Patent Description:
While conventional light scattering detectors have proven to be effective for determining the physical attributes of a wide variety of molecules, conventional light scattering detectors are limited in their ability to analyze small molecules. For example, conventional light scattering detectors often lack the sensitivity and/or resolution to measure Rg of molecules having a radius of gyration of less than about <NUM>. In view of the foregoing, conventional light scattering detectors often incorporate lasers having relatively greater power or energy to increase the sensitivity of the detectors. Incorporating lasers with greater power, however, is cost prohibitive and often requires larger instruments due to the relatively larger footprint of the lasers. Alternatively, the volume of the sample cells in conventional light scattering detectors can been increased to increase the intensity of scattered light. Increasing the volume of conventional sample cells, however, leads to excessive peak broadening.

What is needed, then, are improved light scattering detectors and sample cells thereof, and methods for increasing the sensitivity and/or resolution of the light scattering detectors without increasing peak broadening.

<CIT> discloses a scattered light photometer. <CIT> discloses a fiber-coupled liquid sample analyzer with liquid flow cell. <CIT> discloses a housing for a flow cytometry apparatus with particle unclogging feature. <CIT> discloses a miniature low angle laser light scattering detector. <CIT> discloses a gaseous sample room.

This summary is intended merely to introduce a simplified summary of some aspects of one or more implementations of the present disclosure. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. This summary is not an extensive overview, nor is it intended to identify key or critical elements of the present teachings, nor to delineate the scope of the disclosure. Rather, its purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description below.

The foregoing and/or other aspects and utilities embodied in the present disclosure may be achieved by providing a sample cell for a light scattering detector. The sample cell includes a body defining a flowpath extending axially therethrough. The flowpath comprises a cylindrical inner section interposed between a first outer section and a second outer section. The first outer section is frustoconical, and a first end portion of the first outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively less than a cross-sectional area at a second end portion thereof. The body further defines an inlet in direct fluid communication with the inner section and configured to direct a sample to the inner section of the flowpath.

The second outer section is frustoconical, and a first end portion of the second outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively less than a cross-sectional area at a second end portion thereof.

In at least one implementation, the body further defines a first outlet and a second outlet extending therethrough, wherein the first outlet and the second outlet are configured to fluidly couple the respective second end portions of the first and second outer sections with a waste line.

In at least one implementation, the body defines a first recess extending axially therethrough, the first recess in fluid communication with the first outer section and configured to receive a first lens of the light scattering detector.

In at least one implementation, the body defines a second recess extending axially therethrough, the second recess in fluid communication with the second outer section and configured to receive a second lens of the light scattering detector.

In at least one implementation, the body defines an aperture extending radially therethrough, wherein the aperture is in direct fluid communication with the inner section of the flowpath.

In at least one implementation, the sample cell further comprises an optically transparent material disposed in the aperture.

The foregoing and/or other aspects and utilities embodied in the present disclosure may be achieved by providing a light scattering detector. The light scattering detector may include: a laser configured to emit a beam of light; a sample cell comprising a body defining a flowpath extending therethrough, the flowpath having a centerline aligned with the beam of light, the flowpath comprising a cylindrical inner section interposed between a first outer section and a second outer section. The first outer section is frustoconical, and a first end portion of the first outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively less than a cross-sectional area at a second end portion thereof. The body further defines an inlet in direct fluid communication with the inner section and configured to direct a sample to the inner section of the flowpath. The light scattering detector may also include at least one detector operably coupled with the sample cell and configured to receive scattered light emitted from the sample cell.

In at least one implementation, the second outer section is frustoconical, and a first end portion of the second outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively less than a cross-sectional area at a second end portion thereof.

In at least one implementation, the light scattering detector may include a first lens and a second lens, the first lens disposed adjacent the first outer section of the flowpath, and the second lens disposed adjacent the second outer section of the flowpath.

In at least one implementation, the light scattering detector further includes a first mirror and a first detector, the first mirror disposed proximal the first lens and configured to reflect forward scattered light from the sample cell to the first detector.

In at least one implementation, the light scattering detector may further include a second mirror and a second detector, the second mirror disposed proximal the second lens and configured to reflect back scattered light from the sample cell to the second detector.

In at least one implementation, the light scattering detector may further include a third detector disposed in the aperture and configured to receive right angle scattered light from the sample cell.

