Adapter housing and connecting device for chromatography

Abstract

An adapter housing is described that can be used for high performance liquid chromatography, which can be releasably connected to a socket unit. The adapter housing includes a bore which passes through the adapter housing and a pre-column which can be arranged in the bore to protect the separation column from contaminants and/or to concentrate the fluid to be analyzed. A sealing element seals the adapter housing in relation to the socket unit at the end-face wall of a pilot bore.

Claims

1. An adapter housing for receiving a component and configured to be releasably connected to a socket unit, wherein the socket unit comprises: a receiving opening; a pilot bore axially connected to the receiving opening, the pilot bore having a radial wall and an end-face wall, and a socket capillary tube axially connected to the end-face wall, the socket capillary tube configured to direct a fluid to be analyzed, the adapter housing configured to be introduced into the receiving opening, the adapter housing comprises: a connecting portion configured to be releasably fastened to a connector housing to supply the fluid directed through the connector housing; a pre-column arranged in a bore of the adapter housing, where the bore passes through the adapter housing, the pre-column including a packing material, a sealing element is connected to the adapter housing and seals the adapter housing in relation to the socket unit on the radial wall and on the end-face wall when the adapter housing is introduced into the receiving opening of the socket unit, the sealing element surrounds a lateral surface of the pre-column and along an entire length of the pre-column so that the fluid does not come into contact with a material of the adapter housing whilst the fluid flows through the pre-column, in that the sealing element comprises a first sealing portion, a second sealing portion and a third sealing portion, the first sealing portion configured to seal the adapter housing in relation to the socket unit, the second sealing portion surrounding the lateral surface of the pre-column, and the third sealing portion having a radially widened region in relation to the second sealing portion, the third sealing portion is pressed directly or indirectly by a closure against a stop region of the adapter housing for the rearward sealing of the pre-column or for fixing the sealing element.

2. The connecting device of claim 1, in that the third sealing portion is pressed directly or indirectly by a closure against a stop region of the adapter housing for fixing the sealing element.

3. The connecting device of claim 1, in that the pre-column comprises a filter for filtering the fluid to be analyzed and for restraining the pre-column packing material.

4. The connecting device of claim 3, in that the sealing element comprises a through-bore extending coaxially with respect to the socket capillary tube, the through-bore having a smaller diameter than an inner diameter of the second sealing portion to create an end face.

5. The connecting device of claim 4, in that the filter abuts against an end face of the sealing element in a mounted state.

6. The connecting device of claim 1, wherein the closure comprises a central throughchannel for directing the fluid to be analyzed to the pre-column.

7. The connecting device of claim 3, in that the pre-column further comprises a further filter for filtering the fluid to be analyzed and for restraining the pre-column packing, in that the further filter abuts against the closure in the mounted state.

8. The connecting device of claim 7, in that the further filter is incorporated in the closure.

9. The connecting device of claim 1, in that the sealing element is bio-inert along an entire length of the pre-column.

10. The connecting device of claim 1, in that the sealing element is polyetheretherketone.

11. The connecting device of claim 1, in that the sealing element touches the end-face wall of the pilot bore by way of the first sealing portion.

12. The connecting device of claim 1, further comprising a sleeve arranged between an outside of the sealing element and an inner wall of the pilot bore.

13. The connecting device of claim 1, in that the sealing element is deformed elastically or plastically when the adapter housing is mounted in the socket unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is described in detail below by way of preferred exemplary embodiments with reference to the accompanying drawings, in which, in each case by way of a sectional representation.

(2) FIG. 1 shows a connecting device according to the invention with an adapter housing according to a first embodiment which is screwed into a first socket unit.

(3) FIG. 2 shows the connecting device according to the invention shown in FIG. 1, wherein a capillary tube is connected to the adapter housing.

(4) FIG. 3 shows the connecting device according to FIG. 1, wherein the adapter housing is screwed into a second socket unit with a pilot bore length which is longer than that of the first socket unit.

