Single unit device for viscosity and light scattering, and method therefor

Abstract

A single unit device for viscosity and light scattering, and a method therefor are disclosed. The single unit device can include an inlet line, a first fluid flow line and a second fluid flow line in fluid communication with the inlet line, a light scattering detector (LSD), a pressure transducer line, a pressure transducer disposed in and fluid-coupled to the pressure transducer line, and an outlet stream. The first fluid flow line can include a first capillary and a second capillary, and a first T-connector inserted between the first capillary and the second capillary. The second fluid flow line can include a first capillary and a second capillary, and a second T-connector inserted between the first capillary and the second capillary. The LSD can be disposed downstream of the second T-connector and upstream of the second capillary of the second fluid flow line. The outlet stream can be in fluid communication with the second capillary of each of the first fluid flow line and the second fluid flow line.

Description

Technical Field

[0001] The present invention relates to a single unit device for viscosity and light scattering, and a method therefor. (Cross-reference to related applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 358,348, filed on July 5, 2022, the content of which is incorporated herein by reference to the extent not inconsistent with the present disclosure.

Background Art

[0002] In liquid chromatography such as size exclusion chromatography, the experimental throughput is often determined or limited by the rate of sample preparation and separation rather than by the detection time. For this reason, it is common to install multiple detectors after the sample preparation and separation processes to efficiently and simultaneously obtain more characteristic information from a single chromatography run. General detectors for concentration measurement and species identification may include detectors for refractive index, ultraviolet absorption, infrared absorption, etc. General detectors for measuring the microstructure of polymers may include viscosity detectors and light scattering detectors, etc., which generally also require a paired concentration detector for reference at each chromatography data point. These detectors can be arranged in series or in parallel with each other. Since the hydrodynamics of liquid chromatography are maintained under laminar flow, the respective signals for each successive detector are spread along a line or flow path (e.g., a tube) arranged upstream, or according to the detector. The relative signal time also needs to be adjusted due to the fluid delay between the detectors. A method using mathematical correction (e.g., via an algorithm) is often required to address the phenomena of signal spreading and fluid delay between the detectors.

[0003] These mathematical corrections are well established in the field of liquid chromatography, but it is also well known that these mathematical corrections can lead to a problematic decrease in chromatographic resolution. For example, mathematical corrections can often include convolution and offset of upstream detectors to match the broadest and subsequent or latest elution detectors, which leads to a decrease in chromatographic resolution. Conversely, deconvolution of detectors in the field of liquid chromatography is not recommended or taught due to amplification of noise in conventional deconvolution processes.

[0004] In addition to the above, it should be understood that arranging detectors in series or a series configuration has the drawback that the additional detector spreads from the downstream or subsequent detector. Utilizing a series configuration can also make it difficult to cause excessive backpressure in the upstream detector. Furthermore, some detectors, such as viscometers, can dilute the sample concentration, and some detectors, such as conventional refractometers, can have relatively large waste lines that can worsen spreading. Arranging detectors in parallel or a parallel configuration has the drawback of causing further spreading over time due to the reduction in flow rate in the parallel configuration. Furthermore, the flow through the parallel lines can change over time because there is a defect (e.g., an adhesion) in one of the lines. The parallel configuration also often requires combining the respective waste lines of each detector to avoid gravity effects. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] Therefore, what is needed is an improved detector for viscosity and light scattering to address the aforementioned technical problems. MEANS FOR SOLVING THE PROBLEM

[0006] This summary is intended to introduce, in a simplified form, some aspects of one or more embodiments of the present disclosure. Further applicable areas of the present disclosure will become apparent from the detailed description provided below. This summary is not intended to provide an extensive overview nor to identify key or critical elements of the present teachings or to delineate the scope of the present disclosure. Instead, its purpose is merely to present, in a simplified form, one or more concepts as a prelude to the detailed description that follows.

[0007] The foregoing and / or other aspects and facilities embodied in the present disclosure can be achieved by providing a single unit device. The single unit device may include an inlet line, a first fluid flow line, a second fluid flow line, a light scattering detector, a pressure transducer line, a pressure transducer, and / or an outlet stream. The first fluid flow line may include a first capillary in direct fluid communication with the inlet line, a second capillary disposed in series with the first capillary, and a first T-connector inserted between the first and second capillaries of the first fluid flow line. The second fluid flow can be in fluid communication with the inlet. The second fluid flow line may include a first capillary in direct fluid communication with the inlet line, a second capillary disposed downstream of the first capillary, and a second T-connector inserted between the first and second capillaries of the second fluid flow line. The light scattering detector may be disposed downstream of the second T-connector and upstream of the second capillary of the second fluid flow line. The pressure transducer line may fluidly couple the first T-connector to the second T-connector. The pressure transducer may be disposed within and fluidly coupled to the pressure transducer line. The outlet stream may be in fluid communication with the second capillary of the first fluid flow line and the second capillary of the second fluid flow line.

[0008] In at least one embodiment, the single unit device may further include a dilution reservoir disposed downstream of the light scattering detector and upstream of the second capillary of the second fluid flow line.

[0009] In at least one embodiment, the light scattering detector may include a sample cell, the sample cell being fluidly coupled to a first capillary of a second fluid flow line and disposed downstream of the first capillary of the second fluid flow line, and may include an inlet and first and second outlets fluidly coupled to a second capillary of the second fluid flow line and disposed upstream of the second capillary of the second fluid flow line.

[0010] In at least one embodiment, the sample cell may further include a body, the body defining a flow path extending axially therethrough, the flow path may include a cylindrical inner section inserted between a first outer section and a second outer section, the first outer section being frustoconical, a first end of the first outer section being in direct fluid communication with the inner section and having a cross-sectional area relatively smaller than a cross-sectional area at a second end of the first outer section, the body being in direct fluid communication with the inner section and further defining an inlet configured to direct a sample toward the inner section of the flow path, the body further defining first and second outlets, the first and second outlets being configured to fluidly couple the first and second outer sections to an outlet stream via a second capillary of the second fluid flow line.