The foregoing and/or other aspects and utilities embodied in the present disclosure may be achieved by providing a method of using any one of the light scattering detectors disclosed herein. The method may include emitting the beam of light from the laser to and through the flowpath of the sample cell, flowing a sample to the inner section of the flowpath via the inlet of the sample cell, flowing a first portion of the sample from the inner section to and through the first frustoconical outer section from the first end portion to the second end portion thereof, and flowing the first portion of the sample from the second end portion of the first frustoconical outer section to the waste line via the first outlet.

In at least one implementation, the method may further include flowing a second portion of the sample from the inner section to and through the second frustoconical outer section from the first end portion to the second end portion thereof, and flowing the second portion of the sample from the second end portion of the second frustoconical outer section to the waste line via the second outlet.

In at least one implementation, the method may also include directing the forward scattered light emitted from the flowpath to the first detector with the first mirror.

In at least one implementation, the method may further include directing the back scattered light emitted form the flowpath to the second detector with the second mirror.

In at least one implementation, the method may include directing the right angle scattered light emitted from the flowpath to the third detector.

Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating some typical aspects of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate varying implementations of the present disclosure. These and/or other aspects and advantages in the implementations of the disclosure will become apparent and more readily appreciated from the following description of the various implementations, taken in conjunction with the accompanying drawings. It should be noted that some details of the drawings have been simplified and are drawn to facilitate understanding of the present disclosure rather than to maintain strict structural accuracy, detail, and scale. These drawings/figures are intended to be explanatory and not restrictive.

The following description of various typical aspect(s) is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses.

As used throughout this disclosure, ranges are used as shorthand for describing each and every value that is within the range. It should be appreciated and understood that the description in a range format is merely for convenience and brevity, and should not be construed as an inflexible limitation on the scope of any embodiments or implementations disclosed herein. Accordingly, the disclosed range should be construed to have specifically disclosed all the possible subranges as well as individual numerical values within that range. As such, any value within the range may be selected as the terminus of the range. For example, description of a range such as from <NUM> to <NUM> should be considered to have specifically disclosed subranges such as from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, etc., as well as individual numbers within that range, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc. This applies regardless of the breadth of the range.

As used herein, the term or expression "sensitivity" may refer to the ratio of signal to noise. It should be appreciated by one having ordinary skill in the art that increasing laser power does not necessarily improve the sensitivity.

<FIG> illustrates a schematic view of an exemplary light scattering detector (LSD) <NUM> including an exemplary sample cell <NUM>, according to one or more implementations. The LSD <NUM> may be operably coupled with a sample source or device <NUM>, and capable of or configured to receive a sample or effluent therefrom. For example, as illustrated in <FIG>, the LSD <NUM> may be fluidly coupled with the sample source or device <NUM> via line <NUM> and configured to receive the effluent therefrom. Illustrative sample sources or devices <NUM> may include, but are not limited to, a chromatography instrument capable of or configured to separate one or more analytes of a sample or eluent from one another. For example, the sample source or device <NUM> may be a liquid chromatography instrument capable of or configured to separate the analytes of the eluent from one another based on their respective charges (e.g., ion exchange chromatography), sizes (e.g., size-exclusion or gel permeation chromatography), or the like. In an exemplary implementation, the LSD <NUM> is operably coupled with a liquid chromatography instrument configured to separate the analytes from one another based on their respective sizes. For example, the LSD <NUM> is operably coupled with a liquid chromatography instrument including gel permeation chromatography columns.

The LSD <NUM> may include the exemplary sample cell <NUM>, a collimated beam of light such, such as a laser <NUM>, and one or more detectors <NUM>, <NUM>, <NUM> (three are shown) operably coupled with one another. The detectors <NUM>, <NUM>, <NUM> may be any suitable detector capable of or configured to receive analyte scattered light. For example, any one or more of the detectors <NUM>, <NUM>, <NUM> may be a photo-detector, such as a silicon photo-detector. The LSD <NUM> may include one or more lenses <NUM>, <NUM>, <NUM>, <NUM>, <NUM> (five are shown) capable of or configured to refract, focus, attenuate, and/or collect light transmitted through the LSD <NUM>, and one or more mirrors <NUM>, <NUM> (two are shown) capable of or configured to reflect or redirect the light transmitted through the LSD <NUM>.

