US 3374660 A
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March 26, 1968 c. B. MCKINNEY ET AL 3,374,660
INLET FOR CHROMATOGRAPHS AND THE LIKE Filed June 28, 1966 INVENTORS.
United States Patent 3,374,660 INLET FOR CHROMATOGRAPHS AND THE LIKE Carlton B. McKinney, Los Angeles, and William M. Sheppard, Whittier, Calif., assignors to Hamilton Company, Whittier, Califi, a corporation of California Filed June 28, 1966, Ser. No. 561,085 19 Claims. (Cl. 73-23.1)
This invention relates generally to chromatography and the like and relates more particularly to inlets for chromatographs.
While the invention ha particular utility in connection with inlet for gas chromatographs, andis shown and described in such connection, it is to be understood that its utility is not confined thereto.
As is well known in the art there are certain problems involved in the provision of inlets for chromatographs, one of said problems is band spreading which occurs in such gas chromatographs of which I am aware and it is an object of the invention to provide an inlet wherein such band spreading is prevented or substantially eliminated and separation by the column is enhanced.
Still another object of the invention is to provide an inlet for chromatographs having means for applying a suitable compression force or pressure on the septum at all times. A further object of the invention is to provide an inlet for chromatographs wherein the septum seals instantly when the needle is withdrawn thus preventing back-flow of the sample and substantially improving quantitative injection. A further object is to provide an inlet of this character wherein needle cuts and extrusion of pieces of the septum into the inlet are minimized or eliminated. A still further object is to provide an instrument of this character wherein the problem of absorption or reaction of sensitive samples on metal surfaces or the like is eliminated. Another object of the invention is to provide an instrument of this character.
A still further object of the invention is to provide an inlet havingmeans for guiding the needle into the instrument, through the septum and into the carrier fluid passage without hang-up. Another object of the invent on is to provide an inlet with which shallow injection may be made to prevent vaporization of uncontrolled quantities of sample from the needle of the sampling syringe. Still another object is to provide such an instrument having means for preheating the carrier gas and keeping it at a uniform temperature. A further object of the invention is to provide a chromatograph inlet wherein the vaporizing tube may be packed with absorbent or filtering material orsome selective reactive material to retain or modify some part or component of a sample. The vaporizer tube may be packed for on-column injection or pre-column chemistry.
A still further object of the invention is to provide an inlet for chromatographs and the like which may be quickly and accurately assembled, wherein the septum may be easily and quickly replaced, and wherein there is easy access to the inner parts for replacement and/or cleaning. This is all possible by reason of the spring loaded retainer.
Broadly the invention concept comprises an inlet for chromatographs and the like having means defining a fiow passage for a carrier fluid, with a relatively small opening for reception of a small diameter part of an instrument for introduction into said passage of a sample to be analyzed, a penetratable septum covering said opening for sealing same, a septum retainer engageable with said septum, and resilient means for resiliently urging the septum retainer against the septum so that said septum is under a predetermined and correct pressure.
More particularly the invention provides an inlet for chromatographs and the like having an outer body of material that provides even distribution of heat from a heater so as to eliminate cold spots. The flow passes cleanly to the column through a glass vaporizer tube without band spreading voids, the flow path being such as to pre-heat the incoming carrier gas. There is provided high velocity for the pre-heated gas stream that continuously washes the septum area, the septum being exposed to material in the inlet is extremely small, being practically zero. There is also a unique spring-loaded retainer which permits quick replacement of septums and allows easy access to the inner parts for replacement or cleaning and the constant pressure of the spring causes the septum to instantly seal when the needle is withdrawn.
The characteristics and advantages of the invention are further sufiiciently referred to in connection with the following detailed description of the accompanying drawings which represent one embodiment. After considering this example, skilled persons will understand that many variations may be made Without departing from the principles disclosed and we contemplate the employment of any structures, arrangements or modes of operation that are properly within the scope of the appended claims.