[0011] In at least one embodiment, the second outer section of the sample cell may be frustoconical, a first end of the second outer section being in direct fluid communication with the inner section and having a cross-sectional area relatively smaller than a cross-sectional area at a second end of the second outer section.

[0012] In at least one embodiment, the body may define a first recess extending axially therethrough, the first recess being in fluid communication with the first outer section and being configured to receive a first lens of the light scattering detector.

[0013] In at least one embodiment, the body may define a second recess extending axially through the body, the second recess may be in fluid communication with the second outer section, and may be configured to receive a second lens of the light scattering detector.

[0014] In at least one embodiment, the body of the sample cell may define an aperture extending radially through the body, and the aperture may be in direct fluid communication with the inner section of the flow path.

[0015] In at least one embodiment, the single unit device may further include an optically transparent material disposed within the aperture.

[0016] In at least one embodiment, the single unit device may be fluidly coupled to a pressure transducer and may further include one or more purge lines configured to purge the pressure transducer.

[0017] In at least one embodiment, the single unit device may further include respective purge valves disposed in each of the one or more purge lines, and optionally, each of the one or more purge lines may be fluidly coupled to an outlet stream.

[0018] In at least one embodiment, the light scattering detector may further include a laser for emitting a light beam, and the flow path of the sample cell may have a centerline aligned with the light beam.

[0019] In at least one embodiment, the light scattering detector may be operably coupled to the sample cell and may further include at least one detector configured to receive scattered light emitted from the sample cell.

[0020] The foregoing and / or other aspects and utilities embodied in the present disclosure can be achieved by providing a system including a single unit device disclosed according to any of this specification or the preceding paragraphs, and a refractometer operably coupled to the single unit device.

[0021] In at least one embodiment, the single unit device and the refractometer can be operably coupled in series with each other.

[0022] In at least one embodiment, the refractometer can be disposed upstream of the single unit device.

[0023] The foregoing and / or other aspects and facilities embodied in the present disclosure can be achieved by providing a method of using any one of the systems disclosed herein, which can include a single unit device and a refractometer operably coupled to the single unit device. The method can include flowing a sample through the refractometer and flowing the sample through the single unit device.

[0024] In at least one embodiment, flowing a sample through the single unit device can include flowing the sample from an inlet line to an outlet stream via a first fluid flow line and a second fluid flow line.

[0025] In at least one embodiment, flowing a sample through the second fluid flow line can include flowing the sample through a first capillary and a second capillary of the second fluid flow line and flowing the sample through a light scattering detector inserted between the first capillary and the second capillary of the second fluid flow line.

[0026] In at least one embodiment, the method can further include flowing the sample from the refractometer to the single unit device.

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the present disclosure. These and / or other aspects and advantages of the present disclosure will become apparent from the following description of various embodiments taken in conjunction with the accompanying drawings and will be more readily understood. It should be noted that some details of the drawings are simplified and are drawn not to maintain exact structural accuracy, details, and scale, but to facilitate the understanding of the present disclosure. These drawings / figures are intended to be illustrative and not restrictive.

Brief Description of the Drawings

[0028]

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DETAILED DESCRIPTION OF THE INVENTION

[0029] The following description of various exemplary aspects is, in essence, merely illustrative and is not intended to limit the present disclosure, its application, or its use in any way.

[0030] Throughout this disclosure, each range is used as an abbreviation for describing each and every value within that range. It should be recognized and understood that the description of a range in this form is for convenience and brevity only and should not be construed as an immutable limitation on the scope of any embodiment or aspect disclosed herein. Thus, the disclosed ranges should be construed as specifically disclosing all possible sub-ranges, as well as the individual numerical values within that range. As such, any value within the range can be selected as an end point of the range. For example, a description of a range such as 1 - 5 is to be considered as specifically disclosing sub-ranges such as 1.5 - 3, 1 - 4.5, 2 - 5, 3.1 - 5, etc., as well as the individual numbers within that range, such as 1, 2, 3, 3.2, 4, 5, etc. This applies regardless of the breadth of the range.

[0031] In addition, all numerical values are values indicated by "about" or "approximately", taking into account experimental errors and variations expected by those skilled in the art. It should be understood that all numerical values and ranges disclosed herein are approximate values and ranges, whether or not "about" is used in combination therewith. Also, as used herein, the term "about" in conjunction with a numerical value means a value that can be ±0.01% (inclusive), ±0.1% (inclusive), ±0.5% (inclusive), ±1% (inclusive), ±2% (inclusive) of that numerical value, ±3% (inclusive) of that numerical value, ±5% (inclusive) of that numerical value, ±10% (inclusive) of that numerical value, or ±15% (inclusive) of that numerical value. It should further be understood that when a numerical range is disclosed herein, any numerical value falling within the range is also specifically disclosed.

[0032] All references cited herein are hereby incorporated by reference in their entirety. In case of conflict between the definitions of the present disclosure and those of the cited references, the present disclosure shall control.

[0033] FIG. 1 shows a schematic diagram of a conventional viscometer 100 according to the prior art. The conventional viscometer 100 shown in FIG. 1 may also be referred to as a Wheatstone bridge viscometer 100, which is described in more detail in Haney, M.A. (1985). Differential viscometer. I. A new approach to the measurement of the specific viscosity of polymer solutions. Journal of Applied Polymer Science, Vol. 30, 3023 - 3036., Haney, M.A. (1985). Differential viscometer. II. An on-line viscosity detector for size exclusion chromatography. Journal of Applied Polymer Science, Vol. 30, 3037 - 3049., and U.S. Patent No. 4,463,598, published on August 7, 1984 (the content of which is incorporated herein by reference to the extent not inconsistent with the present disclosure).

