阅读说明：本技术 带腔室隔膜 (Diaphragm with chamber ) 是由 C.A.卡里斯勒 M.M.马雷 D.L.琼斯 E.J.海尼 D.S.胡巴德 于 2018-12-14 设计创作，主要内容包括：一种隔膜,其沿着隔膜的中心轴线包含至少一个内部腔室。该腔室提供了释放空间,当针穿过隔膜时,隔膜的密封部分可变形到该释放空间中。腔室的结合减少了隔膜和针之间的表面积接触和摩擦,从而减少了隔膜的撕裂并减少了研磨产生的颗粒物。(A septum comprising at least one internal chamber along a central axis of the septum. The chamber provides a relief space into which the sealing portion of the septum may deform as the needle passes through the septum. The incorporation of the chamber reduces surface area contact and friction between the septum and the needle, thereby reducing septum tearing and reducing particulate generation from abrasion.)

1. A septum, comprising:

a body formed of a resilient elastomeric material, the body having a top surface, a bottom surface, and at least one side extending between the top surface and the bottom surface, the body including a central axis; and

at least one internal chamber within the body, the central axis extending through the chamber.

2. The septum of claim 1, further comprising an upper seal between the at least one chamber and the top surface and a bottom seal between the at least one chamber and the bottom surface.

3. The septum of claim 2, wherein the upper seal has a thickness in a range of about 0.1mm to about 2mm, and wherein the lower seal has a thickness in a range of about 0.1mm to about 2 mm.

4. A septum as defined in claim 1, wherein the diameter of the chamber is in a range of about 0.06mm to 13 mm.

5. The septum of claim 1, wherein the body comprises a first portion and a second portion, the second portion comprising a recess sized and shaped to receive at least a portion of the first portion.

6. A diaphragm according to claim 5, wherein the first portion is cylindrical and wherein the recess is sized and shaped to receive at least a portion of the cylindrical first portion.

7. A diaphragm according to claim 6, wherein the first portion and the recess are in tongue and groove co-operative engagement.

8. A septum as defined in claim 5, wherein the chamber is formed between the first portion and the second portion.

9. The septum of claim 5, wherein the first portion is formed from a first elastomeric material, wherein the second portion is formed from a second elastomeric material, and wherein the first and second elastomeric materials have different mechanical properties.

10. The septum of claim 1, further comprising an upper cavity formed in the top surface.

11. The septum of claim 1, further comprising a lower cavity formed in the bottom surface.

12. The septum of claim 1, further comprising an upper chamber formed in the top surface and a lower chamber formed in the bottom surface, the central axis extending continuously through the upper chamber, and lower chamber.

13. A septum as defined in claim 1, wherein the septum is pre-pierced along the central axis.

14. A method of using a chambered septum, comprising:

providing a separator having: a body formed of a resilient elastomeric material, the body having a top surface, a bottom surface, at least one side extending between the top surface and the bottom surface; at least one internal chamber within the body; an upper seal between at least one chamber and the top surface; a bottom seal between the at least one chamber and the bottom surface; and a central axis extending through the chamber;

inserting the bottom surface into a gas chromatography injection port; and

the needle is inserted into the upper seal, the interior chamber, and the bottom seal in sequence along the central axis.

15. The method of claim 14, wherein the first and second light sources are selected from the group consisting of,

wherein the top surface comprises an upper cavity;

wherein the central axis extends through the upper chamber; and

wherein the step of inserting the needle comprises inserting the needle into the upper chamber, the upper seal, the interior chamber, and the bottom seal in that order along the central axis.

16. The method of claim 14, wherein the first and second light sources are selected from the group consisting of,

wherein the bottom surface includes a lower cavity;

wherein the central axis extends through the lower chamber; and

wherein the step of inserting the needle comprises inserting the needle into the upper seal, the interior chamber, the bottom seal, and the lower chamber in that order along the central axis.

17. The method of claim 14, wherein the first and second light sources are selected from the group consisting of,

wherein the top surface comprises an upper cavity;

wherein the bottom surface includes a lower cavity;

wherein the central axis extends through the lower chamber and the lower chamber; and

wherein the step of inserting the needle comprises inserting the needle into the upper chamber, the upper seal, the interior chamber, the bottom seal, and the lower chamber in that order along the central axis.

18. The method of claim 14, further comprising retracting the needle after insertion.

19. The method of claim 18, wherein,

The step of retracting the needle includes retracting the needle along the central axis sequentially through the bottom seal, the interior chamber, and the upper seal.

20. The method of claim 18, wherein the force required to insert and withdraw the needle does not exceed 4N.

Technical Field

The septum contains at least one internal chamber along a central axis of the septum. The chamber provides a relief space into which the sealing portion of the septum may deform as the needle passes through the septum. The incorporation of the chamber reduces surface area contact and friction between the septum and the needle, thereby reducing septum tearing and reducing particulate generation from abrasion.