Referring to the drawings, which are for illustrative purposes only:
FIG. 1 is a side elevational view of an inlet embodying the present invention attached to a chromatograph;
FIG. 2 is an enlarged longitudinal sectional view through the inlet;
FIG. 3 is an enlarged perspective view of the outer end of the vaporizer tube;
FIG. 4 is an enlarged perspective view of the outer end of the liner;
FIG. 5 is a fragmentary, enlarged view of the knob for the septum retainer assembly; and
FIG. 6 is an enlarged sectional view through the vapon'zer tube with packing therein.
Referring more particularly to FIGS. 1 and 2 there is shown and inlet embodying the present invention, said inlet being indicated generally at 10, removably attached to a chromotograph, indicated at 12.
The inlet 10 comprises an elongated main body 14 of a metal that is a good heat conductor, aluminum being a metal that meets the requirements satisfactorily.
Body 14- has a bore or passageway 16 extending longitudinally therethrough with an internally threaded forward end portion 18, for reception of a threaded part 20 of a column fitting, indicated generally at 22. This fitting is well known and has a hexagonal head 24 for engagement by a suitable wrench or other tool for turning same. There is also a nipple 26 extending forwardly from the head 24 and provided with an enlarged externally threaded end portion 228 for screwing into a tapped opening in the chromatograph column. A bore 30 extends from the inner or rear end of the fitting and terminates in a shoulder 32 intermediate the ends of said fitting, from which a reduced diameter bore 34 extends forwardly and terminates in an enlarged recess from which the passage flares, as at 36.
The main body 14 is square in cross section although it may be of other configuration, and at the rear end said body has a disc-like knob or head 40 spaced rearwardly of the rear end of the main body 14 and connected therewith by means of a reduced diameter part 42, the bore 16 extending through the head or knob 40 and neck 42.
There is a vaporizer tube 46 defined by a cylindrical wall and having a passage 48 extending longitudinally therethrough, said tube being of glass which is inactive although any other suitable material may be used. A forward end portion of the vaporizer tube is rather snugly received in the bore 30 of the fitting with the forward end of the tube 46 abutting against the shoulder 32 of said fitting, the rear end of said vaporizer tube then being spaced inwardly or forwardly of the rear end of the bore or passage 16, it being noted that the diameter of the bore 34 of the fitting is substantially the same as the passage 48 through the vaporizer tube so that there will be a smooth flow of fluid through the passage 48 and bore 34.
Vaporizer tube 46 has a substantially smaller external diameter than the diameter of the passage 16 of the body so that there is an annular space between the vaporizer tube and the wall of the body passage 16.
A tubular liner 50 is disposed on the vaponzer tube 46, said liner also being of glass although it may be of any other suitable material. The outside diameter of the liner is such as to fit rather snugly in the bore 16 of the body and the diameter of the passage 52 extending longitudinally of the liner is greater than the external or outside diameter of the vaporizer tube to thereby provide an annular space 54 which may be termed an annular flow passage between the vaporizer tube and the liner.
The liner is shorter than the vaporizer tube and is open at the forward end but is provided with an outer end wall 56 having a small opening 58 therethrough which IS 111 alignment with the passage 48 of the vaporizer tube. The end wall 56 of the liner abuts against the outer end of the vaporizer tube and in order to provide a fluid connection between the passage 54 and the passage 48 of the vaporizer tube there are a pair of diametrically opposite notches 60 in the rear end of said vaporizer tube so that fluid may flow from the annular passage 54 through said notches and into the passage 48 of the vaporizer tube.
Since the liner 50 is shorter than the vaporizer tube the annular space between the vaporizer tube and ad acent wall of passage 16 comprises .an annular chamber 64 between the forward end ofsaid liner and the inner end of the fitting 22, said chamber communicating with the annular flow passage 54 between the liner and the vaporizer tube.
There is an input fitting 220, similar to the fitting 22, which is screwed into a laterally arranged tapped bore 66, said input fitting being adapted to be connected with a source of carrier fluid under pressure which is supplied to said chamber 64 through passage 22b of said fitting. A seal 68 is provided for the fitting 22a.
A septum 70 is positioned against the outer side of the end wall 56 of the liner to provide a seal for the opening or hole 58. Septum 64 is cylindrical or disc-shaped and fits snugly within the passage 16 of the body so that the periphery of said septum is in or is substantially in contact with the adjacent portion of the wall of said passage 16.