[0034] As shown in FIG. 1, a conventional viscometer 100 may include an inlet 101 fluidly coupled to a plurality of capillaries R1 - R4 (four are shown as 102, 104, 106, 108). In at least one embodiment, capillaries 102, 106 may form a first fluid flow line 105, and capillaries 104, 108 may form a second fluid flow line 103. The first fluid flow line 105 may include a "T" connection 113 inserted between capillaries 102, 106. The second fluid flow line 103 may include a "T" connection 112 inserted between capillaries 104, 108.

[0035] Any one or more of capillaries 102, 104, 106, 108 may have equal and matching resistances, or may have a known non - matching resistance relative to any one or more of the remaining capillaries 102, 104, 106, 108. The conventional viscometer 100 of FIG. 1 may include a delay reservoir or delay column 110 disposed downstream of the "T" connection 112. The delay reservoir 110 can delay or be configured to delay the entry of the sample flowing through the viscometer 100 into the reference capillary 108, thereby causing a measured resistance mismatch across or through the bridge, or the pressure transducer line 111 and / or the pressure transducer coupled to line 111. It should be understood that the outlet stream or outlet line 114 of the viscometer 100 can be diluted by only about 50% in concentration. Further, in the conventional viscometer 100, due to the lengths of capillaries 102, 104, 106, 108 and the associated flow splitting, a sample spreading effect is observed, whereby the elution stream exiting the detector via the outlet stream 114 generally spreads. Considering the above, when the conventional viscometer 100 shown in FIG. 1 is utilized in a series or series configuration, it is generally disposed towards or at the end of the series configuration so as to avoid dilution and sample spreading effects.

[0036] FIG. 2A shows a schematic diagram of a conventional sample cell 200 for a light scattering detector 242 according to the prior art. FIG. 2B shows an enlarged view of a portion of the sample cell 200 labeled 2B in FIG. 2A according to the prior art. The conventional sample cell 200 and the light scattering detector 242 are further described in detail in Haney, Max., "Light Scattering Detectors and Sample Cells for the Same". Patent Cooperation Treaty (PCT) PCT / US2019 / 012090, filed on January 2, 2019, the content of which is incorporated herein by reference to the extent not inconsistent with the present disclosure. As shown in FIGS. 2A and 2B, the sample cell 200 may include a body 202 that defines a flow path 204 extending axially through the body. The flow path 204 may define the volume of the sample cell 200. The flow path 204 may include a central axis or centerline 282 configured to extend therethrough and define a general orientation of the flow path 204. As shown in FIG. 2B, the flow path 204 and its central axis 282 may be aligned with or coaxial with a light beam 280 emitted from the laser 256 of the light scattering detector 242. The flow path 204 may include a cylindrical inner section 206 inserted between a first outer section 208 and a second outer section 210. The first outer section 208 may be frustoconical, and a first end 212 of the first outer section 208 may be in direct fluid communication with the inner section 206 and may have a cross-sectional area relatively smaller than the cross-sectional area at a second end 214 of the first outer section. The body 202 may be in direct fluid communication with the inner section 206 and may further define an inlet 216 configured to direct a sample to the inner section 206, such as the center of the inner section 206 of the flow path 204. The second outer section 210 may be frustoconical, and a first end 218 of the second outer section 210 may be in direct fluid communication with the inner section 206 and may have a cross-sectional area relatively smaller than the cross-sectional area at a second end 220 of the second outer section.

[0037] The body 202 may further define a first outlet 222 and a second outlet 224 that extends through the body. The first outlet 222 and the second outlet 224 may be configured to fluidly couple the respective second ends 214, 220 of the first outer section 208 and the second outer section 210 to a waste line or an outlet line 213 via a first outlet line 226 and a second outlet line 228, respectively. As shown in FIG. 2A, the body 202 may define a first recess 230 that axially extends therethrough. The first recess 230 may be in fluid communication with the first outer section 208 and configured to receive a first lens 232 of the light scattering detector 242. The body 202 may define a second recess 234 that axially extends therethrough. The second recess 234 may be in fluid communication with the second outer section 210 and configured to receive a second lens 236 of the light scattering detector 242. As shown in FIG. 2B, the body 202 may define an aperture 238 that radially extends therethrough. The aperture 238 may be in direct fluid communication with an inner section 206, such as the center of the inner section 206 of the flow path 204. The sample cell 200 may further include an optically transparent material 240 disposed within the aperture 238.

[0038] Generally, the sample cell 200 shown in FIGS. 2A and 2B may include a single inlet 216 and two outlets 226, 228. These two outlets may have a matching flow or flow rate. The sample cells 200 of FIGS. 2A and 2B maximize sensitivity while minimizing the spread of the band at the measurement point at least. It should be understood that the conventional sample cells 200 shown in FIGS. 2A and 2B are not ideally utilized in a series configuration. For example, a waste line or an outlet line 213 exiting the sample cell 200 may exhibit a spread of the sample. Considering the above, when a light scattering detector 242 including the conventional sample cells 200 shown in FIGS. 2A and 2B is utilized in series, it is generally disposed towards or at the end of a series configuration.