Background

Gas chromatography ("GC") is a widely used analytical technique with high sensitivity. Typically, a liquid sample is injected through an elastomeric seal (a "septum" typically made of silicone rubber or other elastomer) into a hot injection port where the sample is vaporized in an inert gas stream and the components are separated as the gas stream is swept through a chromatography column. The components eluted from the column are detected with a high sensitivity detector. The inertness and reproducibility of the injectate is critical to maintaining a high level of detection accuracy.

The primary purpose of the membrane is to seal against carrier gas leakage so that the sample is properly eluted through the column. Ideally, the septum must act as an effective hermetic seal for up to several hundred injections, each requiring a needle to pierce the thickness of the septum. The diaphragm may be exposed to temperatures ranging from ambient to nearly 300 c and may be exposed to pressures up to 100 psi.

GC diaphragms currently used in laboratories largely meet the requirements for reliable sealing and essentially follow a single basic design: a solid disc or plug of polymeric material through which the needle is pierced and into which the sample is injected. While this basic design does work effectively as a seal, one problem that has not heretofore been addressed is the inadvertent introduction of contaminating particles into the GC inlet. Repeated needle penetration through the septum can wear and roughen the needle, causing particulate septum material and metal fines to be brushed from the needle into the inlet. The membrane material adds volatile contaminants on the chromatographic baseline that appear as peaks interfering with the desired peaks from the sample components, and both the membrane material and the metal fines may act as adsorbents or catalysts, removing or degrading the components in the inlet before they can be detected.

To reduce particle generation in standard septums, it is well known in the art that septums should not be over-tightened when installed to avoid over-compression in the inlet, increased friction between the needle and the septum, and increased likelihood of particle generation. Over time, innovations to this standard design have been introduced to improve performance and reduce particle generation. One example is the addition of a chamfered, generally conical cavity on the outer surface of the septum to help confine the needle to a path through the septum. Another example is pre-piercing the septum along the intended path of the needle to minimize "coring" (the creation of particles of septum material) in the first few injections. It is well known that finer needles and needles without sharp tips reduce particle generation. However, thinner needles may also bend more frequently than thicker needles, causing other problems. Although these various techniques can reduce the generation of contaminating particles, the problem has not been satisfactorily solved.

Disclosure of Invention

It is an object of the present invention to reduce contamination in the GC inlet by providing a novel membrane. The septum contains at least one internal chamber along a central axis of the septum. The chamber provides a relief space into which the sealing portion of the septum may deform as the needle passes through the septum. The incorporation of the chamber reduces surface area contact and friction between the septum and the needle, thereby reducing septum tearing and reducing particulate generation from abrasion. The diaphragm portions above and below the chamber act as a relatively thin top seal and a separate relatively thin bottom seal.

In contrast, in a typical septum, the entire body of the septum acts as a single, relatively thick seal.

This summary is provided to introduce a selection of concepts that are further described in the detailed description and the drawings contained herein. This summary is not intended to identify any essential or essential features of the claimed subject matter. Some or all of the described features may be present in the respective independent or dependent claims, but should not be construed as limiting unless expressly recited in a particular claim. Each embodiment described herein is not necessarily intended to address each and every object described herein, and each embodiment does not necessarily include every feature described. Other forms, embodiments, objects, advantages, benefits, features, and aspects of the present invention will become apparent to one skilled in the art from the detailed description and drawings contained herein. Moreover, the various apparatus and methods described in this summary section, as well as elsewhere in this application, can be expressed in a number of different combinations and sub-combinations. All such useful, novel, and inventive combinations and sub-combinations are contemplated herein, and it is to be understood that express expressions of each of these combinations are not necessary.

Drawings

The invention will be better understood by reference to the following description taken in conjunction with the accompanying drawings.

Figure 1 shows a cross-sectional view of a standard disk-shaped septum cut in half along its central axis after multiple injections.

Figure 2A depicts a perspective view of a first embodiment of a septum, wherein a first portion and a second portion of the septum are in a spaced apart relationship.

Fig. 2B depicts a perspective view of the first embodiment with the first portion installed within the second portion.

Fig. 2C shows a cross-sectional view along line a-a of the first embodiment.

Figure 3A depicts a perspective view of a second embodiment of a septum, wherein a first portion and a second portion of the septum are in a spaced apart relationship.

Fig. 3B depicts a perspective view of the second embodiment, with the first portion installed within the second portion.

Fig. 3C shows a cross-sectional view along the line B-B of the second embodiment.

Figure 4A shows a cross-sectional view of a standard plug-shaped septum cut in half along its central axis.

Figure 4B is a graph of force (Y-axis) versus time (X-axis) for a needle insertion (positive force) and retraction (negative force) through the septum shown in figure 4A over a duration of 2500 seconds (approximately 275 injection cycles).