The septum 70 shown here is of the character shown and described in the McKinney application for a Septum, Ser. No. 496,337, filed Oct. 15, 1965. This septum has a relatively soft central layer or ply 71 and an outer, harder layer 73 at each side of the central layer. The material of the central layer of the septum is a soft silicone rubber comprising an unfilled compound 30:5 Shore A. The outer layers are hard red filled compound 60:5 Shore A.
This septum has been found to be very effective and satisfactory but it is to be understood that the septum may be of other character and of other material. However, the septum should have substantial thickness, as pointed out and described in the above mentioned application Ser. No. 496,337.
Means is provided for retaining the septum, liner and vaporizing tube in position within passage 16 of the body, said means comprising a cylindrical member 76 which is termed the septum retainer. This septum retainer is slidable into and out of the outer end portion of the passage 16 of the body but is close fitting within said passage.
There is means for y g the septum retainer and for urging Same r ly f the passage 16 with a predetermined pressure, said means and the septum retainer comprisingwhat is termed herein a septum retainer assembly Wl'11Ch 1S indicated generally at .8-.
The retainer 76 has an axial passage 78 which is termed a needle guide passage the outer end of which flares, as at 80, to facilitate insertion of a needle or the like into said guide passage 78.
The retainer is carried by an arm 84 adjacent the free end thereof there being an annular groove 86 adjacent the outer or rear end of said septum retainer there being a reduced diameter flange 88 at the rear end of the septum retainer. Arm 84 has an opening 90 therethrough in which the rear portion of the retainer 76 is received. The longitudinal extent of the groove 86 is greater than the thickness of the arm 84 and a spring retainer is removably disposed in said groove at the outer side of the arm 84 between said arm and the flange 88, thereby securing the septum retainer 76 to the arm 84.
Arm 84 has a hole therein adjacent the opposite end thereof for reception of a reduced diameter externally threaded rear end portion 90 of an arm supporting shaft 92, there being a shoulder 94 at the inner or forward end of said reduced diameter portion 90 against which said arm is positioned. There is a cylindrical, externally knurled knob 96 disposed on said portion 90 of the shaft 92, said knob being hollow and provided with an inner or forward end wall 98 having an opening 99 therethrough of larger diameter than the diameter of the reduced diameter portion 90 and insulated therefrom by means of a pair of oppositely arranged plastic washers 100 of larger diameter than the opening 99 in the wall 18 of the knob, said washers being of any suitable plastic material such as nylon for example. Washers 100 have axial holes therethrough with an annular, axially extending flange 102 thereabout, the external diameter of the flanges is such as to be received within the opening 99 in the forward end wall 98 of the knob. The combined length of the flanges 102 is less than the thickness of the knob wall 98 and there is a nut 104 on the reduced diameter portion 90 of shaft 92 for securing the washers and knob on said reduced diameter portion 90. Thus the knob is insulated against heat from the shaft 90 and the rest of the inlet assembly.
Means for operably supporting the shaft 92 comprises a pair of spaced rear and front blocks and 112 disposed between top and bottom plates 114 and 116 and secured therebetween by screws 118 disposed in aligned openings adjacent the corners of said plates and adjacent the ends of said blocks, there being nuts 120 on said screws. Shaft 92 is slidably disposed in aligned openings 93 provided therefore in said blocks 110 and 112. The top and bottom plates have spaced openings therein adjacent the side edges thereof, corresponding openings in the top and bottom plates being in axial alignment with each other, the openings indicated at 123 in the lower plate being larger than the openings in the top plate for reception of stem portion 124 of supporting posts, indicated generally at 126. Posts 126 have tapped bores, not shown, extending longitudinally upward end portions for reception of screws, described hereinafter. At the lower ends of said posts are hexagonal, or other suitably shaped, nut portions 128 to accommodate a wrench or other tool for holding the posts 126 against rotation. The stems 124 of the posts 126 do not touch the lower plate because of the size of the openings. The top plate rests on the upper ends of the stems 124'and there are tapped bores extending longitudinally into the stems 124 from the upper ends thereof, said tapped bores registering with the intermediate openings in the top plate and receive screws 130 which secure the retainer supporting structure to the posts 126.