[0039] FIG. 2C shows a schematic diagram of an exemplary light scattering detector (LSD) 242 including the sample cell 200 shown in FIGS. 2A and 2B according to the prior art. It should be understood that both static and dynamic light scattering detectors are contemplated. The LSD 242 can be operatively coupled to a sample source or device 244 and can receive or be configured to receive a sample or effluent therefrom. For example, as shown in FIG. 2C, the LSD 242 can be fluidly coupled to the sample source or device 244 via line 246 and can be configured to receive the effluent therefrom. Exemplary sample sources or devices 244 can include, but are not limited to, chromatography devices capable of separating or configured to separate one or more analytes of a sample or eluate from each other. For example, the sample source or device 244 can be a liquid chromatography device capable of separating or configured to separate the analytes of an eluate from each other based on their respective charges (e.g., ion exchange chromatography), sizes (e.g., size exclusion or gel permeation chromatography), etc., as known in the art. In an exemplary embodiment, the LSD 242 is operatively coupled to a liquid chromatography device configured to separate analytes from each other based on their respective sizes. For example, the LSD 242 is operatively coupled to a liquid chromatography device including a gel permeation chromatography column.

[0040] LSD242 may include an exemplary sample cell 200, a collimated light beam such as laser 256, and one or more detectors 258, 260, 262 (three are shown) operatively coupled to each other. Detectors 258, 260, 262 can be any suitable detectors capable of receiving or configured to receive analyte scattered light. For example, any one or more of detectors 258, 260, 262 may be a photodetector such as a silicon photodetector. LSD242 may include one or more lenses 232, 236, 264, 266, 268 (five are shown) capable of or configured to refract, focus, attenuate, and / or collect the light transmitted through LSD242, and one or more mirrors 270, 272 (two are shown) capable of or configured to reflect or transfer the light transmitted through LSD242.

[0041] In at least one embodiment, the first lens 232 and the second lens 236 may be disposed on opposite sides of the sample cell 200 and may be configured to refract, focus, attenuate, and / or collect light passing therethrough. In another embodiment shown in FIGS. 2A and 2C, the body 202 of the sample cell 200 may define a first recess 230 and a second recess 234 that extend longitudinally or axially therethrough and are configured to receive the first lens 232 and the second lens 236, respectively. As shown in FIGS. 2A and 2C, each of the first and second lenses 232, 236 may define a convex surface along its respective first or outer end 248, 250. The first ends 248, 250 of the first and second lenses 232, 236 are shown as defining convex surfaces, but it should be understood that either one of the respective first ends 248, 250 of the first and second lenses 232, 236 may alternatively define a flat surface. As further shown in FIG. 2A, each of the first and second lenses 232, 236 may define a flat surface along its respective second or inner end 252, 254. The respective second ends 252, 254 of the first and second lenses 232, 236 may seal and / or at least partially define a flow path 204 that extends through the sample cell 200.

[0042] The laser 256 can be or can be any suitable laser configured to provide an optical beam 280 having a sufficient wavelength and / or power. For example, the laser 256 may be a diode laser, a solid-state laser, or the like. The laser 256 can be configured to emit the optical beam 280 through the sample cell 200. For example, as shown in FIG. 2C, the laser 256 may be disposed or arranged around the LSD 242 such that the optical beam 280 emitted from the LSD 242 passes through the sample cell 200. As further shown in FIG. 2C, a third lens 264 can be inserted between the sample cell 200 and the laser 256 and can be configured to focus the optical beam 280 directed toward and passing through the sample cell 200.

[0043] In at least one embodiment, at least one of mirrors 270, 272 can be associated with respective detectors 258, 260 and can be configured to reflect or transfer light (e.g., scattered light or analyte scattered light) toward respective detectors 258, 260. For example, as shown in FIG. 2C, a first mirror 270 can be disposed proximal to a first lens 232 and can be configured to reflect at least a portion of the light from the first lens 232 toward a first detector 258. In another example, a second mirror 272 can be disposed proximal to a second lens 236 and / or can be inserted between the second lens 236 and a third lens 264 and can be configured to reflect at least a portion of the light from the second lens 236 toward a second detector 260. In at least one embodiment, one or more lenses 266, 268 are inserted between the first and second mirrors 270, 272 and the first and second detectors 258, 260 to focus, refract, or otherwise direct the light from the mirrors 270, 272 onto the detectors 258, 260. For example, as shown in FIG. 2C, a fourth lens 266 can be inserted between the first detector 258 and the first mirror 270, and a fifth lens 268 can be inserted between the second detector 260 and the second mirror 272.

[0044] In at least one embodiment, at least one of detectors 258, 260, 262 can be configured to receive light (e.g., scattered light or analyte scattered light) from sample cell 200 without the aid or reflection of one of mirrors 270, 272. For example, as shown in FIGS. 2B and 2C, a third detector 262 can be disposed adjacent to or coupled to sample cell 200 and can be configured to receive light (e.g., scattered light) from sample cell 200 at an angle of approximately 90° relative to light beam 280. As further discussed herein, an optically transparent material or a sixth lens 240 can be configured to refract or direct the scattered light toward the third detector 262.

[0045] As shown in FIG. 2C, at least one of the sample cell 200, the first, second, and third lenses 232, 236, 264, and the first and second mirrors 270, 272 can be arranged parallel to, coaxial with, or otherwise aligned along the direction of the light beam 280 emitted by the laser 256. As further shown in FIG. 2C, each of the first and second detectors 258, 260 can be arranged or positioned to receive light (e.g., scattered light or analyte scattered light) from their respective mirrors 270, 272 in a direction generally perpendicular to the light beam 280 emitted by the laser 256. Each of the first and second mirrors 270, 272 can define a respective bore or path 274, 276 extending therethrough. For example, the first mirror 270 can define a bore 274 extending therethrough in a direction parallel to, coaxial with, or otherwise aligned with the light beam 280. Similarly, the second mirror 272 can define a bore 276 extending in a direction parallel to, coaxial with, or otherwise aligned with the light beam 280. The bores 274, 276 extending through their respective mirrors 270, 272 allow the light beam 280 emitted from the laser 256 to be transmitted through the first and second mirrors 270, 272, thereby preventing the light beam 280 from being reflected toward the first and second detectors 258, 260.

