during operation is maintained at a target pressure at the operative value of the mobile phase; and at least one processing unit configured to execute processor-executable instructions to transmit to a user, or display to a display unit, data indicative of the value of target pressure and a specified value of a mobile phase flow rate of the CO2-based mobile phase flow stream that corresponds to the chromatography separation column. In some embodiments, the device further includes at least one memory to store the processor-executable instructions, the memory being coupled to the processing unit. Certain embodiments also include an interface to a low-pressure detector. Embodiments can feature automated control and regulation. For example, in some embodiments, the device may include more than one restrictive element. In such embodiments, the device can determine the identify of each restrictive element and make the calculations for each restrictive element. Further, the device can include regulators that will automatedly set conditions such as flow rate and pressure, such that the target pressure can be maintained automatically without user involvement.
The above systems, methodologies, apparatus and kits provide numerous advantages. For example, by providing a matched combination of one or more restrictor, pressures and flow rates across one or more column dimensions in a SFC or other pressure-controlling fluid system leads to increased detector sensitivity over conventional systems. In addition to increased sensitivity, certain embodiments of the present technology provide the advantage of reduced setup time and elimination or minimization of optimization time for a column change or change in dimension of a column within a system. This is because, the column, restrictor, and flow rates are matched and pre-packaged, eliminating optimization steps. Further, some embodiments provide for increased usability as optimization steps after a column change can be eliminated.
It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.
One of ordinary skill in the art will understand that the drawings primarily are for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and/or structurally similar elements).
The features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings.
Following below are more detailed descriptions of various concepts related to, and embodiments of, methodologies, apparatus and systems for matching of the restrictor to separation column, and determining the mobile phase flow rate and post-column pressure that works optimally with this matched combination. It should be appreciated that various concepts introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the disclosed concepts are not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.
As used herein, the term “includes” means includes but is not limited to, the term “including” means including but not limited to. The term “based on” means based at least in part on.
A “restrictor” herein refers to a component used in a chromatography system that is used to restrict mobile phase flow and control system pressure. A restrictor may be used to interface to a detection component. Non-limiting examples of restrictors include a length of straight, small internal diameter tubing, a tapered restrictor, a converging-diverging restrictor, an integral restrictor, a fritted restrictor, or a thermally modulated variable restrictor.
Chromatography systems are widely used for separating a sample including analytes into its constituents. Due to their low cost and ease of manufacture, restrictors are implemented in many types of chromatography systems. The restrictor can be used to maintain system pressure in the chromatography system and to introduce a portion of the mobile phase flow to a detector. For example, the restrictor can be used to control the interface to a low-pressure detection component, such as but not limited to a mass spectrometry (MS) detection system, an evaporative light scattering detection system, or a flame ionization (FID) detection system.
Restrictors can fail through several different types of mechanisms. For example, a failure mechanism can result from a solid particle becoming lodged into the restrictor orifice, causing complete blockage. A failed restrictor according to this failure mechanism can be easy to diagnose. Since very little or no fluid would exit this failed restrictor, the detector response would be very low, or the chromatography system would exhibit very high or uncontrolled pressures. As another example, a second type of failure mode can result from increasing analyte or matrix deposits on the interior walls of the restrictor, causing a change in the restriction performance of the restrictor, but not a complete obstruction. Also, precipitated particles from the fluid may cause plugging of the restrictor. These modes may be more difficult to diagnose.
Replacement of a restrictor in a chromatography system can be a time-consuming process. For example, unless the replacement restrictor is matched to the separation column, a time-consuming calibration process may be required to optimize the performance of the chromatography system.
In an example chromatography system that includes a pressure-controlling fluid interface, a restrictor provides a simple, cost-effective method of providing back pressure. However, a fixed restrictor can be less capable of adapting to large changes in mobile phase composition, mobile phase flow rate, or post-column pressure. Use of a pressure-controlling fluid interface can compensate for changes in mobile phase composition, but the chromatography system may not be able to adapt to changes in mobile phase flow rate or post-column pressure.