(5) FIG. 4 shows a connecting device with a second embodiment of the adapter housing according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(6) FIG. 1 shows a connecting device 10 according to the invention which includes a first embodiment of an adapter housing 12.sub.1 according to the invention as well as a first socket unit 13.sub.1. The adapter housing 12.sub.1 comprises a bore 14 which penetrates the adapter housing 12.sub.1 completely. The adapter housing 12.sub.1 comprises a first portion 16 with a first outside diameter at which the adapter housing 12.sub.1 is able to be grasped and moved, in particular rotated, by a user. In addition, the adapter housing 12.sub.1 comprises a second portion 18 with a second outside diameter on which is arranged an external thread 20 by way of which the adapter housing 12.sub.1 is able to be screwed into an internal thread 22, which is arranged in a receiving opening 24 of the socket unit 13.sub.1. Over and above this, the adapter housing 12.sub.1 comprises a third portion 26 with a third outside diameter which corresponds approximately to the diameter of a pilot bore 28 which is arranged in the socket unit 13.sub.1. The pilot bore 28 has a length L.sub.1. The first outside diameter is the largest, whilst the third outside diameter is the smallest of the outside diameters of the adapter housing 12.sub.1. The adapter housing 12.sub.1 can be produced, for example, from metal or ceramic.

(7) In the first portion 16, the bore 14 of the adapter housing 12.sub.1 comprises a first opening 30 with a first inside diameter which corresponds approximately to the second outside diameter of the second portion 18.

(8) Arranged in the first portion 16 is a connecting portion 32, which includes an internal thread 34, into which can be screwed a connector housing 36 (cg. FIG. 2), in which is arranged a capillary tube 38 in which the fluid to be analyzed is guided. In the region of the second portion 18, the bore 14 comprises a second inside diameter which is smaller than the first inside diameter, the bore 14 tapering conically from the first to the second inside diameter. In the region of the second inside diameter, the bore 14 comprises a particularly precisely produced fitting portion 40 which is produced with tighter production tolerance. The bore 14 then tapers in a step-shaped manner to a third inside diameter in order then to reduce in a conical manner to a fourth inside diameter. At its front end which is remote from the first portion 16, the bore 14 passes from the fourth inside diameter in a funnel-shaped manner over into the third outside diameter and forms a second opening 42.

(9) An elongated sealing element 44 is inserted by means of the second opening 42 into the bore 14 of the adapter housing 12.sub.1 which comprises a first sealing portion 48 and a second sealing portion 46. The second sealing portion 46 has a substantially hollow-cylindrical form and surrounds a cavity which can be filled out by a pre-column. The second sealing portion 46 comprises an outside diameter which corresponds substantially to the fourth inside diameter of the bore 14 of the adapter housing 12.sub.1. The sealing element 44 can be reshaped and expanded at a third sealing portion 49 at the free rear end of the second sealing portion 46 using a corresponding tool such that it is fixed, for example as a result of clamping by means of a closure (see below), at a stop region of the adapter housing, in particular at the conical transition of the bore 14 from the third to the fourth inside diameter. As a result, the fluid can also be isolated in a contact-tight (bio-inert) manner in relation to the adapter housing in the region of the rear end of the pre-column. In addition, the sealing element can easily be fixed on the adapter housing in this manner.

(10) At the front end, the second sealing portion 46 expands conically onto the first sealing portion 48, where it corresponds with the form of the opening 42. The outside diameter of the first sealing portion 48, in this case, can be chosen to be somewhat larger than the fourth inside diameter of the adapter housing 12.sub.1, and can even be slightly larger than the third outside diameter of the adapter housing 12.sub.1 such that the first sealing portion 48 projects radially somewhat beyond the third portion 26 of the adapter housing 12.sub.1. In addition, the first sealing portion 48 also projects axially somewhat beyond the front end of the adapter housing 12.sub.1.