[0046] In at least one embodiment, the LSD 242 can include one or more screens or diaphragms 284, 286. For example, as shown in FIG. 2C, the first diaphragm can be inserted between the first lens 232 and the first mirror 270, and the second diaphragm can be inserted between the second mirror 272 and the lens 264. The diaphragms 284, 286 can be configured to "clean up," separate, or otherwise filter stray light (e.g., a halo of light) from the light beam 280. For example, the diaphragms 284, 286 can be capable of filtering stray light from the light beam 280 or can define holes or apertures (e.g., adjustable apertures / iris) configured to filter.

[0047] It should be understood that viscometers such as the conventional viscometer 100 shown in FIG. 1 and light scattering detectors such as the light scattering detector 242 of FIG. 2C are often used in conjunction with a refractometer 900 (FIGS. 9 and 10). For example, the viscometer 100 and the light scattering detector 242 are often fluidly and / or operably coupled to the refractometer 900. Conventional methods of coupling the viscometer 100 and the light scattering detector 242 to the refractometer 900 often require a three-way parallel flow split (such as that shown in FIG. 9) or a series configuration (such as that shown in FIG. 10). As is known in the art, maintaining a three-way parallel flow split is relatively difficult and presents a technical problem of increasing the spread of all three detectors (e.g., a viscometer, a light scattering detector, and a refractometer). Further, as is known in the art, a series configuration of three detectors will dilute or spread the downstream or subsequent detectors.

[0048] Considering the above, the inventors have surprisingly and unexpectedly found that combining the viscometer 100 and the light scattering detector 242 in a combined or single unit 300, 400 or “cell” addresses the aforementioned technical problems. In particular, the inventors have surprisingly and unexpectedly found that combining the viscometer 100 and the light scattering detector 242 in a single unit 300, 400 eliminates the need or requirement for a three-way parallel flow split (FIG. 9). The inventors have also surprisingly and unexpectedly found that the delay volumes and peak shapes of the viscometer 100 and the light scattering detector 242 are substantially identical or show a relatively close match when the viscometer 100 and the light scattering detector 242 are combined in a single unit 300, 400, as disclosed herein, compared to conventional methods that utilize series or parallel configurations. The combined or single unit 300, 400 that combines the viscometer 100 and the light scattering detector 242 can be readily utilized in a series configuration with another detector, such as a UV detector (not shown). For example, the single units 300, 400 may be utilized downstream of the UV detector in a series configuration. The single units 300, 400 that combine the viscometer 100 and the light scattering detector 242 may also be readily utilized in a parallel configuration with another detector, such as a refractometer, to determine concentration.

[0049] Figure 3 shows a schematic diagram of an exemplary single unit device 300 incorporating a viscometer 100, a light scattering detector 242, and its sample cell 200, according to one or more disclosed embodiments. The viscometer 100, the light scattering detector 242, and its sample cell 200 may be similar in some respects to the above-described viscometer 100, light scattering detector 242, and sample cell 200, and thus may be best understood with reference to the descriptions of FIGS. 1 and 2A - 2C. Like numbers indicate like components and will not be described in detail again. As illustrated in FIG. 3, the light scattering detector 242 is disposed downstream or after a "T" connection 112 that couples the sample flowing through the capillary 104 to a pressure transducer 302 and a capillary 108. The "T" connection 112 may also be referred to as a "T" connector or union. Exemplary "T" connectors may be, but are not limited to, couplings, Ts, and crosses for high pressure HPLC connections, or may include them, and they are commercially available from Thermo Fisher Scientific (TM) (catalog numbers: 03 - 052 - 437, 03 - 052 - 438, 03 - 170 - 306, etc.). As further illustrated in FIG. 3, the light scattering detector 242 is disposed upstream of a delay column or dilution reservoir 110. For the sake of brevity, the sample cell 200 is also utilized in the schematic diagram of FIG. 3 to represent the LSD242 and its sample cell 200. Surprisingly and unexpectedly, it has been found that the particular location of the light scattering detector 242, particularly its sample cell 200, significantly affects the observed matched width of the viscometer 100. The surprising and unexpected results are demonstrated in the following examples.

[0050] FIG. 4 shows a schematic diagram of another exemplary single unit device 400 incorporating viscometer 100, light scattering detector 242, and its sample cell 200 according to one or more disclosed embodiments. Viscometer 100, light scattering detector 242, and its sample cell 200 may be similar in some respects to the viscometer 100, light scattering detector 242, and sample cell 200 described above, and thus may be best understood by reference to the descriptions of FIGS. 1 and 2A-2C, where like numbers indicate like components and will not be described in detail again. As shown in FIG. 4, the single unit device 400 can include one or more purge lines (two are shown as 402, 404), and each of the purge lines 402, 404 has at least one purge valve 406, 408 coupled thereto. The purge lines 402, 404 and purge valves 406, 408 coupled thereto can be capable of purging the pressure transducer 302 of the viscometer 100, or be configured to purge, without introducing any stagnant solvent into the sample cell 200 of the light scattering detector 242. Further, the purge lines 402, 404 and purge valves 406, 408 coupled thereto allow a liquid or sample to bypass the light scattering detector 242 and its sample cell 200, thereby providing a means for changing the solvent or conditioning column. The purge lines 402, 404 and purge valves 406, 408 coupled thereto can also allow for solvent change and / or column conditioning while keeping the light scattering detector 242 free of air, contaminants, and particulates. FIG. 4 shows purge lines 402, 404 coupled to the outlet 114, but it should be understood that the purge lines 402, 404 can be fluidly coupled to any waste or outlet line capable of purging the transducer 302 or configured to purge that transducer. The purge lines 402, 404 need not fluidly communicate to a common outlet 114.