Example systems, methodologies, apparatus and kits according to the principles herein can be used to match the restrictor of a chromatography system to the separation column, and specify the mobile phase flow rate and post-column pressure that works optimally with this matched restrictor-column combination. The resulting chromatography system, including the matched combination, operates with optimal sensitivity at the specified mobile phase flow rate and post-column pressure. The example systems, methodologies, and apparatus are applicable to an example chromatography system that employs a pressure-controlling fluid interface.
A chromatography system can exhibit poor sensitivity in detection if the target pressure differs greatly from the restrictor pressure. Therefore, a lengthy optimization process generally needs to be undertaken whenever a restrictor or separation column is changed. Example systems, methodologies, and apparatus according to the principles herein eliminate the need for a lengthy optimization process by providing kits including restrictor(s) matched to a separation column and package together with specifications for the optimal mobile phase flow rate for a chromatography system using the packaged components.
When operating a chromatography system with a pressure controlling fluid interface (including a supercritical fluid chromatography system), the performance is optimized if the restrictor is matched quite closely to a desired mobile phase flow rate and post-column pressure. Where these parameters are not well matched, detection sensitivity suffers greatly. Therefore, in order to ensure optimal sensitivity of the chromatography system, and to reduce the setup and optimization time by a user, the separation column, mobile phase flow rate, restrictor, and post-column pressure should be linked.
Non-limiting example systems, methodologies, and apparatus described herein can be used for configuring a chromatography system with independent control of system pressure and flow rate of a carbon dioxide (CO2)-based mobile phase flow stream.
According to block 102, the type of the chromatography separation column to be used in the chromatography system is determined. The type of chromatography column can be determined based on parameters such as its dimensions (internal diameter and length) and the packing material details such as particle diameter. As a non-limiting example, the separation column can be a conventional packed column having internal diameter (or other such cross sectional length) ranging from about 2.0 mm to about 4.6 mm, and a length ranging from about 0.03 m to about 0.25 m. As another non-limiting example, the separation column can be a microbore packed column, having an internal diameter ranging from about 0.5 mm to about 2.0 mm, and a length ranging from about 0.03 m to about 0.25 m. As yet another non-limiting example, the separation column can be a packed capillary column, having an internal diameter ranging from about 0.1 mm to about 0.5 mm, and a length ranging from about 0.05 m to about 0.5 m. The packed columns can contain packing media ranging from about 1.5 microns to about 10 microns. As yet another non-limiting example, the separation column can be an open tubular column, having an internal diameter ranging from about 0.025 mm to about 0.1 mm, and a length ranging from about 1.0 m to about 35 m. The volumetric pumping speeds and/or volumetric flow rates compatible with the detectors can affect the choice of column type (such as choosing but not limited to a microbore packed column). Packed capillary columns allow for lower volumetric flow rates, can be compatible with mass flow sensitive detectors, and allow for smaller elution peak. The choice of an open tubular column type can result in a compromise between efficiency and speed. Choice of the separation column provides for well-deactivated surfaces and stationary phases, uniform stationary phase films, and well-immobilized stationary phase films.
In block 104, an operative value of the mobile phase flow rate of the CO2-based mobile phase flow stream is determined that corresponds to the type of the chromatography separation column selected. In non-limiting examples, the operative value of the mobile phase flow rate can be determined as either a value of mobile phase flow rate that causes the chromatography system to stay below a maximum system pressure, or a value of mobile phase flow rate that maximizes the separation efficiency of the chromatography system.
According to block 106, the restrictor is matched to the type of chromatography separation column for use together during operation of the chromatography system. The matching restrictor is configured such that the post-column pressure in the chromatography system during operation is maintained at a target pressure at the operative value of the mobile phase flow rate. In a non-limiting example, the target pressure can be above about 1800 PSI.
According to the principles herein, the column dimensions can indicate the operative range of values of the mobile phase flow rate. The restrictor should be matched to the mobile phase flow rate such that the post-column pressure is set to a value above which the fluid is in its relatively incompressible state, such as but not limited to a value of target pressure above about 2000 PSI. Further, a target pressure of about 2000 PSIi can be sufficient to ensure good miscibility between the mobile phase and any liquid co-solvent (described as a secondary fluid hereinbelow). The restrictor can be matched to the operative value of the mobile phase flow rate such that it provides about 10% lower pressure than the target post-column pressure (such as but not limited to a value of about 1800 PSI) at about 30% modifier, a composition that can provide the highest pack pressure in a CO2-based mobile phase flow stream employing a methanol modifier. Setting the pressure at about 10% below the target pressure allows for a pressure-controlling fluid pump to bring the pressure up to a target pressure, while introducing a desirable amount of the pressure-controlling fluid. Any more or less of the pressure-controlling fluid flow can result in reduced sensitivity. In this manner, the matching restrictors, target pressures, and operative value of the mobile phase flow rates can be matched and packaged across each separation column dimension.