Figure 5A shows a cross-sectional view of a chambered stopper-shaped septum cut in half along its central axis.

Figure 5B is a graph of force (Y-axis) versus time (X-axis) for needle insertion (positive force) and retraction (negative force) through the septum shown in figure 5A over a duration of 2500 seconds (approximately 275 injection cycles).

FIG. 6A depicts a cross-sectional view of a standard, pre-pierced disk-shaped septum cut in half along its central axis.

Figure 6B depicts a cross-sectional view of a standard, pre-pierced disk-shaped septum cut in half along its central axis after being subjected to 1000 injections.

FIG. 7A depicts a cross-sectional view of a chambered, disk-shaped septum cut in half along its central axis.

Figure 7B depicts a cross-sectional view of a chambered, disk-shaped septum cut in half along its central axis after being subjected to 1000 injections.

Figure 8A is a photograph of a GC injection port liner after 1000 injections through the septum in figure 6B.

Figure 8B is a photograph of a GC injection port liner after 1000 injections through the septum in figure 7B.

Figure 9A shows a cross-sectional view of a standard plug-shaped septum cut in half along its central axis.

Figure 9B shows a cross-sectional view of a standard stopper-shaped septum cut in half along its central axis after being subjected to 500 injections. FIG. 10A depicts a cross-sectional view of a chambered, plug-shaped septum cut in half along its central axis.

Figure 10B depicts a cross-sectional view of a chambered, plug-shaped septum cut in half along its central axis after being subjected to 500 injections.

Figure 11A is a photograph of a GC injection port liner after 500 injections through the septum in figure 9B.

Fig. 11B is a photograph of a GC injection port liner after 500 injections through the septum in fig. 10B.

Figure 12A depicts a perspective view of a third embodiment of a septum, wherein a first portion and a second portion of the septum are in a spaced apart relationship.

Fig. 12B depicts a perspective view of the third embodiment, with the first portion installed within the second portion.

Fig. 12C shows a cross-sectional view along line a-a of the third embodiment.

Figure 13A depicts a perspective view of a fourth embodiment of a septum, wherein a first portion and a second portion of the septum are in a spaced apart relationship.

Fig. 13B depicts a perspective view of the fourth embodiment, with the first portion installed within the second portion.

Fig. 13C shows a cross-sectional view along line a-a of the fourth embodiment.

Figure 14A depicts a perspective view of a fifth embodiment of a septum, wherein a first portion and a second portion of the septum are in a spaced apart relationship.

Fig. 14B depicts a perspective view of the fifth embodiment, with the first portion installed within the second portion.

Fig. 14C shows a cross-sectional view along line a-a of the fifth embodiment.

Detailed Description

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to selected embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended; any alterations and further modifications in the described or illustrated embodiments, and any further applications of the principles of the invention as illustrated herein are contemplated as would normally occur to one skilled in the art to which the invention relates. At least one embodiment of the invention is shown in detail, although it will be apparent to those skilled in the art that some features or some combinations of features may not be shown for the sake of clarity.

Any reference herein to "the invention" is a reference to a series of embodiments of the invention and no single embodiment includes all features that are necessarily included in all embodiments, unless so stated. Moreover, although reference may have been made to "advantages" provided by some embodiments of the invention, other embodiments may not include those same advantages, or may include different advantages. Any advantages described herein should not be construed as limiting any claim.

Specific quantities (spatial dimensions, dimensionless parameters, etc.) may be used explicitly or implicitly herein and, unless otherwise indicated, are provided by way of example only and are approximations. Unless otherwise indicated, any amount referred to as "about" a given value is defined as within 5% of the value (e.g., "about 1.0 mm" means a range of 0.95mm to 1.05 mm; "about 1.0mm to 2.0 mm" means a range of 0.95mm to 2.1 mm). Unless otherwise stated, discussion of a particular composition of matter (if any) is provided as an example only, and does not limit the applicability of other compositions of matter, particularly other matter having similar properties. The terms top and bottom as used herein refer to the orientation of the septum as shown in the drawings and to the movement of a needle inserted into the top of the septum, through the septum and exposed from the bottom. It should be understood that the septum may be mounted on the fitting in a variety of orientations such that the insertion point "top" may be oriented laterally, angularly, or upside down.

Particulate contamination in the GC typically results from tearing of the septum along its central axis, which is the typical path of the needle through the septum during injection. FIG. 1 shows a standard disk-shaped septum 10 that has been cut in half along its central axis 12 to expose the path of the needle, as is generally known in the art. The two halves are shown with the bottom surfaces 14 adjacent one another and the top surfaces 16 opposite one another, the top surfaces being identified by the chamfered guides 18.