There is a coil spring 134 disposed on the shaft 92 between the rear end block 110 and a washer 136 held in operative position by a pin 138 secured in a cross bore, not shown, provided therefor in the shaft 92, said spring being under compression and adapted to yieldingly resist rearward movement of said shaft 92. Since the spring is external it is cool.
When the septum retainer 76 is disposed in the rear end portion of the bore 16 of the body 14 spring 134 urges the lever 14 forwardly so that the forward free end of the septum retainer is pressed against the adjacent side of the septum 70 with a predetermined pressure. The septum is correspondingly urged against the adjacent rear end wall 56 of the liner 50 and since said end wall 56 rests against the adjacent end of the vaporizer tube 46 the latter is also urged forwardly against the shoulder 32 of the fitting 26. Thus the septum, liner and vaporizer tube are securely held in place within the bore 16 of the body 14.
The pressure of the septum retainer 76 on the septum also compresses the septum and causes it to expand radially so that the peripheral edge of the septum is forced outwardly into sealing engagement with the adjacent portion of the wall of bore 16, the central, softer layer of the septum being pressed radially outward into effective sealing engagement with the adjacent wall portion of the bore 16.
There is means for heating the carrier fluid and sample, said means comprising an electric heater such as cartridge heater 140 disposed in a groove 142 provided therefor in the under side of the body 14 and secured in said groove by a plate 144 having a plurality of holes therein for reception of screws 146, said screws extending upwardly through bores provided therefor in the body 14 and being screwed into tapped bores in the lower ends of the posts 126. Groove 142 is longer than the cartridge heater and electric Wires 148 are received in said groove to supply electric current to said heater.
Preferably the inlet is attached to the chromatograph without the inner parts thereof, the column fitting being attached to the analytical column of chromatograph.
With the septum retainer swung out of the way the vaporizer tube is slid into the bore 16 with the cross cut end toward the septum or rear end of the inlet. The for- Ward end of the vaporizer tube must be disposed within the bore 30, and seats easily and fully into this bore which is a precision bore. Thereafter the liner 59 is inserted into the bore 16 of the body 14 and over the vaporizer tube. The septum is then inserted into the rear or outer end of the bore 16 and the septum retainer pulled back by means of the heat insulated knob 96 and swung over the septum. The arm 84 positions the septum retainer in alignment with the bore 16 and it is moved into said bore by the force of spring 134. The retainer then is partially in the inlet bore resting freely on the septum with the full spring force effective on the septum for compressing said septum and holding it together with the liner and vaporizer tube in operative position. With this arrangement one spring holds the entire assembly in place and because the spring will yield there is accommodation for temperature expansion.
Removal of the inner parts is efiected in reverse order, utilizing a tool which has a small hook at the forward end and all of these parts are removable from the outer free end of the inlet.
It will be readily apparent that there is thus easy access to the inner parts which can be easily and quickly removed for cleaning of residue or the like from the vaporizer tube or vaporizing chamber. Also, the septum can be easily and quickly changed.
The heater 140 is supplied with electric current from a suitable source through the wires 148, a variable transformer or other suitable device being used in the electric circuit to the heater.
A carrier fluid is supplied to the inlet by means of a conduit 150 from a source of such fluid under pressure, said conduit being connected to the input fitting 22a. Helium or other suitable gas may be used as the carrier fluid or gas.
The carrier gas passes from conduit 150 into the longitudinally extending passage through the inlet fitting, into the annular inlet chamber 64, thence into the annular 6 passage 54, through the notches 60, into the vaporizer passage 48, through the bore 34 of the column fitting 22 and into the column of the chromatograph.
Insertion of the needle, indicated at 151, of the sample handling syringe indicated at 153 in FIG. 2, is through the needle guide passage 78 of the septum retainer. It is to be understood that the septum retainer has a slightly loose connection with the arm 84 and therefore the guide passage will be automatically aligned with the opening 58 in the end wall of the liner.