In an example chromatography system, the restrictor can be disposed on the downstream side of the separation column, to maintain the desired pressure conditions in the chromatographic column. The amount of restriction that a restrictor can provide can be determined by the ratio (aspect ratio) of the length to the internal diameter of the restrictor.
As a non-limiting example, the restrictor can be a fixed restrictor. Non-limiting example morphologies of restrictors include linear restrictors, tapered restrictors, converging-diverging restrictors, pinhole (integral) restrictors, and pinched restrictors. An example linear restrictor can be formed with a small internal diameter, such as but not limited to on the order of tens of microns. An example tapered restrictor has a drawn out portion at an end of the restrictor column. Restrictor types such as the converging-diverging restrictor, pinhole (integral) restrictor, and pinched restrictor present small orifices. In any example herein, the restrictor can be formed from fused silica tubing.
In any example of
In a non-limiting example of
In any example of
The mobile phase flow stream can employ a single fluid or a be a mixed mobile phase. In an example, the mobile phase fluid is CO2-based mobile phase, due to its low critical temperature, relative inertness, low toxicity, and non-flammability. In other examples, the mobile phase fluid can include CO, N2O, ammonia, sulfur dioxide, or freon. In an example, the mobile phase can be a mixed mobile phase, such as but not limited to a mobile phase that includes an added proportion of a secondary fluid. Non-limiting examples of a secondary fluid include a modifier (such as but not limited to a polar organic modifier), a ternary additive, or other material. For example, the CO2-based mobile phase flow stream can further includes a modifier, a ternary additive, or a combination of one or more modifiers and one or more ternary additives.
The proportion of an added secondary fluid can be considered in determining the matching restrictor. For example, the matching restrictor can be configured such that a post-column pressure in the chromatography system during operation is a value above which the CO2-based mobile phase flow stream is in a relatively incompressible state. In a non-limiting example, the CO2-based mobile phase flow stream provides for a specified threshold CO2-modifier miscibility. The specified threshold miscibility can be a value that indicates good CO2-modifier miscibility. For example, in a binary phase diagram (two fluids), there exists a region defined by temperatures and pressures where the two fluids are immiscible. This boundary changes with the mass fraction between the two fluids, and can be encountered in chromatography at low pressures and high temperature. As a non-limiting example, for 10% methanol in a CO2-based mobile phase, the two fluids are immiscible at a pressure of about 1500 PSIi and a temperature of about 60° C. The specified threshold CO2-modifier miscibility can be achieved in regions of the binary phase diagram outside this boundary (such as but not limited to by increasing the pressure). For example, for the miscibility of the 10% methanol in the CO2-based mobile phase can be restored by increasing the pressure.
In another non-limiting example, where the CO2-based mobile phase flow stream includes a methanol modifier, the matching restrictor can be chosen to provide an outlet pressure ranging from about 10% to about 20% lower than a target value of a post-column pressure at a proportion of about 30% of the modifier to the CO2-based mobile phase flow stream.
In a further non-limiting example, where the CO2-based mobile phase flow stream includes modifier and/or one or more additives, the matching restrictor is configured such that a post-column pressure in the chromatography system during operation is a value above which the CO2 and the modifier and/or additive components of the CO2-based mobile phase are completely miscible.
The example chromatography system includes a chromatography separation column configured to be used in the chromatography system at an operative value of a mobile phase flow rate of the CO2-based mobile phase flow stream, and a restrictor matched to the type of chromatography separation column for use together during operation of the chromatography system. The restrictor is configured such that the post-column pressure in the chromatography system during operation is maintained at a target pressure at the operative value of the mobile phase flow rate.
The apparatus 200 includes at least one memory 202 and at least one processing unit 204. The at least one processing unit 204 is communicatively coupled to the at least one memory 202 and also to at least one component of a chromatography system 206.