[0051] Combining the viscometer 100, the light scattering detector 242, and / or its sample cell 200, and the single unit devices 300, 400 described in this specification shown in FIGS. 3 and 4 provide one or more of the following technical effects. (1) Minimize the peak broadening and offset between the viscometer 100 and the light scattering detector 242 as compared to the conventional series and parallel configurations of the viscometer and the light scattering detector. (2) Minimize the conventional mathematical corrections, which are known to reduce resolution or introduce irrelevant noise and artifacts, especially when a multi-detector ratio is required. (3) Result in minimal or relatively small shape (e.g., peak) differences as compared to conventional means and methods. (4) Result in minimal or relatively small offsets between the viscometer 100 and the light scattering detector 242 as compared to conventional configurations or methods that utilize a viscometer and a light scattering detector (e.g., series or parallel configurations). (5) Minimize sample dilution in either the viscometer 100 or the light scattering detector 242. (6) Minimize the possibility or opportunity of introducing a particular substance into the light scattering detector 242, including when the viscometer detector 100 is purging its transducer 302. (7) Maintain a constant or substantially constant backpressure on the light scattering detector 242 to minimize solvent release from its sample cell 200, and at the same time, without relying on adding more external tubes for flow splitting balance or backpressure to other detectors, such as in a parallel configuration or a series configuration. Regarding technical effect (3), it should be understood by those skilled in the art that the "shape" of a chromatographic peak is defined or refers to the peak width at half height (50% height). Further, regarding the technical effect (3) that results in minimal or relatively small shape differences as compared to the standard and series configurations and compared to conventional means, it is noted that the effect is more prominent or easily observable when the sample is a monodisperse standard injected into a liquid chromatograph.

[0052] Figures 3 and 4 show respective single unit devices 300, 400 that utilize a combination of an exemplary viscometer 100 and an exemplary light scattering detector 242, it being understood that the light scattering detector 242 can be replaced with, and / or supplemented by, any other suitable detector. For example, the light scattering detector 242 can be replaced with, and / or supplemented by, any other suitable detector capable of providing, or configured to provide, any one or more of the technical effects disclosed herein. Exemplary detectors contemplated can be, but are not limited to, a refractive index (RI) detector, an ultraviolet (UV) detector, an infrared (IR) detector, a fluorescence detector, a conductivity detector, or combinations thereof, or those including them.

[0053] The following numbered paragraphs disclose one or more exemplary variations of the subject matter of this application.

[0054] 1. A single unit device comprising: an inlet line; a first fluid flow line in fluid communication with the inlet line, the first fluid flow line comprising a first capillary in direct fluid communication with the inlet line, a second capillary disposed in series with the first capillary, and a first T-connector inserted between the first capillary and the second capillary of the first fluid flow line; a second fluid flow line in fluid communication with the inlet line, the second fluid flow line comprising a first capillary in direct fluid communication with the inlet line, a second capillary disposed downstream of the first capillary, and a second T-connector inserted between the first capillary and the second capillary of the second fluid flow line; a light scattering detector disposed downstream of the second T-connector and upstream of the second capillary of the second fluid flow line; a pressure transducer line fluidly coupling the first T-connector to the second T-connector; a pressure transducer disposed within the pressure transducer line; and an outlet stream in fluid communication with the second capillary of the first fluid flow line and the second capillary of the second fluid flow line.

[0055] 2. The single unit device according to paragraph 1, further comprising a dilution reservoir disposed downstream of the light scattering detector and upstream of the second capillary of the second fluid flow line.

[0056] 3. The light scattering detector includes a sample cell, the sample cell is fluidly coupled to the first capillary of the second fluid flow line and has an inlet disposed downstream of the first capillary of the second fluid flow line, and is fluidly coupled to the second capillary of the second fluid flow line and has a first outlet and a second outlet disposed upstream of the second capillary of the second fluid flow line. The single unit device according to paragraph 1 or 2.

[0057] 4. The sample cell further includes a body, the body defines a flow path that axially extends through the body, the flow path includes a cylindrical inner section inserted between a first outer section and a second outer section, the first outer section is frustoconical, the first end of the first outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively smaller than the cross-sectional area at the second end of the first outer section, the body is in direct fluid communication with the inner section and further defines an inlet configured to direct a sample toward the inner section of the flow path, the body further defines a first outlet and a second outlet, and the first outlet and the second outlet are configured to fluidly couple the first outer section and the second outer section to an outlet stream via the second capillary of the second fluid flow line. The single unit device according to paragraph 3.

[0058] 5. The second outer section of the sample cell is frustoconical, the first end of the second outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively smaller than the cross-sectional area at the second end of the second outer section. The single unit device according to paragraph 4.

[0059] 6. The body defines a first recess extending axially therethrough, the first recess being in fluid communication with the first outer section and configured to receive the first lens of the light scattering detector, the single unit device according to paragraph 4 or 5.

[0060] 7. The body defines a second recess extending axially therethrough, the second recess being in fluid communication with the second outer section and configured to receive the second lens of the light scattering detector, the single unit device according to paragraph 6.

[0061] 8. The body of the sample cell defines an aperture extending radially therethrough, the aperture being in direct fluid communication with the inner section of the flow path, the single unit device according to any one of paragraphs 4 to 7.

[0062] 9. The single unit device according to paragraph 8, further comprising an optically transparent material disposed within the aperture.

[0063] 10. The single unit device according to any one of paragraphs 1 to 9, further comprising one or more purge lines fluidly coupled to the pressure transducer and configured to purge the pressure transducer.

[0064] 11. The single unit device according to paragraph 10, further comprising respective purge valves disposed in each of the one or more purge lines, and optionally, each of the one or more purge lines is fluidly coupled to the outlet stream.