In at least one implementation, a first lens <NUM> and a second lens <NUM> may be disposed on opposing sides of the sample cell <NUM> and configured to refract, focus, attenuate, and/or collect light transmitted therethrough. In another implementation, a body <NUM> of the sample cell <NUM> may define recesses <NUM>, <NUM> configured to receive the first and second lenses <NUM>, <NUM>. For example, as illustrated in <FIG> and further illustrated in detail in <FIG>, the body <NUM> of the sample cell <NUM> may define a first recess <NUM> and a second recess <NUM> extending longitudinally or axially therethrough, and configured to receive the first lens <NUM> and the second lens <NUM>, respectively. As illustrated in <FIG> and <FIG>, each of the first and second lenses <NUM>, <NUM> may define a convex surface along respective first or outer end portions <NUM>, <NUM> thereof. While the first end portions <NUM>, <NUM> of the first and second lenses <NUM>, <NUM> are illustrated as defining convex surfaces, it should be appreciated that any one of the respective first end portions <NUM>, <NUM> of the first and second lenses <NUM>, <NUM> may alternatively define a flat surface. As further illustrated in <FIG>, each of the first and second lenses <NUM>, <NUM> may define a flat surface along respective second or inner end portions <NUM>, <NUM> thereof. As further described herein, the respective second end portions <NUM>, <NUM> of the first and second lenses <NUM>, <NUM> may seal and/or at least partially define a channel or flowpath <NUM> extending through the sample cell <NUM>.

The laser <NUM> may be any suitable laser capable of or configured to provide a beam of light <NUM> having sufficient wavelength and/or power. For example, the laser <NUM> may be a diode laser, a solid state laser, or the like. The laser <NUM> may be configured to emit the beam of light <NUM> through the sample cell <NUM>. For example, as illustrated in <FIG>, the laser <NUM> may be arranged or disposed about the LSD <NUM> such that the beam of light <NUM> emitted therefrom is transmitted through the sample cell <NUM>. As further illustrated in <FIG>, a third lens <NUM> may be interposed between the sample cell <NUM> and the laser <NUM> and configured to focus the beam of light <NUM> directed to and through the sample cell <NUM>.

In at least one implementation, at least one of the mirrors <NUM>, <NUM> may be associated with a respective detector <NUM>, <NUM>, and configured to reflect or redirect the light (e.g., scattered light or analyte scattered light) towards the respective detector <NUM>, <NUM>. For example, as illustrated in <FIG>, a first mirror <NUM> may be disposed proximal the first lens <NUM> and configured to reflect at least a portion of the light from the first lens <NUM> towards a first detector <NUM>. In another example, a second mirror <NUM> may be disposed proximal the second lens <NUM> and/or interposed between the second and third lenses <NUM>, <NUM>, and configured to reflect at least a portion of the light from the second lens <NUM> towards a second detector <NUM>. In at least one implementation, one or more lenses <NUM>, <NUM> may be interposed between the first and second mirrors <NUM>, <NUM> and the first and second detectors <NUM>, <NUM> to focus, refract, or otherwise direct the light from the mirrors <NUM>, <NUM> to the detectors <NUM>, <NUM>. For example, as illustrated in <FIG>, a fourth lens <NUM> may be interposed between the first detector <NUM> and the first mirror <NUM>, and a fifth lens <NUM> may be interposed between the second detector <NUM> and the second mirror <NUM>.

In at least one implementation, at least one of the detectors <NUM>, <NUM>, <NUM> may be configured to receive the light (e.g., scattered light or analyte scattered light) from the sample cell <NUM> without the aid or reflection of one of the mirrors <NUM>, <NUM>. For example, as illustrated in <FIG> and <FIG>, a third detector <NUM> may be disposed adjacent to or coupled with the sample cell <NUM> and configured to receive the light (e.g., scattered light) from the sample cell <NUM> at an angle of about <NUM>° with respect to the beam of light <NUM>. As further discussed herein, an optically transparent material or a sixth lens <NUM> may be configured to refract or direct the scattered light toward the third detector <NUM>.

As illustrated in <FIG>, at least one of the sample cell <NUM>, the first, second, and third lenses <NUM>, <NUM>, <NUM>, and the first and second mirrors <NUM>, <NUM> may be disposed parallel, coaxial, or otherwise aligned with one another along a direction of the beam of light <NUM> emitted by the laser <NUM>. As further illustrated in <FIG>, each of the first and second detectors <NUM>, <NUM> may be disposed or positioned to receive light (e.g., scattered light or analyte scattered light) from the respective mirrors <NUM>, <NUM> in a direction generally perpendicular to the beam of light <NUM> emitted by the laser <NUM>. Each of the first and second mirrors <NUM>, <NUM> may define a respective bore or pathway <NUM>, <NUM> extending therethrough. For example, the first mirror <NUM> may define a bore <NUM> extending therethrough in a direction parallel, coaxial, or otherwise aligned with the beam of light <NUM>. Similarly, the second mirror <NUM> may define a bore <NUM> extending therethrough in the direction parallel, coaxial, or otherwise aligned with the beam of light <NUM>. It should be appreciated that the bores <NUM>, <NUM> extending through the respective mirrors <NUM>, <NUM> may allow the beam of light <NUM> emitted from the laser <NUM> to be transmitted through the first and second mirrors <NUM>, <NUM> to thereby prevent the beam of light <NUM> from being reflected towards the first and second detectors <NUM>, <NUM>.