The at least one memory 202 is configured to store processor-executable instructions 208 and a computation module 210. In an example method as described in connection with
Example systems, methodologies, and apparatus according to the principles herein can provide kits that can used to optimize the sensitivity of a chromatography system. An example kit includes a chromatography separation column configured to be used in the chromatography system at an operative value of a mobile phase flow rate of the CO2-based mobile phase flow stream, and a restrictor matched to the type of chromatography separation column for use together during operation of the chromatography system. The restrictor is configured such that the post-column pressure in the chromatography system during operation is maintained at a target pressure at the operative value of the mobile phase flow rate. The example kit also includes at least one processing unit that is configured to communicate with at least one component of a chromatography system. The example processing unit can include processor-executable instructions execute processor-executable instructions to transmit to a user, or to display to a display unit, data indicative of the operative value of the mobile phase flow rate of the CO2-based mobile phase flow stream that corresponds to the chromatography separation column and the target pressure.
An example kit can include, in a bundled package, a separation column, a restrictor matched to the type of the separation column according to the principles described herein, and at least one processing device configured to execute processor-executable instructions to transmit an indication of the values of mobile phase flow rate and post-column pressure that optimizes performance of the chromatography system with this matched combination of restrictor and separation column.
An example kit according to the principles herein can be configured based on a select combination of at least four components—a separation column, at least one restrictor, pressure-controlling pump, and at least one processing device. The example kit is in a bundled package is suitable for a chromatography system configured to operate with a pressure-controlling fluid interface. Each of the at least one restrictor is matched to the type of the separation column according to the principles described herein. The type of the separation column determines the appropriate value of mobile phase flow rate, and the value of the flow rate in turn determines the type of the at least one restrictor that is matched to the separation column. The percentage (%) reduction in restrictor pressure versus a target system pressure is present to allow for the pressure-controlling fluid flow rate to span the difference between the restrictor pressure and the target system pressure. The pressure-controlling fluid pump uses a control loop to deliver the appropriate fluid flow rate through the restrictor such that the chromatography system remains at the target system pressure, i.e., the pressure-controlling fluid pump operates in a constant-pressure mode.
In an example kit, the processing unit can further execute processor-executable instructions to cause the chromatography system to maintain the post-column pressure at the target pressure during operation.
In an example kit where the restrictor is configured such that a post-column pressure in the chromatography system during operation is a value above which the CO2-based mobile phase flow stream is in a relatively incompressible state, the at least one processing unit can be further configured to execute processor-executable instructions to cause the post-column pressure in the chromatography system during operation to be at a value above which the CO2-based mobile phase flow stream is in a relatively incompressible state.
In some embodiments, the target pressure post-column is designed to be held constant over a composition gradient. In certain embodiments, the matching restrictor is designed to allow pressure to be modulated to maintain constant average pressure on the column over a composition gradient. In certain embodiments, the system is designed to execute a pressure-programmed gradient separation with a neat CO2 mobile phase.
At least one processing unit of the example kit can be programmed further to execute processor-executable instructions to cause the CO2-based mobile phase flow stream to flow at the specified value of the mobile phase flow rate.
In an example, the example kit further includes at least one memory to store the processor-executable instructions, where the at least one processing unit is communicatively coupled to the at least one memory.
An example kit also can include an apparatus 200 as shown in
The data for the operative value of the mobile phase flow rate and/or the target pressure can be computed based on measurement data from the desired performance range of a set of chromatography systems that include known restrictor components, known separation columns, for known values of mobile phase flow rate and mixed mobile phase composition set to known values. Measurement data indicative of the performance of the chromatography systems can be collected for each run of a chromatography system that includes each of the series of restrictor components and separation columns at the known conditions. As an example, the chromatography system can include one or more sensors to measure the flow rate and/or pressure to provide the measurement data used for computing the operative value of the mobile phase flow rate and/or the target pressure.