It is evident that during use, the silicone rubber sheet has worn away from the interior of the diaphragm 10 along the central axis 12. This failure mode-material grinding and tearing-is well known for silicone rubber. This grinding action occurs inside the septum 10 due to compressive and dynamic friction forces as the needle enters the septum. The septum 10 is primarily contained within the GC instrument assembly during use, and thus the compressive stress on the septum 10 increases with the volume of the needle received into the septum 10. The portions of the septum 10 closest to the top surface 16 and bottom surface 14 are less abrasive because the septum deforms into the open space when the needle passes through, thereby reducing tearing of the material. However, inside the diaphragm 10, the abrasive force exceeds the strength and fatigue limit of the silicone rubber, causing the diaphragm 10 to tear into pieces.

Fig. 2A to 2C depict a diaphragm 110 according to a first embodiment of the present invention. In this first embodiment, the diaphragm 110 is generally disc-shaped, having a top surface 116, a bottom surface 114, and sides 120 extending between the top surface 116 and the bottom surface 114. The septum 110 has a diameter of about 10.82mm and a thickness of about 3.17 mm. The central axis 112 extends vertically through the center of the diaphragm 110. In this first embodiment, top surface 116 includes a tapered upper cavity 118 centered about central axis 112, upper cavity 118 having a depth of about 0.89mm and a diameter of about 1.27 mm. Upper lumen 118 is used to guide a needle inserted into top surface 116 therethrough along central axis 112.

As shown in fig. 2C, the septum 110 includes a hollow interior chamber 124 that is separated from the top surface 116, the bottom surface 114, the sides 120, and the upper cavity 118. In some embodiments, the diameter of the chamber 124 is in the range of about 1.0mm to about 3.0mm, and the height is in the range of about 0.9mm to about 1.25 mm. The portion of the septum 110 between the chamber 124 and the lowest point of the conical upper chamber 118 is referred to as the top seal 126 and has a thickness of approximately 0.65 mm. The portion of the diaphragm 110 between the chamber 124 and the bottom surface 114 is referred to as a bottom seal 128 and has a thickness of about 0.65 mm. In other embodiments, the top seal and the bottom seal have a thickness greater than 0.0mm and no greater than 2.0 mm. In combination with this and other disclosed embodiments, the top and bottom seals have a thickness in the range of 0.3mm to 1.2mm or in the range of 0.5mm to 0.8 mm. It should be readily understood that the foregoing dimensions are provided for exemplary purposes only, and that larger and smaller diaphragms are contemplated.

In some embodiments, the diaphragm 110 is formed in two parts to facilitate manufacturing. The larger second portion 130 includes a generally cylindrical recess 132 sized and shaped to receive a generally cylindrical first portion 134, with the interior chamber 124 formed between the first and second portions 134, 130. In the depicted embodiment, the first portion 134 includes a raised ridge 136 extending around the circumference of the first portion 134, and the second portion 130 includes a corresponding groove 138 extending around the circumference of the recess 132, such that the first portion 134 and the second portion 130 engage each other via a tongue and groove fit. In alternative embodiments, the first portion 134 and the second portion 130 may be joined via a retaining ring, a friction fit, an adhesive, a chemical bond, or other means known in the art.

Fig. 3A-3C depict a diaphragm 210 according to a second embodiment of the present invention. In this second embodiment, the diaphragm is of a "plug" design, generally cylindrical, having a larger diameter upper portion 211 and a smaller diameter lower portion 213. The diaphragm includes a top surface 216, a bottom surface 214, and sides 220 extending between the top surface 216 and the bottom surface 214. The upper portion 211 has a diameter of about 7.10mm and a thickness of about 3.04 mm. Lower portion 213 has a diameter of about 5.62mm and a thickness of about 4.25 mm. A central axis 212 extends vertically through the center of the diaphragm 210. The top surface 216 includes a cylindrical upper cavity 218 centered about the central axis 212, the cylindrical cavity 218 tapering to a point thereon. The upper chamber 218 has a diameter of about 1.52mm and a depth of about 3.04 mm. The upper cavity 218 serves to guide a needle inserted into the top surface 216 therethrough along the central axis 212. The bottom surface 214 includes a cylindrical lower cavity 240 centered about the central axis 212. The lower chamber 240 has a diameter of about 1.25mm and a depth of about 1.0 mm.

As shown in fig. 3C, the diaphragm 210 includes an interior chamber 224 spaced apart from the top surface 216, the bottom surface 214, the sides 220, the upper chamber 218, and the lower chamber 240. In one embodiment, chamber 224 has a diameter of about 1.25mm and a height of about 1.95 mm. In other embodiments, the diameter of the chamber 224 is in the range of about 1.0mm to 2.0 mm.