<FIG> illustrates an enlarged view of the portion of the exemplary LSD <NUM> indicated by the box labeled 1D of <FIG>, according to one or more implementations. As previously discussed, the body <NUM> of the sample cell <NUM> may at least partially define the channel or flowpath <NUM> extending therethrough. For example, as illustrated in <FIG>, an inner surface <NUM> of the body <NUM> may at least partially define the flowpath <NUM> extending therethrough. The flowpath <NUM> may define a volume of the sample cell <NUM>. The flowpath <NUM> may include a central axis or centerline <NUM> extending therethrough and configured to define a general orientation of the flowpath <NUM>. As illustrated in <FIG>, the flowpath <NUM> and the central axis <NUM> thereof may be aligned or coaxial to the beam of light <NUM> emitted from the laser <NUM>. The flowpath <NUM> of the sample cell <NUM> may be interposed between the first and second lenses <NUM>, <NUM>. In at least one implementation, the first and second lenses <NUM>, <NUM> may sealingly engage the body <NUM> of the sample cell <NUM> on opposing sides thereof to thereby prevent a flow of the sample or effluent from the flowpath <NUM> via the interface between the body <NUM> and the respective first and second lenses <NUM>, <NUM>. In another implementation, a seal (e.g., gasket, O-ring, etc.) (not shown) may be disposed between the body <NUM> and the first and second lenses <NUM>, <NUM> to provide a fluid tight seal therebetween.

The flowpath <NUM> includes an inner section <NUM> and two outer sections <NUM>, <NUM> disposed along the centerline <NUM> thereof. As illustrated in <FIG>, the inner section <NUM> is interposed between the two outer sections <NUM>, <NUM>. The inner section <NUM> is fluidly coupled with and configured to receive a sample or effluent from the sample source <NUM>. For example, as illustrated in <FIG> with continued referenced to <FIG>, the body <NUM> of the sample cell <NUM> may define an inlet <NUM> extending therethrough and configured to fluidly couple the sample source <NUM> with the inner section <NUM> via line <NUM>. In a preferred implementation, the inlet <NUM> is configured such that the sample from the sample source <NUM> is directed to the middle or center of the flowpath <NUM> or the inner section <NUM> thereof.

The inner section <NUM> is cylindrical or defines a cylindrical volume, and may have a circular cross-sectional profile. It should be appreciated, however, that the cross-sectional profile may be represented by any suitable shape and/or size. For example, the cross-sectional profile may be elliptical, rectangular, such as a rounded rectangle, or the like. The inner section <NUM> may have any suitable dimension. In at one implementation, the inner section <NUM> may have a length extending between the two outer sections <NUM>, <NUM> of from about <NUM> to about <NUM> or greater. For example, the inner section <NUM> may have a length of from about <NUM>, about <NUM>, about <NUM>, about <NUM>, or about <NUM> to about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, or greater. In another example, the inner section <NUM> may have a length of from about <NUM> to about <NUM>, about <NUM> to about <NUM>, about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM> to about <NUM>. In a preferred implementation, the inner section <NUM> may have a length of from about <NUM> to about <NUM>, preferably about <NUM> to about <NUM>, more preferably about <NUM>. In at least one implementation, the inner section <NUM> may have a diameter of from about <NUM> to about <NUM> or greater. For example, the inner section <NUM> may have a diameter of from about <NUM>, about <NUM>, about <NUM>, about <NUM>, or about <NUM> to about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, or greater. In another example, the inner section <NUM> may have a diameter of from about <NUM> to about <NUM>, about <NUM> to about <NUM>, about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM> to about <NUM>. In a preferred implementation, the inner section <NUM> may have a diameter of from about <NUM> to about <NUM>, preferably about <NUM> to about <NUM>, more preferably about <NUM>.