The example systems, methodologies, and apparatus, including the kits, described herein are applicable to many different types of chromatography systems that include at least one restrictor component. While the example systems, methodologies, apparatus and kits are described herein relative to certain types and configurations of chromatography systems, they apply to many different types of chromatography systems, such as but not limited to supercritical fluid chromatography (SFC) systems (including but not limited to UltraPerformance Convergence Chromatography™ (UPC2™) chromatography systems available from Waters Corporation, Milford, Mass.), high performance liquid chromatography (HPLC) systems, ultra-high performance liquid chromatography (UHPLC), gas chromatography (GC) systems, dense GC systems, solvating GC separation systems, and supercritical fluid extraction (SFE) systems.
The sample injector 303 is in fluidic communication with a sample source from which the sample injector 303 acquires a sample (i.e., the material under analysis) and introduces the sample to the mobile phase arriving from the solvent delivery system 301. Non-limiting examples of samples include complex mixtures of proteins, protein precursors, protein fragments, reaction products, small molecules and other compounds.
The chromatography column 307 is adapted to separate the various components (or analytes) of the sample from each other at different rates as the mobile phase passes through, and to elute the analytes (still carried by the mobile phase) from the chromatography column 307 at different times. Non-limiting examples of the chromatography column 307 include a variety of sizes (e.g., preparative, semi-preparative, analytical-scale (e.g., 4.6 mm ID), or capillary-scale packed-bed columns or open tubular columns) and a variety of preparations, such as but not limited to is metallic, fused silica, or polymeric tubes, or in metallic, ceramic, silica, glass, or polymeric microfluidic platforms or substrates of various internal dimensions. Packed columns contain packing media of various diameter, porosity, and functionality.
As shown in
In examples, data, and/or commands for control, and/or instructions can be communicated between the computing device 313 and at least one component of the chromatography system. For example, the computing device 313 can be used to execute processor-executable instructions to control the pressure, and/or temperature, and/or mobile phase flow rate, and/or mobile phase composition in one or more components of the chromatography system, based on the operative value of the mobile phase flow rate and/or the target pressure for the known separation column and matching restrictor component. As another example, the computing device 313 can be used to execute processor-executable instructions to run a density program by which the computing device 313 controls the system pressure produced by the solvent delivery system 301 during the course of the chromatographic run, or run a gradient schedule by which the computing system 313 controls the mobile phase composition produced by the solvent delivery system 301. As yet another example, the computing device 313 can be used to execute processor-executable instructions to control the temperature of a component of the chromatography system, such as but not limited to the column oven 307 and/or the restrictor 309.
The example detector 311 can be a gas chromatography type detector, such as but not limited to a flame ionization detector (FID) and a mass spectrometer. Other example detectors 311 include, but are not limited to, a mass spectrometer and an evaporative light scattering detector. The output of the detector 311 depends on the type of detector, and can be, for example, a voltage signal or a current that is applied, for example, to an X-Y plotter or some type of chart recorder, which graphs the detector output over time, or is supplied as input to a data system, such as included in computing device 313. Other types of detectors can be used in connection with the restrictors described herein.
The computing device 313 including the at least one processing unit 204 can be used to execute the example processes and computations described herein. The computing device 313 can include at least one apparatus 10 described hereinabove. An example kit as described herein that includes a restrictor and the at least one processing unit may be coupled with the example chromatography system to provide the system shown in
As shown in
In any of the example systems, methodologies, apparatus or kits herein, the at least one processing unit 204 is communicatively coupled to the at least one memory 202 and also to at least one component of a chromatography system (including chromatography system 206), to transmit and/or receive measurement data (such as but not limited to flow rate data, pressure data, and/or temperature data), perform database queries, and implement any other processes described herein, including the processes described in connection with any one or more of
In any of
Example systems, methodologies, and apparatus according to the principles herein also provide an integrated microfluidic separation device. The example integrated microfluidic separation device includes a chromatography system with independent control of system pressure and flow rate of a CO2-based mobile phase flow stream and a chromatography system. The example chromatography system includes a chromatography separation column, and a restrictive element matched to the type of the chromatography separation column. The restrictor is configured such that a post-column pressure in the chromatography system during operation is a value of target pressure above which the CO2-based mobile phase flow stream is in a relatively incompressible state. The example integrated microfluidic separation device also includes at least one processing unit configured to execute processor-executable instructions to transmit to a user, or display to a display unit, data indicative of the value of target pressure and a specified value of a mobile phase flow rate of the CO2-based mobile phase flow stream that corresponds to the chromatography separation column.