The portion of the diaphragm 210 between the chamber 224 and the upper chamber 218 is referred to as a top seal 226 and has a thickness of about 0.65 mm. The portion of the diaphragm 210 between the chamber 224 and the lower cavity 240 is referred to as the bottom seal 228 and has a thickness of about 0.65 mm. It should be readily understood that the foregoing dimensions are provided for exemplary purposes only, and that larger and smaller diaphragms are contemplated.

In some embodiments, the diaphragm 210 is formed in two parts to facilitate manufacturing. The larger second portion 230 includes a generally cylindrical recess 232 sized and shaped to receive a generally cylindrical first portion 234, with the interior chamber 224 formed between the first and second portions 234, 230. In the depicted embodiment, the first portion 234 includes a raised ridge 236 extending around the circumference of the first portion 234, and the second portion 230 includes a corresponding groove 238 extending around the circumference of the recess 232, such that the first portion 234 and the second portion 230 engage each other via a tongue and groove fit. In alternative embodiments, the first portion 234 and the second portion 230 may be joined via a retaining ring, a friction fit, an adhesive, a chemical bond, or other means known in the art.

Experimental evidence indicates that the chambered septum of the present invention reduces the friction on the needle compared to a standard chamberless septum. Referring now to fig. 4A and 5A, each depicts a septum separated along its central axis (4A standard, 5A with chambers). The septum was reassembled and the force required for each puncture was recorded on a test station that simulated approximately 275 needle puncture and retraction injection cycles over the course of 2500 seconds. The test station is equipped with a load cell that is connected to a computer to record the force over a number of cycles. As shown in fig. 4B, a standard diaphragm requires a maximum force in excess of 7N to complete an injection cycle, decreasing over time to about 4N. In contrast, as shown in fig. 5B, the chambered septum need not exceed 4N to complete an injection cycle. This relatively low insertion force allows for the use of a smaller gauge needle (e.g., a 26 gauge needle rather than a 23 gauge needle), which may reduce strain on the septum during insertion and retraction. When used with conventional solid state septums, a 26 gauge needle will bend as shown in fig. 1. Furthermore, the reduced transport and low insertion force of the solid septum material through the chambered septum reduces the accumulation of septum material in the needle tip (also known as needle clogging), which results in an off-center spray pattern.

Experimental evidence also indicates that the chambered septum of the present invention produces less contaminating particulates than a standard, pre-pierced, chamberless septum. Figures 6A and 6B show cross-sectional views of an original standard, pre-pierced, chamberless septum and the like after 1000 injection cycles. Figure 6B shows a distinct septum material that has torn along the central axis during use. Figure 8A shows contaminating membrane particulates in the GC liner after exposure to the 1000 shots in figure 6B. Figures 7A and 7B show cross-sectional views of an original chambered septum and similar septum after 1000 injection cycles. Fig. 7B shows the lower seal being worn, but without tearing off a significant amount of the septum material. Figure 8B shows contaminating membrane particulates in the GC liner after exposure to the 1000 injections in figure 7B. Comparing fig. 8A and 8B, the chambered membrane produced negligible particulate after applying 1000 injection cycles, as opposed to a standard membrane that produced a large amount of particulate.

Fig. 9A and 9B show cross-sectional views of an original, standard, chamberless, plug-type septum and the like after 500 injection cycles. Figure 9B shows a distinct septum material that has torn along the central axis during use. Figure 11A shows dispersed contaminating membrane particles in a GC liner after 500 injection cycles through the membrane shown in figure 9B. Figures 10A and 10B show cross-sectional views of an original, chambered, plug-type septum and the like after 500 injection cycles. Fig. 10B shows no significant damage to the upper and lower seals and no tearing of the septum. Figure 11B shows contaminating diaphragm particulates in the GC liner after 500 injection cycles through the diaphragm shown in figure 10B. Comparing fig. 11A and 11B, the chambered plug-type membrane produced substantially no contaminating particulates after 500 injection cycles of application, as opposed to a standard membrane that produced visible particulates.

Experimental evidence indicates that the injection life (i.e., the number of injections before leakage) of a chambered membrane is longer than that of an equivalent chamberless membrane. Without being bound by theory, it is hypothesized that the relatively thin upper and lower seals may be more free to deform away from the needle than conventional septums, in which substantially the entire thickness of the septum forms the seal.

Also, particles that tear off the septum are less likely to embed in the seal and urge it open. Further, even if particles are embedded in the upper seal or the lower seal, the remaining seal can prevent leakage, thereby providing an anti-protection function that does not exist in the conventional diaphragm.

In side-by-side testing of an 11mm standard diaphragm with an 11mm chambered diaphragm, the chambered diaphragm had a longer useful life before failing (i.e., leaking), as shown in table 1 below.