The outer sections <NUM>, <NUM> of the flowpath <NUM> are fluidly coupled with the inner section <NUM> and configured to receive the sample or effluent therefrom. The first and second outer sections <NUM>, <NUM> are frustoconical such that a cross-sectional area at a respective first end portion or inlet <NUM>, <NUM> thereof is relatively less than a cross-sectional area at a respective second end portion or outlet <NUM>, <NUM> thereof. The first and second outer sections <NUM>, <NUM> are both frustoconical, where the respective first end portions or inlets <NUM>, <NUM> are configured to receive the sample from the inner section <NUM>, and the respective second end portions or outlets <NUM>, <NUM> may be configured to deliver the sample to a waste line <NUM> (see <FIG>).

The inner surface <NUM> of the body <NUM> may at least partially define respective taper angles (θ<NUM>, θ<NUM>) of the first outer section <NUM> and the second outer section <NUM>. For example, as illustrated in <FIG>, the portion of the inner surface <NUM> defining or forming the first outer section <NUM> of the flowpath <NUM> and the centerline <NUM> of the flowpath <NUM> may define the respective taper angle (θ<NUM>) of the first outer section <NUM>. In another example, the portion of the inner surface <NUM> defining or forming the second outer section <NUM> of the flowpath <NUM> and the centerline <NUM> of the flowpath <NUM> may define the respective taper angle (θ<NUM>) of the second outer section <NUM>. The first and second outer sections <NUM>, <NUM> may have any taper angles (θ<NUM>, θ<NUM>) capable of or configured to allow the LSD <NUM> and the detectors <NUM>, <NUM>, <NUM> thereof to receive scattered light at any desired angle. While <FIG> illustrates the taper angles (θ<NUM>, θ<NUM>) of the first and second outer sections <NUM>, <NUM> to be relatively equal to one another, it should be appreciated that one of the taper angles (θ<NUM>, θ<NUM>) may be relatively greater than the other. It should further be appreciated that than any one or more attributes (e.g., length, taper angle, diameter, shape, size, etc.) of the first and second outer sections <NUM>, <NUM> may be different. In a preferred implementation, the attributes (e.g., length, taper angle, diameter, shape, size, etc.) of the first outer section <NUM> and the second outer section <NUM> are the same or substantially the same.

Each of the outer sections <NUM>, <NUM> may be fluidly coupled with the waste line <NUM>. For example, as illustrated in <FIG> and <FIG>, the body <NUM> may define a first outlet <NUM> and a second outlet <NUM> extending therethrough and configured to fluidly couple the first outer section <NUM> and the second outer section <NUM> with the waste line <NUM> via a first outlet line <NUM> and a second outlet line <NUM>, respectively. As further illustrated in <FIG>, the first and second outlets <NUM>, <NUM> may be fluidly coupled with the respective second end portions <NUM>, <NUM> of the outer sections <NUM>, <NUM>. It should be appreciated that the orientation (e.g., circumferential orientation) or location of the inlet <NUM> and the first and second outlets <NUM>, <NUM> may vary. For example, the inlet <NUM> may be circumferentially aligned with at least one of the first and second outlets <NUM>, <NUM>. In another example, the inlet <NUM> may be circumferentially offset from at least one of the first and second outlets <NUM>, <NUM>. In yet another example, the first and second outlets <NUM>, <NUM> may be circumferentially aligned with one another or circumferentially offset from one another.

As illustrated in <FIG>, the body <NUM> of the sample cell <NUM> may define an aperture <NUM> extending through at least a portion thereof, and configured to allow light (e.g., scattered light) from the inner section <NUM> to be directed or transmitted to the third detector <NUM>. The aperture <NUM> may be sealed with an optically transparent material <NUM>, such as a quartz crystal, to thereby allow the light from the inner section <NUM> to be directed to the third detector <NUM>. In an exemplary implementation, illustrated in <FIG> and <FIG>, the optically transparent material <NUM> may be shaped to refract a portion of the light towards the third detector <NUM>. For example, the optically transparent material <NUM> may be the sixth lens (e.g., a ball lens) configured to seal the aperture <NUM> and at least partially refract the light towards the third detector <NUM>.