In an example, the integrated microfluidic separation device further includes at least one memory to store the processor-executable instructions, where the at least one processing unit is communicatively coupled to the at least one memory.
In an example, the integrated microfluidic separation device further includes an inlet port for a pressure-controlling fluid.
Formed within the layers of the example microfluidic substrate 400 is a serpentine fluidic channel 402 for transporting the mobile phase. The fluidic channel 402 can be, for example, lasered, etched, embossed, or machined into the substrate layers. The fluidic channel 402 passes through two regions of the microfluidic substrate 400, including a column region 404 and a restrictor body region 406. The column region 404 can include a trap region 408. Apertures 412-1 and 412-2 open into the fluidic channel 402 at opposite ends of the trap region 408. The fluidic aperture 412-2 at the “downstream” end of the trap region 408 is optionally used as a fluidic outlet aperture, for example, during loading of the trap region 408, and is optionally closed to fluid flow, for example, during injection of a loaded sample from the trap region 408 into the fluidic channel 402.
The fluidic channel 402 terminates at an opening 410 in an edge of the microfluidic substrate 400. A restrictor tip, such as any of the matching restrictors described herein (including in connection with any of
Alternatively, the fluidic channel 402 can terminate at an opening in a side of the substrate 400. Other types of restrictor tips can be integral to the microfluidic substrate, for example, a frit can be embedded into the microfluidic substrate at the egress end of the fluidic channel 402, or the opening 410 can be fashioned to be smaller than the ID of the fluidic channel 402. In contrast to the externally attached restrictor tips, the integral restrictors cannot be removed and replaced. The sizes of the regions 404, 406, 408, and the shape and length of the fluidic channel 402 within each region, are merely illustrative examples. Other examples of microfluidic platforms 400 can have the restrictor body region 406 and column region 404 on different interconnected tiles, similar to that illustrated in the aforementioned International application no. PCT/US2010/026342.
The restrictor body and column regions 404, 406, whether implemented on the same or on different substrates, can be independently controlled thermal regions.
The pressure-controlling fluid can be introduced after the column region 404 and upstream of the restrictive element 402.
Non-limiting examples of variations of chromatography systems that can be implemented using the separation column and include at least one matching restrictor, and operated at the operative value of the mobile phase flow rate and/or the target pressure according to the principles herein, are described in connection with the non-limiting examples of
One or more sensors can be disposed at various points in the mobile phase streams, e.g., downstream of the chromatography column 615. For example, a sensor disposed between the chromatography column 615 and the tee fitting 618 can be a pressure transducer that measures the system pressure before the stream of mobile phase is split. Alternatively, a sensor such as a viscometer or densitometer can be configured to measure the composition of the mobile phase. Such measurements can be used to detect changes in the chromatographic run, for example, those pressure changes corresponding to a density program or mobile phase composition changes corresponding to a composition gradient. As another example, a first sensor may be disposed in the main mobile phase flow between the tee fitting 618 and the pressure-controlling component 621 to measure the total mass flow rate, and a second sensor may be disposed in the minority mobile phase stream between the restrictor 619 and the detector 623 to measure the mass flow rate of the minority portion. The split ratio can be determined from the ratio of these flow rates.
The example of
The example systems, methodologies, apparatus and kits described herein can be used in a chromatography system that includes two pressure-controlling components. In such as example, employing an additional (secondary) pressure regulation device or pressure control element in a CO2-based chromatography system allows for efficient full-flow introduction of the mobile phase stream to a low-pressure detector when using a back pressure regulator. The secondary pressure control device ensures mobile phase density all the way into the detector, thereby preventing phase separation and analyte precipitation, which may occur without a secondary pressure control device.