Table 1: injection life of standard versus chambered membrane conditions: 99psi, 275 deg.C inlet, 3/4 cycles after the first contact, a two gauge Gold injector, and methanol injection. Leak rates were measured using a flowmeter that provided the leak rate (in milliliters per minute) and an electronic leak detector (0-7 lamps are shown as the leak rate increased).

The standard diaphragm failed after about 700 injections, while the chambered diaphragm failed after about 1000 injections.

Fig. 12A to 12C depict a septum 310 according to a third embodiment of the invention. In this third embodiment, the diaphragm 310 is generally disc-shaped, having a top surface 316, a bottom surface 314, and sides 320 extending between the top surface 316 and the bottom surface 314. Septum 310 has a diameter of about 10.82mm and a thickness of about 3.17 mm. A central axis 312 extends vertically through the center of the diaphragm 310. In this third embodiment, the top surface 316 includes a conical upper cavity 318 centered about the central axis 312, the upper cavity 318 having a depth of about 0.89mm and a diameter of about 1.27 mm. The upper cavity 318 serves to guide a needle inserted into the top surface 316 therethrough along the central axis 312. In this third embodiment, the bottom surface 314 includes a lower cavity 319 centered about the central axis 312. In some embodiments, the lower cavity 319 is generally circular in shape with a flat bottom having a depth of about 0.31mm and a diameter of about 1.0mm to about 3.0 mm. In one embodiment, the diameter is about 1.25 mm.

As shown in fig. 12C, the septum 310 includes an internal chamber 324 spaced apart from the top surface 316, the bottom surface 314, the sides 320, the upper chamber 318, and the lower chamber 319. In some embodiments, the chamber 324 has a diameter in the range of about 1.0mm to about 3.0mm and a height of about 0.67 mm. The portion of the diaphragm 310 between the chamber 324 and the lowest point of the conical upper chamber 318 is referred to as the top seal 326 and has a thickness of about 0.65 mm. The portion of the diaphragm 310 between the chamber 324 and the lower cavity 319 is referred to as the bottom seal 328 and has a thickness of about 0.65 mm. It should be readily understood that the foregoing dimensions are provided for exemplary purposes only, and that larger and smaller diaphragms are contemplated.

In some embodiments, the diaphragm 310 is formed in two parts to facilitate manufacturing. The larger second portion 330 includes a generally cylindrical recess 332 sized and shaped to receive a generally cylindrical first portion 334, with the interior chamber 324 formed between the first portion 334 and the second portions 134, 330. In the depicted embodiment, the first portion 334 includes a raised ridge 336 extending around a circumference of the first portion 334, and the second portion 330 includes a corresponding groove 338 extending around a circumference of the recess 332, such that the first portion 334 and the second portion 330 engage each other via a tongue and groove fit. In alternative embodiments, the first portion 334 and the second portion 330 may be joined via a retaining ring, a friction fit, an adhesive, a chemical bond, or other means known in the art.

Figures 13A-13C depict a septum 410 according to a fourth embodiment of the invention. In this fourth embodiment, the diaphragm 410 is generally disc-shaped, having a top surface 416, a bottom surface 414, and sides 420 extending between the top surface 416 and the bottom surface 414. The septum 410 has a diameter of about 10.82mm and a thickness of about 3.17 mm. A central axis 412 extends vertically through the center of the diaphragm 410. In this fourth embodiment, the top surface 416 includes a flat bottom upper cavity 418 centered about the central axis 412, the upper cavity 418 having a depth of about 0.62mm and a diameter in the range of about 1.0mm to 3.0 mm.

The upper cavity 418 serves to guide the passage of a needle inserted into the top surface 416 along the central axis 412. In this fourth embodiment, the bottom surface 416 includes a lower cylindrical cavity 419 centered about the central axis 412. In some embodiments, lower cavity 419 is generally circular in shape with a flat bottom having a depth of about 0.31mm and a diameter of about 1.0mm to about 3.0 mm. In one embodiment, the diameter is about 1.25 mm.

Without being bound by theory, this flat bottom design of the upper cavity 418 reduces the surface area contact between the septum 410 and the needle and applies more uniform stress to the septum 410 when inserting and retracting the needle than a tapered chamfered design of the upper cavity 318. However, both designs are advantageous because the tapered chamfer design can more accurately guide the needle along the central axis 312.

As shown in fig. 13C, the septum 410 includes an interior chamber 424 that is spaced apart from the top surface 416, the bottom surface 414, the sides 420, the upper chamber 418, and the lower chamber 419. In some embodiments, chamber 424 has a diameter in the range of about 1.0mm to about 3.0mm and a height of about 1.24 mm. The portion of the diaphragm 410 between the chamber 424 and the upper chamber 418 is referred to as a top seal 426 and has a thickness of about 0.65 mm. The portion of diaphragm 410 between chamber 424 and lower chamber 419 is referred to as bottom seal 428 and has a thickness of about 0.65 mm. It should be readily understood that the foregoing dimensions are provided for exemplary purposes only, and that larger and smaller diaphragms are contemplated.