(11) In the first sealing portion 48, the sealing element 44 comprises a through-bore 50 with a diameter which is somewhat smaller than the diameter of the cavity such that an end face 52 is formed. A pre-column 56 is inserted into the cavity. It includes a filter 58 which touches the end face 52. Arranged adjoining the rear side of the filter is a pre-column packing 60 which abuts against a further filter 62 by way of its rear end. Said filter 62, and with it the entire pre-column, is fixed by a closure 64 which comprises a through-channel 65 for the fluid to be analyzed to pass through. The sealing element 44 can be produced from a plastics material such as polyetheretherketone (PEEK). It is possible, in particular, to use biocompatible materials.

(12) The third portion 26 of the adapter housing 12.sub.1 can be introduced into the pilot bore 28 of the socket unit 13.sub.1 which, in the example shown, passes over into the expanded receiving opening 24 via a conical transition region 78. The pilot bore 28 comprises a radial wall 66 and an end-face wall 68. A socket capillary tube 70, by means of which the fluid to be analyzed is guided to a separation column (not shown), connects to the end-face wall 68 axially and concentrically with respect to the axis of the pre-column 56. (Not shown is a realization variant of the socket unit where a comparable further receiving opening is provided in the housing of the socket unit on the end of the socket capillary tube 70 which is remote from the receiving opening 24. The separation column or another HPLC component could be connected here by means of a connector unit instead of realizing the socket unit integrally with or at any rate as part of the separation column.)

(13) In order to be able to use the adapter housing 12.sub.1 in a functional manner, the sealing element 44 is initially inserted by means of the second opening 42 into the bore 14 of the adapter housing 12.sub.1. If the sealing element 44 is produced from a suitable plastics material, it can also be injected directly into the bore 14. Using a corresponding tool, the sealing element 44 is deformed at its free rear end such that it abuts against the conical transition from the third into the fourth inside diameter of the bore 14, as a result of which the position of the sealing element is fixed. The filter 58, the pre-column packing 60 and the further filter 62 are then introduced into the sealing element 44 by means of the first opening and closed by way of the closure 64. The position of the closure 64 is fixed by the inside diameter of the bore 14 which reduces in a step-like manner such that the pre-column packing 60 is not able to be compressed too strongly.

(14) In addition, the closure 64 can be clamped, for example by means of an intermediate part which acts in a rearward manner and thus, depending on production dimensions and tolerances, can determine, in a targeted manner, the packing density of the pre-column packing and remove air out of the pre-column. As the position of the closure 64 is fixed, the sealing element 44 and the pre-column 56 are also consequently correctly positioned such that faulty installation is as good as impossible.

(15) The adapter housing 12.sub.1 is then connected to the socket unit 13.sub.1, to which end the adapter housing 12.sub.1 is introduced into the receiving opening 24 of the socket unit 13.sub.1. During said introduction, the third portion 26 of the adapter housing 12.sub.1 is centered by way of the conical transition region 78 such that the third portion 26 is guided into the pilot bore 28. The end-face wall 68 comprises a smooth, planar surface such that an optimum connection without any dead volumes and optimum sealing are provided.

(16) The adapter housing 12.sub.1 is screwed into the internal thread 22 of the receiving opening 24 until the sealing element 44 touches the end-face wall 68 of the pilot bore 28 by way of the first sealing portion 48. Particularly good sealing can be produced as a result of the first sealing portion 48, which projects forward from the adapter housing, when the adapter housing is moved forward, being acted upon with an axial compressive force which results in elastic or plastic deforming of said sealing portion also in the radial direction. The seal then fits snugly to the end face 68 or the wall 66 completely filling out any dead spaces possibly existing and providing a complete seal.