[0065] 12. The light scattering detector further comprises a laser for emitting a light beam, and the flow path of the sample cell has a center line aligned with the light beam, the single unit device according to any one of paragraphs 4 to 11.

[0066] 13. The single-unit device according to paragraph 12, further comprising at least one detector operably coupled to the sample cell and configured to receive scattered light emitted from the sample cell.

[0067] 14. A system comprising the single-unit device according to any one of paragraphs 1 to 13 and a refractometer operably coupled to the single-unit device.

[0068] 15. The system according to paragraph 15, wherein the single-unit device and the refractometer are operably coupled in series with each other.

[0069] 16. The system according to paragraph 14 or 15, wherein the refractometer is disposed upstream of the single-unit device.

[0070] 17. A method of using the system according to any one of paragraphs 14 to 16, the method comprising flowing a sample through the refractometer and flowing the sample through the single-unit device.

[0071] 18. Flowing the sample through the single-unit device includes flowing the sample from an inlet line to an outlet stream via a first fluid flow line and a second fluid flow line.

[0072] 19. Flowing the sample through the second fluid flow line includes flowing the sample through a first capillary and a second capillary of the second fluid flow line and flowing the sample through a light scattering detector inserted between the first capillary and the second capillary of the second fluid flow line.

[0073] 20. The method according to any one of paragraphs 17 to 19, further comprising flowing the sample from the refractometer to the single-unit device.

Example

[0074] The examples and other embodiments described herein are illustrative and are not intended to limit the full scope of the compositions and methods of the present disclosure. Equivalent changes, modifications, and variations of specific embodiments, materials, compositions, and methods can be made within the scope of the present disclosure with substantially similar results.

[0075] Example 1 The single unit device 400 described in detail above and represented by FIG. 4 was utilized in measuring three light scattering angles and the viscometer signal. In particular, low angle light scattering (LALS), right angle light scattering (RALS), and high angle light scattering (HALS) were measured at approximately 10°, approximately 90°, and approximately 170°, respectively. The sample utilized was a narrow polystyrene standard having a nominal molecular weight of approximately 96,100 Da, which is commercially available from Tosoh Bioscience, LLC., King of Prussia, PA. This sample utilized tetrahydrofuran (THF) as the solvent at a concentration of approximately 1.05 mg / mL. The conditions for operating the single unit device 400 were, as follows, an injection volume of approximately 100 μL, a flow rate of approximately 1 mL / min, and the use of a chromatography column GMHHR-H commercially available from Tosoh Bioscience, LLC. FIG. 5 shows a plot of the measured values. As shown in FIG. 5, all three of the observed light scattering angles, and the observed viscometer signal, showed measurements that were simultaneous or substantially simultaneous and had the same or substantially the same shape. It should be understood that the observed light scattering angles and viscometer signal shown in FIG. 5 are raw signals. In other words, the observed light scattering angles and viscometer signal are raw signals that have not been smoothed, deconvolved, shifted, or otherwise manipulated.

[0076] Example 2 Those skilled in the art should understand that the chromatographic peak shape of the monodisperse component can be numerically well-defined by describing the peak width at half the height (50% of the height). It should also be understood that those skilled in the art can adequately measure the tailing by measuring the peak width at 1 / 5 of the height (20% of the height).

[0077] A comparative single-unit device having a configuration different from that of the single-unit device 400 of Example 1 was evaluated. Specifically, as shown in FIG. 6, a comparative single-unit device 600 incorporating a viscometer 100 and a light scattering detector 242 and having Configuration A was tested and is shown in FIG. 4 for comparison with the exemplary single-unit device 400 of Example 1. The viscometer 100, light scattering detector 242, and sample cell 200 in FIG. 6 may be similar to the above-described viscometer 100, light scattering detector 242, and sample cell 200 in some respects and can thus be best understood by referring to the descriptions of FIGS. 1, 2A - 2C, 3, and 4. Like numbers indicate like components and will not be described in detail again. As shown in FIG. 6, the light scattering detector 242 and its sample cell 200 were installed after or downstream of the capillary 104 and before or upstream of the T-joint 112. The viscometer detector 100 and the right-angle light scattering (RALS) detector 262 were monitored simultaneously, and the baseline was subtracted. The results of the comparative single-unit device 600 of Example 1 and the exemplary single-unit device 400 are shown in FIGS. 7 and 8, respectively. The respective differences or deltas in the peak widths at 50% (e.g., shape), 20% (e.g., tailing), and the peak retention volume delta (Δ) of the comparative single-unit device 600 and the exemplary single-unit device 400 of Example 1 (FIG. 4) are summarized in Table 1 below.

Table 1

[0078] As shown in Table 1 and FIGS. 7 and 8, numerically and visually, in the exemplary single unit device 400 of Example 1 (FIG. 4), there were significant, surprising, and unexpected improvements in the synchronization of the peak elution shape and peak time, whereby the installation of the light scattering detector 242 and its sample cell 200 in the configurations shown in FIGS. 3 and 4 was advantageous.

[0079] Example 3 To compare the series / serial configuration, parallel configuration, and combined configuration, a refractometer was installed in series before the parallel and series configurations so as to function as a reference detector. The comparison was made using the same light scattering detector 242 and viscometer 100 configured as follows: (1) parallel detector (shown in FIG. 9), (2) series / serial detector with a viscometer 100 first (shown in FIG. 10), and (3) series / serial detector with a "combined" configuration utilizing the exemplary single unit device 400 of the present disclosure (shown in FIG. 11). The results are summarized in Table 2 below. The respective plots of the color peaks observed / measured in each of the parallel configuration, series configuration, and combined configuration are shown in FIGS. 12, 13, and 14, respectively.