The septum 410 of this fourth embodiment is substantially similar to the septum 310 of the third embodiment, except for an upper chamber 418 and a chamber 424. The upper chamber 418 has a reduced depth compared to the upper chamber 318 and each has a similar thickness of the top seals 328, 428, resulting in a height of the chamber 424 that is greater than the height of the chamber 324.

In some embodiments, the diaphragm 410 is formed in two parts to facilitate manufacturing. The larger second portion 430 includes a generally cylindrical recess 432 sized and shaped to receive a generally cylindrical first portion 434, with the interior chamber 424 formed between the first portion 434 and the second portions 134, 430. In the depicted embodiment, the first portion 434 includes a raised ridge 436 extending around the circumference of the first portion 434 and the second portion 430 includes a corresponding groove 438 extending around the circumference of the recess 432 such that the first portion 434 and the second portion 430 engage one another with a tongue and groove fit. In alternative embodiments, the first portion 434 and the second portion 430 may be joined via a retaining ring, a friction fit, an adhesive, a chemical bond, or other means known in the art.

Figures 14A-14C depict a septum 510 according to a fifth embodiment of the invention. In this fifth embodiment, the septum is of a "plug" design, being generally cylindrical, having a larger diameter upper portion 511 and a smaller diameter lower portion 513. The diaphragm includes a top surface 516, a bottom surface 514, and a side 220 extending between the top surface 516 and the bottom surface 514. The upper portion 511 has a diameter of about 7.10mm and a thickness of about 3.04 mm. Lower portion 513 has a diameter of about 5.62mm and a thickness of about 4.25 mm. A central axis 512 extends vertically through the center of the diaphragm 510. The top surface 516 includes a cylindrical upper cavity 518 centered about the central axis 512. Although the upper chamber 218 in the diaphragm 210 of the second embodiment tapers to a point, the upper chamber 518 of this fifth embodiment has a substantially flat bottom. The upper chamber 518 has a diameter of about 1.52mm and a depth in the range of about 1.5mm to about 2.7 mm. The upper cavity 518 serves to guide a needle inserted into the top surface 516 through along the central axis 512. The bottom surface 514 includes a cylindrical lower cavity 540 centered about the central axis 512. The lower chamber 540 has a diameter of about 1.25mm and a depth of about 1.0 mm.

As shown in fig. 14C, the diaphragm 510 includes an interior chamber 524 spaced from the top surface 516, the bottom surface 514, the sides 520, the upper chamber 518, and the lower chamber 540. In one embodiment, the chamber 524 is generally mushroom-shaped having a diameter of about 1.52mm at an upper portion thereof and about 1.25mm at a lower portion thereof. The height of the chamber 524 is in the range of 2.0mm to 3.5mm, and in the embodiment shown, the height is about 2.075 mm. The portion of the septum 510 between the chamber 524 and the upper chamber 518 is referred to as a top seal 526 and has a thickness of about 0.65 mm. The portion of the diaphragm 510 between the chamber 524 and the lower chamber 540 is referred to as the bottom seal 528 and has a thickness of about 0.65 mm. It should be readily understood that the foregoing dimensions are provided for exemplary purposes only, and that larger and smaller diaphragms are contemplated.

In some embodiments, septum 510 is formed in two parts to facilitate manufacturing. The larger second portion 530 includes a generally cylindrical recess 532 sized and shaped to receive the generally cylindrical first portion 534, with the internal chamber 524 formed between the first and second portions 534, 134, 530. In the depicted embodiment, first portion 534 includes a ridge 536 that extends around the circumference of first portion 534. The second portion 530 includes a corresponding groove 538 extending around the circumference of the recess 532 such that the first portion 534 and the second portion 530 engage each other by a tongue and groove fit. In alternative embodiments, first portion 534 and second portion 530 may be joined via a retaining ring, friction fit, adhesive, chemical bond, or other means known in the art.

In further embodiments (not shown), the chambered septum of the present invention may include more than one internal chamber. In such an embodiment, the diaphragm would include an upper seal between the upper surface and the first chamber, a middle seal between the first chamber and the second chamber, and a lower seal between the second chamber and the bottom surface. Embodiments having three or more chambers are also contemplated.

In further embodiments, the chambered septum of the present invention may be formed from a single resilient elastomeric material or a combination or mixture of materials. In some embodiments, the first portion may be made of a first elastomeric material and the second portion may be made of a second elastomeric material. The first and second elastomeric materials may have different mechanical properties, such as a first elastomeric material having a first hardness and a second elastomeric material having a second hardness, wherein the first hardness and the second hardness are different. In certain embodiments, the first and second portions may be made of the same elastomeric material, but with different additives to provide different mechanical properties.