In some examples, the secondary pressure control device 723 is located as close as possible to the point of detection inside the detector 725. In a non-limiting example, the point of detection is the flame inside a FID or the electrospray ionization spray plume inside a mass spectrometer (MS). In one embodiment, the outlet of the secondary pressure control element 727 can be located within about 5.0 cm from the inlet of the detector 723. In some embodiments, the outlet 727 of the secondary pressure control element 723 is located within about 2.5 cm from the inlet of the detector 725. In certain embodiments the outlet 727 is within 1 cm or less of the inlet to detector 725. The secondary pressure control element 723 can be, for example, a restrictor, a back pressure regulator, or a variable restrictor (such as but not limited to a thermally modulated variable restrictor). This example shows a secondary pressure control device 723 incorporated into a full-flow CO2-based chromatography system. The secondary pressure control device 723 provides for increased CO2/co-solvent miscibility and improved analyte transport from the primary pressure control element 719 to the detector 723. The secondary pressure control device 723 addresses the limitations encountered with interfacing CO2-based chromatography to detection and helps prevent phase separation while transporting the analyte from the primary pressure control device 719 to the detector 723.
In a non-limiting example, both the primary pressure control element 719 and the secondary pressure control element 723 can be BPRs.
In exemplary embodiments, the user electronic device 803 may include a display unit 810, which can display a GUI 802 to a user of the device 803 such that the user can view the rendered graphic icon, visual display, or type of other signal used to indicate the operative value of a mobile phase flow rate and/or target pressure for a matching restrictor, as described above. The user electronic device 803 may include, but is not limited to, smart phones, tablets, ultrabooks, netbooks, laptops, computers, general purpose computers, Internet appliances, hand-held devices, wireless devices, portable devices, wearable computers, cellular or mobile phones, portable digital assistants (PDAs), desktops, multi-processor systems, microprocessor-based or programmable consumer electronics, game consoles, set-top boxes, network PCs, mini-computers, smartphones, tablets, netbooks, and the like. The user electronic device 803 may include some or all components described in relation to computing device 900 shown in
In exemplary embodiments, the user can interact with the user electronic device 803 using a keyboard, mouse, gamepad controller, voice commands, or non-touch gestures recognizable by the user electronic device. In alternative embodiments, the user electronic device 803 can be a mobile device, such as a smartphone, or tablet.
In exemplary embodiments, the user electronic device 803, analytics engine 807, and database 815 may be in communication with each other via a communication network 801. The communication network 801 may include, but is not limited to, the Internet, an intranet, a LAN (Local Area Network), a WAN (Wide Area Network), a MAN (Metropolitan Area Network), a wireless network, an optical network, and the like. In one embodiment, the user electronic device 803, and analytics engine 807 can transmit instructions to each other over the communication network 801. In exemplary embodiments, the flow rate measurement data, pressure measurement data, and other data (including temperature data) can be stored at database 815 and received at the analytics engine 807.
In general, system 800 can identify the column/restrictor package installed and automatically set the appropriate mobile phase flow rate and its target pressure (i.e., uses NFC, RFID, barcode, pins, resistor values, or any other mechanical/electrical devices).
For example, memory 906 included in the computing device 900 can store computer-readable and computer-executable instructions or software for implementing exemplary embodiments and programmed to perform processes described above in reference to any one or more of
Virtualization can be employed in the computing device 900 so that infrastructure and resources in the computing device can be shared dynamically. A virtual machine 914 can be provided to handle a process running on multiple processors so that the process appears to be using only one computing resource rather than multiple computing resources. Multiple virtual machines can also be used with one processor.
Memory 906 can be non-transitory computer-readable media including a computer system memory or random access memory, such as DRAM, SRAM, EDO RAM, and the like. Memory 906 can include other types of memory as well, or combinations thereof.
A user can interact with the computing device 900 through a visual display device 903, such as a touch screen display or computer monitor, which can display one or more user interfaces 802 that can be provided in accordance with exemplary embodiments. The computing device 900 can also include other I/O devices for receiving input from a user, for example, a keyboard or any suitable multi-point touch interface 908, a pointing device 910 (e.g., a pen, stylus, mouse, or trackpad). The keyboard 908 and the pointing device 910 can be coupled to the visual display device 903. The computing device 900 can include other suitable conventional I/O peripherals.
The computing device 900 can also include one or more storage devices 924, such as a hard-drive, CD-ROM, or other non-transitory computer readable media, for storing data and computer-readable instructions and/or software, such as a data computation module 809 that can implement exemplary embodiments of the methodologies and systems as taught herein, or portions thereof. Exemplary storage device 924 can also store one or more databases 815 for storing any suitable information required to implement exemplary embodiments. The databases can be updated by a user or automatically at any suitable time to add, delete, or update one or more items in the databases. Exemplary storage device 924 can store one or more databases 815 for storing flow rate measurement data, pressure measurement data, and any other data/information used to implement exemplary embodiments of the systems and methodologies described herein.