The body <NUM> may include or be fabricated from any suitable material. The body <NUM> may be configured such that the inner surface <NUM> thereof attenuates the reflection of light. For example, the body <NUM> may be fabricated from a non-reflective material. In another example, the body <NUM> may be at least partially fabricated from a reflective material and at least partially coated with a non-reflective material. In at least one implementation, the sample cell <NUM> may be fabricated from quartz, such as black quartz. In an exemplary implementation, the body <NUM> may include or be fabricated from a polymer. Illustrative polymers may be or include, but are not limited to, polyolefin-based polymers, acryl-based polymers, polyurethane-based polymers, ether-based polymers, polyester-based polymers, polyamide-based polymers, formaldehyde-based polymers, silicon-based polymers, any copolymers thereof, or any combination thereof. For example, the polymers may include, but are not limited to, poly(ether ether ketone) (PEEK), TORLON®, polyamide-imides, polyethylene (PE), polyvinyl fluoride (PVF), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polyvinylidene chloride (PVDC), polychlorotrifluoroethylene (PCTFE), polytetrafluoroethylene (PTFE), polypropylene (PP), poly(<NUM>-butene), poly(<NUM>-methylpentene), polystyrene, polyvinyl pyridine, polybutadiene, polyisoprene, polychloroprene, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene terpolymer, ethylene-methacrylic acid copolymer, styrene-butadiene rubber, tetrafluoroethylene copolymer, polyacrylate, polymethacrylate, polyacrylamide, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl ether, polyvinylpyrrolidone, polyvinylcarbazole, polyurethane, polyacetal, polyethylene glycol, polypropylene glycol, epoxy resins, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polydihydroxymethylcyclohexyl terephthalate, cellulose esters, polycarbonate, polyamide, polyimide, any copolymers thereof, or any combination thereof. The polymers may be or include, but are not limited to, elastomers or elastomeric materials, synthetic rubber, or the like. Illustrative elastomeric materials and synthetic rubbers may include, but are not limited to, VITON®, nitrile, polybutadiene, acrylonitrile, polyisoprene, neoprene, butyl rubber, chloroprene, polysiloxane, styrene-butadiene rubber, hydrin rubber, silicone rubber, ethylene-propylene-diene terpolymers, any copolymers thereof, or any combination thereof.

In an exemplary operation of the LSD <NUM>, with continued reference to <FIG>, the sample source <NUM> (e.g., a liquid chromatograph including a gel permeation chromatography column) may inject or direct the sample or effluent (e.g., dilute polymer solution) to and through the flowpath <NUM> of the sample cell <NUM> via line <NUM> and the inlet <NUM>. As illustrated in <FIG>, the sample from the sample source <NUM> may be directed toward a center or middle of the flowpath <NUM> or the inner section <NUM> of the sample cell <NUM>. As the sample flows to the center of the inner section <NUM>, the flow of the of sample may split such that a first portion of the sample flows towards the first outer section <NUM>, and a second portion of the sample flows towards the second outer section <NUM>. The portions of the sample in the first and second outer sections <NUM>, <NUM> may then be directed out of the sample cell <NUM> and to the waste line <NUM> via the first and second outlets <NUM>, <NUM> and the first and second outlet lines <NUM>, <NUM>, respectively.

The rate of flow of the sample through the first outer section <NUM> and the second outer section <NUM> may be modified or adjusted (i.e., increased or decreased) by adjusting the respective lengths of the first outlet line <NUM> and the second outlet line <NUM>. In at least one implementation, a rate of flow of the first and second portions of the sample through the first and second outer sections <NUM>, <NUM> may be the same or substantially the same. For example, the rate of flow of the first portion of the sample through the first outer section <NUM> is the same or substantially the same as the rate of flow of the second portion of the sample through the second outer section <NUM>. In another implementation, the rate of flow of the first and second portions of the sample through the first and second outer sections <NUM>, <NUM> may be different. It should be appreciated, however, that a time correction may be applied if the rate of flow is different through the first and second outer sections <NUM>, <NUM>.

As the sample flows through the flowpath <NUM> of the sample cell <NUM>, the laser <NUM> may emit the beam of light <NUM> along and through the centerline <NUM> of the flowpath <NUM> via the bore <NUM> of the second mirror <NUM>. In at least one implementation, illustrated in <FIG>, the beam of light <NUM> may be transmitted through the third lens <NUM>, which may at least partially focus the beam of light <NUM> along the centerline <NUM> of the flowpath <NUM>. In another implementation, the third lens <NUM> may be omitted. In at least one implementation, an optional screen or diaphragm <NUM> may be disposed between the laser <NUM> and the sample cell <NUM>, and configured to "cleanup," segregate, or otherwise filter stray light (e.g., halo of light) from the beam of light <NUM>. For example, the diaphragm <NUM> may define a hole or aperture (e.g., adjustable aperture/iris) capable of or configured to filter out stray light from the beam of light <NUM>.