Table 2

[0080] Note that the refractometer detector cell volume and outlet tube were approximately 150 μL, which accounted for most of the observed delay volume shown in Table 2. It was observed that there were significant, surprising, and unexpected improvements in the average detector shape in the "combined" configuration (shown in FIG. 14) compared to the reference refractometer. The average retention volume shift was similar to that of the series configuration, but had the advantage of no reduction in the RALS area. The combined configuration is even more advantageous than the parallel configuration, which has approximately half of the recovered viscometer area due to the reduced flow rate in parallel. Therefore, utilizing the "combined configuration" or the exemplary single unit device 400 provided the maximum signal and recovered the best, or closest, peak shape for the refractive index detector.

[0081] The present disclosure has been described with reference to exemplary embodiments. Although a limited number of embodiments have been shown and described, those skilled in the art will understand that modifications can be made to these embodiments without departing from the principles and spirit of the foregoing detailed description. It is intended that the present disclosure be construed to include all such modifications and variations as long as they come within the scope of the appended claims or their equivalents.

Claims

1. A single-unit device, Entrance line, A first fluid flow line that is in fluid communication with the inlet line, the first fluid flow line is A first capillary tube that is in direct fluid communication with the aforementioned inlet line, A second capillary tube is arranged in series with the first capillary tube, A first fluid flow line comprising: a first T-connector inserted between the first capillary and the second capillary of the first fluid flow line; A second fluid flow line that is in fluid communication with the inlet line, the second fluid flow line is A first capillary tube that is in direct fluid communication with the aforementioned inlet line, A second capillary tube is disposed downstream of the first capillary tube, A second fluid flow line comprising: a second T-connector inserted between the first capillary and the second capillary of the second fluid flow line; A light scattering detector is disposed downstream of the second T-connector and upstream of the second capillary tube of the second fluid flow line, A pressure transducer line that fluidly couples the first T-connector to the second T-connector, A pressure transducer disposed within the aforementioned pressure transducer line, A single-unit device comprising the second capillary of the first fluid flow line, and an outlet stream that is in fluid communication with the second capillary of the second fluid flow line.

2. The single-unit device according to claim 1, further comprising a dilution reservoir disposed downstream of the light scattering detector and upstream of the second capillary of the second fluid flow line.

3. The light scattering detector comprises a sample cell, and the sample cell is A fluid coupling is provided to the first capillary of the second fluid flow line, and an inlet is located downstream of the first capillary of the second fluid flow line, The single-unit device according to claim 1, comprising a first outlet and a second outlet that are fluidly coupled to the second capillary of the second fluid flow line and disposed upstream of the second capillary of the second fluid flow line.

4. The aforementioned sample cell is The apparatus further comprises a main body, the main body defining a flow path extending axially through the main body, the flow path comprising a cylindrical inner section inserted between a first outer section and a second outer section, The first outer section is frustoconical in shape, and the first end of the first outer section is in direct fluid communication with the inner section, and has a cross-sectional area that is relatively smaller than the cross-sectional area of ​​the second end of the first outer section. The main body further defines the inlet which is directly in fluid communication with the inner section and is configured to direct the sample toward the inner section of the flow path. The single-unit device according to claim 3, wherein the body further defines the first outlet and the second outlet, and the first outlet and the second outlet are configured to fluidly couple the first outer section and the second outer section to the outlet stream via the second capillary of the second fluid flow line.

5. The single-unit device according to claim 4, wherein the second outer section of the sample cell is frustoconical, the first end of the second outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively smaller than the cross-sectional area at the second end of the second outer section.

6. The single-unit device according to claim 4 or 5, wherein the body defines a first recess extending axially through the body, the first recess being in fluid communication with the first outer section and configured to receive a first lens of the light scattering detector.

7. The single-unit device according to claim 6, wherein the main body defines a second recess extending axially through the main body, the second recess being in fluid communication with the second outer section and configured to receive a second lens of the light scattering detector.

8. The single-unit device according to claim 4, wherein the body of the sample cell defines an aperture extending radially through the body, and the aperture is in direct fluid communication with the inner section of the flow path.

9. The single-unit device according to claim 8, further comprising an optically transparent material disposed within the aperture.

10. The single-unit device according to claim 1, further comprising one or more purge lines fluidly coupled to the pressure transducer and configured to purge the pressure transducer.

11. The single-unit device according to claim 10, further comprising a purge valve disposed in each of the one or more purge lines, wherein each of the one or more purge lines is optionally fluid-coupled to the outlet stream.

12. The single-unit device according to claim 4, wherein the light scattering detector further comprises a laser for emitting a light beam, and the channel of the sample cell has a center line that is aligned with the light beam.

13. The single-unit device according to claim 12, wherein the light scattering detector further comprises at least one detector operably coupled to the sample cell and configured to receive scattered light emitted from the sample cell.

14. It is a system, A single unit device according to any one of claims 1 to 5, A system comprising a refractometer operably coupled to the aforementioned single-unit device.

15. The system according to claim 14, wherein the single-unit device and the refractometer are coupled in series with respect to each other so as to be operable.

16. The system according to claim 14, wherein the refractometer is disposed upstream of the single-unit device.

17. A method of using the system described in claim 14, wherein the method is The process involves flowing the sample through the aforementioned refractometer, A method comprising flowing the sample through the single-unit device.

18. The method according to claim 17, wherein flowing the sample through the single-unit device includes flowing the sample from the inlet line to the outlet stream via the first fluid flow line and the second fluid flow line.

19. The method according to claim 18, wherein flowing the sample through the second fluid flow line includes flowing the sample through the first capillary and the second capillary of the second fluid flow line, and flowing the sample through the light scattering detector inserted between the first capillary and the second capillary of the second fluid flow line.

20. The method according to claim 17, further comprising flowing the sample from the refractometer into the single-unit device.

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