The computing device 900 can include a network interface 912 configured to interface via one or more network devices 922 with one or more networks, for example, Local Area Network (LAN), Wide Area Network (WAN) or the Internet through a variety of connections including, but not limited to, standard telephone lines, LAN or WAN links (for example, 802.11, T1, T3, 56 kb, X.25), broadband connections (for example, ISDN, Frame Relay, ATM), wireless connections, controller area network (CAN), or some combination of any or all of the above. The network interface 912 can include a built-in network adapter, network interface card, PCMCIA network card, card bus network adapter, wireless network adapter, USB network adapter, modem or any other device suitable for interfacing the computing device 900 to any type of network capable of communication and performing the operations described herein. Moreover, the computing device 900 can be any computer system, such as a workstation, desktop computer, server, laptop, handheld computer, tablet computer (e.g., the iPad® tablet computer), mobile computing or communication device (e.g., the iPhone® communication device), or other form of computing or telecommunications device that is capable of communication and that has sufficient processor power and memory capacity to perform the operations described herein.
The computing device 900 can run any operating system 916, such as any of the versions of the Microsoft® Windows® operating systems, the different releases of the Unix and Linux operating systems, any version of the MacOS® for Macintosh computers, any embedded operating system, any real-time operating system, any open source operating system, any proprietary operating system, any operating systems for mobile computing devices, or any other operating system capable of running on the computing device and performing the operations described herein. In exemplary embodiments, the operating system 916 can be run in native mode or emulated mode. In an exemplary embodiment, the operating system 916 can be run on one or more cloud machine instances.
In describing example embodiments, specific terminology is used for the sake of clarity. For purposes of description, each specific term is intended to at least include all technical and functional equivalents that operate in a similar manner to accomplish a similar purpose. Additionally, in some instances where a particular example embodiment includes a plurality of system elements, device components or method steps, those elements, components or steps can be replaced with a single element, component or step. Likewise, a single element, component or step can be replaced with a plurality of elements, components or steps that serve the same purpose. Moreover, while example embodiments have been shown and described with references to particular embodiments thereof, those of ordinary skill in the art will understand that various substitutions and alterations in form and detail can be made therein without departing from the scope of the disclosure. Further still, other aspects, functions and advantages are also within the scope of the disclosure.
Example flowcharts are provided herein for illustrative purposes and are non-limiting examples of methodologies. One of ordinary skill in the art will recognize that example methodologies can include more or fewer steps than those illustrated in the example flowcharts, and that the steps in the example flowcharts can be performed in a different order than the order shown in the illustrative flowcharts.
In alternative embodiments, the techniques described above with respect to pumps used in CO2-based chromatography systems may be applicable to pumps used in other types of chromatography systems that include mobile phases that vary greatly in density with minor changes in temperature (and/or pressure). For example, a mobile phase including methanol at extremely high pressures may in some instances benefit from added temperature control. In describing certain example, specific terminology is used for the sake of clarity. For purposes of description, each specific term is intended to at least include all technical and functional equivalents that operate in a similar manner to accomplish a similar purpose. Additionally, in some instances where a particular example embodiment includes a plurality of system elements, device components or method steps, those elements, components or steps may be replaced with a single element, component or step. Likewise, a single element, component or step may be replaced with a plurality of elements, components or steps that serve the same purpose. Moreover, while example embodiments have been shown and described with references to particular embodiments thereof, those of ordinary skill in the art will understand that various substitutions and alterations in form and detail may be made therein without departing from the scope of the invention. Further still, other aspects, functions and advantages are also within the scope of the disclosure.
While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be examples and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that inventive embodiments may be practiced otherwise than as specifically described. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methodologies, if such features, systems, articles, materials, kits, and/or methodologies are not mutually inconsistent, is included within the inventive scope of the present disclosure.
Also, the technology described herein may be embodied as a method, of which at least one example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”
As used herein in the specification, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.
This application claims priority to U.S. Provisional Application No. 62/571,539, filed on Oct. 12, 2017, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62571539 | Oct 2017 | US |