At least a portion of the beam of light <NUM> may travel or be transmitted from the laser <NUM> to and through the sample cell <NUM>, the first lens <NUM>, the bore <NUM> of the second mirror <NUM>, and/or an optional diaphragm <NUM>. For example, at least a portion of the beam of light <NUM> may be transmitted unhindered or without interacting with any of the analytes in the sample from the laser <NUM> to and through the sample cell <NUM>, the first lens <NUM>, the bore <NUM> of the second mirror <NUM>, and/or the optional diaphragm <NUM>. The remaining portion of the beam of light <NUM> transmitted through the flowpath <NUM> may interact or otherwise contact analytes suspended, dispersed, or otherwise disposed in the sample and/or flowing through the sample cell <NUM>.

The contact between the beam of light <NUM> and the analytes in the sample may generate or induce scattered light or analyte scattered beams <NUM>, <NUM>, <NUM> (see <FIG> and <FIG>). For example, contact between the beam of light <NUM> and the analytes contained in the sample or flowing through the flowpath <NUM> of the sample cell <NUM> may generate forward and back analyte scattered beams <NUM>, <NUM>. In another example, contact between the beam of light <NUM> and the analytes contained in the sample or flowing through the flowpath <NUM> of the sample cell <NUM> may generate right angle scattered beams <NUM> in a direction generally perpendicular to the beam of light <NUM>.

It should be appreciated that the flow of the sample to the center of the flowpath <NUM> via the inlet <NUM> allows the sample to interact immediately with the beam of light <NUM>, thereby minimizing peak broadening. For example, flowing the sample directly to the center of the flowpath <NUM> allows the sample to interact with the beam of light <NUM> without flowing through at least half the length or volume of the sample cell <NUM> (e.g., in a lateral or axial direction) and the flowpath <NUM> thereof. Flowing the sample directly to the center of the flowpath <NUM> also minimizes the amount of time necessary for the sample to interact with the beam of light <NUM> and generate the analyte scattered beams <NUM>, <NUM>, <NUM>. It should further be appreciated that one or more components of the LSD <NUM> are configured such that only light scattered from the center of the flowpath <NUM> are collected by the detectors <NUM>, <NUM>, <NUM>. For example, at least one of the first lens <NUM>, the first mirror, and the fourth lens <NUM> may be configured to segregate forward light scattering <NUM> that originates from the center of the flowpath <NUM> from forward light scattering <NUM> that originates from other regions of the flowpath <NUM>, such that the first detector <NUM> only receives forward light scattering <NUM> that originates from the center of the flowpath <NUM>. Similarly, at least one of the second lens <NUM>, the second mirror <NUM>, and the fifth lens <NUM> may be configured to segregate back light scattering <NUM> that originates from the center of the flowpath <NUM> from back light scattering <NUM> that originates from other regions of the flowpath <NUM>, such that the second detector <NUM> only receives back light scattering <NUM> that originates from the center of the flowpath <NUM>.

As illustrated in <FIG>, the forward analyte scattered beams or forward scattered light <NUM> may be directed towards the first detector <NUM> via the first lens <NUM>, the first mirror <NUM>, and the fourth lens <NUM>. At least a portion of the forward scattered light <NUM> may be at least partially refracted by the convex surface defined along the first end portion <NUM> of the first lens <NUM>. As illustrated in <FIG>, the forward scattered light <NUM> may be refracted by the convex surface toward the first mirror <NUM>, and the first mirror <NUM> may reflect the forward scattered light <NUM> toward the first detector <NUM> via the fourth lens <NUM>. The fourth lens <NUM> may collect the forward scattered light <NUM>, and direct and/or focus the forward scattered light <NUM> toward the first detector <NUM>.

The forward scattered light <NUM> may be scattered at varying angles of from greater than <NUM>° to less than <NUM>°, relative to the beam of light <NUM> emitted from the laser <NUM>. For example, the forward scattered light <NUM> may be scattered at any angle of from greater than <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or about <NUM>° to about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or less than <NUM>°. In another example, the forward scattered light <NUM> may be scattered at any angle of from about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or about <NUM>° to about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or about <NUM>°, relative to the beam of light <NUM> emitted from the laser <NUM>. In yet another example, the forward scattered light <NUM> may be scattered at an angle of from about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, or about <NUM>° to about <NUM>°. It should be appreciated that the LSD <NUM> and any component thereof may be configured to receive the forward scattered light <NUM> scattered at any angle greater than <NUM>° and less than <NUM>°. For example, any one or more attributes (e.g., shape, location, orientation, etc.) of the first detector <NUM>, the first lens <NUM>, the first mirror <NUM>, the fourth lens <NUM>, and/or any additional optional diaphragms may be adjusted, modified, or otherwise configured such that the first detector <NUM> may receive any of the forward scattered light <NUM>. In a preferred implementation, the LSD <NUM> and the first detector <NUM> thereof is configured to receive or collect the forward scattered light <NUM> at an angle of from about <NUM>° to about <NUM>°, preferably about <NUM>° to about <NUM>°, and more preferably at an angle of about <NUM>°, relative to the beam of light <NUM>.