(17) Once the adapter housing 12.sub.1 is screwed into the socket unit 13.sub.1, a capillary tube 38, for example, can now be connected to the adapter housing 12.sub.1, which is shown in FIG. 2. In the example shown, the connector housing 36 comprises an external thread 72 which can be screwed into the internal thread 34 of the connecting portion 32 of the bore 14 of the adapter housing 12.sub.1. The capillary tube 38 projects axially beyond the connector housing 36. An intermediate piece 74, which comprises an outside diameter which corresponds substantially to the second inside diameter of the bore 14, is pushed onto the projecting portion of the capillary tube 38. The capillary tube 38 is sealed in relation to the adapter housing 12.sub.1 by means of a further sealing element 76 and, in this case, abuts against an end face 80 of the closure 64.

(18) The capillary tube 38 is consequently connected to the closure 64 butt to butt. The further sealing element 76 seals the capillary tube 38 both at the end face 52 of the closure 64 and in relation to the bore 14 such that, here too, no dead spaces worth mentioning can be created. Sealing is effected in an analogous manner to that in the pilot bore 28 by the sealing element 76 being caused to deform elastically or plastically as a result of pressure being applied by means of the intermediate piece 74 in order to fill and to seal sealing gaps in a complete manner. Using conveying devices which are not shown, the fluid to be analyzed is conveyed from behind through the capillary tube 38, the closure 64, the pre-column 56, the through-bore 50 and the socket capillary 70.

(19) It is also possible, however, to connect differently constructed connector housings to the adapter housing 12.sub.1. In addition, the closure 64 could be omitted and its function taken over possibly by the intermediate piece 74. The closure 64 could also be connected fixedly to the adapter housing 12 as a rear stop or could even be realized in one piece with said adapter housing. The third sealing portion 49 could then be expanded during assembly, for example by means of a conical stop face of the closure 64, and clamped firmly in place.

(20) In FIG. 3, the adapter housing 12.sub.1 shown in FIGS. 1 and 2 is screwed into a second socket unit 13.sub.2 which comprises a pilot bore 28 with a greater length L.sub.2 compared to the first socket unit 13.sub.1 which is shown in FIGS. 1 and 2. It can be seen that the adapter housing 12.sub.1 can be introduced without modification into pilot bores with different lengths. The single pre-requisite is that the second portion 18 of the adapter housing 12.sub.1 is long enough, which is able to be met, however, without a great deal of expenditure. Said flexibility is essentially achieved as a result of the sealing element 44 sealing the end-face wall 68 of the pilot bore 28 in an axial manner such that the necessary surface pressure is determined by how far the adapter housing 12.sub.1 is screwed into the socket unit 13.

(21) FIG. 4 shows a second exemplary embodiment of the adapter housing 12.sub.2 according to the invention. It differs substantially from the first exemplary embodiment in that the further filter 62 is incorporated in the closure 64 and that the bore 14 only comprises three diameters which all merge into one another in a step-shaped manner. As a result, the sealing element 44 is not pressed against a conical transition, but against a step-shaped transition and is fixed in its position.

LIST OF REFERENCES

(22) 10 Connecting device 12, 12.sub.1, 12.sub.2 Adapter housing 13, 13.sub.1, 13.sub.2 Socket unit 14 Bore 16 First portion 18 Second portion 20 External thread 22 Internal thread 24 Receiving opening 26 Third portion 28 Pilot bore 30 First opening 32 Connecting portion 34 Internal thread 36 Connector housing 38 Capillary tube 40 Fitting portion 42 Second opening 44 Sealing element 46 Second sealing portion 48 First sealing portion 49 Third sealing portion 50 Through-bore 52 End face 54 Sleeve 56 Pre-column 58 Filter 60 Pre-column packing 62 Further filter 64 Closure 65 Through-channel 66 Radial wall 68 End-face wall 70 Socket capillary tube 72 External thread 74 Intermediate piece 76 Further sealing element 78 Conical transition portion 80 End face A Longitudinal axis P Arrow