In further embodiments, including any of the first through fifth embodiments described above, the chambered septum may optionally be pre-pierced along the central axis.

Various aspects of different embodiments of the present disclosure are represented in paragraphs X1 and X2, as follows:

x1, one embodiment of the present disclosure includes a septum comprising a body formed of a resilient elastomeric material having a top surface, a bottom surface, and at least one side extending between the top surface and the bottom surface, the body including a central axis and at least one internal chamber within the body, the central axis extending through the chamber.

X2, another embodiment of the present disclosure includes a method of using a chambered septum, the method comprising:

providing a separator having:

a body formed of a resilient elastomeric material, the body having a top surface, a bottom surface, at least one side extending between the top surface and the bottom surface;

at least one interior chamber within the body;

an upper seal between the at least one chamber and the top surface; a bottom seal between the at least one chamber and the bottom surface; a

And a central axis extending through the chamber;

inserting the bottom surface into a gas chromatography injection port; and

the needle is inserted into the upper seal, the interior chamber, and the bottom seal in sequence along the central axis.

Other embodiments include the features of any of the preceding paragraphs X1 or X2 in combination with one or more of the following aspects:

wherein the septum includes an upper seal between the at least one chamber and the top surface and a bottom seal between the at least one chamber and the bottom surface.

Wherein the upper seal has a thickness in a range of about 0.1mm to about 2 mm.

Wherein the upper seal has a thickness in a range of about 0.3mm to about 1.2 mm.

Wherein the upper seal has a thickness of about 0.65 mm.

Wherein the lower seal has a thickness in a range of about 0.1mm to about 2 mm.

Wherein the lower seal has a thickness in a range of about 0.3mm to about 1.2 mm.

Wherein the lower seal has a thickness of about 0.65 mm.

Wherein the diameter of the chamber is in the range of 0.06mm to 13 mm.

Wherein the diameter of the chamber is in the range of 0.10mm to 6.5 mm.

Wherein the body comprises a first portion and a second portion, the second portion comprising a recess sized and shaped to receive at least a portion of the first portion.

Wherein the first portion is cylindrical and wherein the recess is sized and shaped to receive at least a portion of the cylindrical first portion.

Wherein the first portion and the recess are in mating engagement by a tongue and groove.

Wherein the chamber is formed between the first portion and the second portion.

Wherein the chamber is cylindrical.

Wherein the chamber is mushroom shaped.

Wherein, the chamber is a hollow chamber.

Wherein the first portion is formed from a first elastomeric material, wherein the second portion is formed from a second elastomeric material, and wherein the first elastomeric material and the second elastomeric material have different mechanical properties.

Wherein the first elastomeric material and the second elastomeric material have different hardness values.

Wherein the septum includes an upper cavity formed in the top surface.

Wherein the septum includes a lower cavity formed in the bottom surface.

Wherein, the upper chamber is conical.

Wherein the upper chamber is flat-bottomed.

Wherein the lower cavity is conical.

Wherein the lower cavity is flat-bottomed.

Wherein the diaphragm includes an upper chamber formed in the top surface and a lower chamber formed in the bottom surface, the central axis extending continuously through the upper chamber, the chamber, and the lower chamber.

Wherein the septum is pre-pierced along the central axis.

Wherein the top surface includes an upper cavity; wherein the central axis extends through the upper chamber; and wherein the step of inserting the needle comprises inserting the needle into the upper chamber, the upper seal, the inner chamber, and the bottom seal in that order along the central axis.

Wherein the bottom surface includes a lower cavity; wherein the central axis extends through the lower chamber; and wherein the step of inserting the needle comprises inserting the needle into the upper seal, the interior chamber, the bottom seal, and the lower chamber in that order along the central axis.

Wherein the top surface includes an upper cavity; wherein the bottom surface includes a lower cavity; wherein the central axis extends through the upper and lower chambers; and wherein the step of inserting the needle comprises inserting the needle into the upper seal, the interior chamber, the bottom seal, and the lower chamber in that order along the central axis.

Wherein the method further comprises retracting the needle after insertion.

Wherein the step of retracting the needle comprises retracting the needle sequentially along the central axis through the bottom seal, the interior chamber, and the upper seal.

Wherein the force required by the insertion needle and the retraction needle does not exceed 4N.

Wherein the force required to insert the needle does not exceed 4N.

The foregoing detailed description has been given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modifications may be made by those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention. Although specific spatial dimensions are illustrated herein, these specific numbers are given by way of example only. If used herein, the reference system generally refers to various directions (e.g., top, bottom, upper, lower, forward, rearward, leftward, rightward, etc.) that are only used to aid the reader in understanding the various embodiments of the present disclosure, and should not be construed as limiting. Other reference systems may be used to describe various embodiments.