As illustrated in <FIG>, the back analyte scattered beams or back scattered light <NUM> may be directed towards the second detector <NUM> via the second lens <NUM>, the second mirror <NUM>, and the fifth lens <NUM>. At least a portion of the back scattered light <NUM> may be at least partially refracted by the convex surface of the second lens <NUM>. As illustrated in <FIG>, the back scattered light <NUM> may be refracted by the convex surface toward the second mirror <NUM>, and the second mirror <NUM> may reflect the back scattered light <NUM> toward the second detector <NUM> via the fifth lens <NUM>. The fifth lens <NUM> may collect the back scattered light <NUM>, and direct and/or focus the back scattered light <NUM> toward the second detector <NUM>.

The back scattered light <NUM> may be scattered at varying angles of from greater than <NUM>° to less than <NUM>°, relative to the beam of light <NUM> emitted from the laser <NUM>. For example, the back scattered light <NUM> may be scattered at any angle of from greater than <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or about <NUM>° to about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or less than <NUM>°. In another example, the back scattered light <NUM> may be scattered at any angle of from about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or about <NUM>° to about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, or about <NUM>°, relative to the beam of light <NUM> emitted from the laser <NUM>. In yet another example, the back scattered light <NUM> may be scattered at an angle of from about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, about <NUM>° to about <NUM>°, or about <NUM>° to about <NUM>°. It should be appreciated that the LSD <NUM> and any component thereof may be configured to receive the back scattered light <NUM> scattered at any angle greater than <NUM>° and less than <NUM>°. For example, any one or more attributes (e.g., shape, location, orientation, etc.) of the second detector <NUM>, the second lens <NUM>, the second mirror <NUM>, the fifth lens <NUM>, and/or any additional optional diaphragms may be adjusted, modified, or otherwise configured such that the second detector <NUM> may receive any of the back scattered light <NUM>. In a preferred implementation, the LSD <NUM> and the second detector <NUM> thereof is configured to receive or collect the back scattered light <NUM> at an angle of from about <NUM>° to about <NUM>°, preferably about <NUM>° to about <NUM>°, and more preferably at an angle of about <NUM>°, relative to the beam of light <NUM>.

As illustrated in <FIG>, the right angle analyte scattered beams or right angle scattered light <NUM> may be directed towards the third detector <NUM> via the aperture <NUM> extending between the third detector <NUM> and the inner section <NUM> of the flowpath <NUM>. In at least one implementation, the third detector <NUM> may be disposed in the aperture <NUM> adjacent the inner section <NUM>. In another implementation, illustrated in <FIG>, the optically transparent material <NUM> may be disposed in the aperture <NUM> to seal the inner section <NUM> of the flowpath <NUM>. The optically transparent material <NUM> may be any suitable material capable of allowing the right angle scattered light <NUM> to be transmitted to the third detector <NUM>. The optically transparent material <NUM> may be shaped to refract at least a portion of the right angle scattered light <NUM> toward the third detector <NUM>. For example, as previously discussed, the optically transparent material <NUM> may be a ball lens shaped to refract the right angle scattered light <NUM> toward the third detector <NUM>.

Claim 1:
A sample cell (<NUM>) for a light scattering detector, comprising:
a body (<NUM>) defining a flowpath (<NUM>) extending axially therethrough, the flowpath comprising an inner section (<NUM>) interposed between a first outer section (<NUM>) and a second outer section (<NUM>),
wherein the first outer section is frustoconical, and a first end portion (<NUM>) of the first outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively less than a cross-sectional area at a second end portion (<NUM>) thereof,
wherein the second outer section is frustoconical, and a first end portion (<NUM>) of the second outer section is in direct fluid communication with the inner section and has a cross-sectional area relatively less than a cross-sectional area at a second end portion (<NUM>) thereof, and
wherein the body further defines an inlet (<NUM>) in direct fluid communication with the inner section and configured to direct a sample to the inner section of the flowpath,
characterised in that:
the inner section (<NUM>) is cylindrical and has a length extending between the first (<NUM>) and second (<NUM>) outer sections of <NUM> or greater.