The needle is further inserted through the septum and into the adjacent end of the vaporizer tube, this procedure being effected without hang-up. Insertion of the needle into the vaporizer tube can be very shallow and when the needle has been inserted to the desired depth the sample is discharged therefrom into the passage 48 of said vaporizer tube.
The septum is always under correct compression, just the right amount of pressure being exerted by the spring 134. There is not so much pressure as to cause the needle to carry pieces of rubber into the flow passage but enough pressure to provide an effective seal by the septum. Also, there is instantaneous sealing of the septum when the needle is withdrawn by reason of the pressure on the septum and rapid and repeated insertions of the needle can be made.
It is to be noted that the hole 58 through the end wall 56 of the liner is very little larger than the diameter of the needle so that leakage through said hole is minimized or substantially eliminated. Further, the inside diameter of the passage 48 of the vaporizer tube is small so that the needle nearly fills said passage diametrically speak mg.
The concentric tube arrangement provides a flow geometry that is particularly effective in eliminating or minimizing band spreading and enhancing desired separation.
The carrier gas is pre-heated by the heater 140, the gas stream having a high velocity through the flow path or passages of the inlet and the sample is injected into this flow path in the direction of fluid flow.
Because of the relatively large mass of aluminum body and the high heat conductivity thereof there is an even, uniform and quick distribution of heat from the cartridge heater and cold spots are eliminated.
Since the vaporizer tube and liner, which may also be considered a closed end tube, define the flow passages through the inlet and are of inert glass, sensitive compounds or samples are protected from metal surface decomposition. Thus the sample can only contact an inert material.
The carrier gas flowing at a high velocity washes the septum area, restricts flash-back and passes cleanly through the vaporizer tube to the column without band spreading voids and carries along the sample injected into the vaporizer tube passage 48.
As the carrier gas is pre-heated the sample injected into the vaporizer tube is quickly vaporized. Due to the small septum area exposed to the fluid in the flow path through the opening 58 in the end wall of the liner and the needle disposed in said opening practically no vaporized sample material contacts the septum. Also, due to the small cross sectional area of the passage 48 of the vaporizer tube and the presence of the needle therein at the outer end back-up is minimized. Further, the sample flows smoothly and without turbulence and there is no dead volume in the sample flow path.
For certain situations it is desirable to retain some part of a sample to prevent column contamination and this can be effected by packing the passage 48 in the vaporizer tube with absorbent, filtering or some selective reactive material. That is, the vaporizer tube may be packed with column material for on-column injection or reactants for pre-column chemistry.
For example, for analyzing alcohol in blood, the vaporizer tube could be packed with glass wool to retain the blood solids while water and alcohol is vaporized and flushed into the chromatograph.
In FIG. 6 there is shown a vaporizing tube 46 with packing material 160 in the passage 48 thereof.
As pointed out above, the inner parts may be easily and quickly removed from the body 14 for cleaning or replacement. Particularly the vaporizer tube may be removed and cleaned While another tube is being used in the instrument.
The invention and its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing its material advantages, the arrangement hereinbefore described being merely by Way of example, and we do not wish to be restricted to the specific form or uses mentioned except as defined in the accompanying claims, wherein various portions have been separated for clarity of reading and not for emphasis.
1. In an inlet for analytical apparatus and the like:
(A) support means;
(B) a tubular inner operably supported by said support means, said liner having a passage extending longitudinally therein, there being a wall at one end with a relatively small instrument opening therethrough for operable reception of a needle of a sample handling instrument;
(C) a vaporizer tube operably supported by said support means, at least a portion of said vaporizer tube being disposed in the liner passage, said vaporizer tube having a longitudinallyextending passage therethrough, the outside diameter of said vaporizer tube being of smaller diameter than the inside diameter of said liner to thereby provide an annular fluid passage between the liner and the vaporizer tube, the opening in the end wall of the liner being aligned with the passage through the vaporizer tube, there being fluid communication between the space between the liner and vaporizer tube at the end of the liner having the end wall; a
(D) and a septum operably disposed against the outer side of the end wall of the liner.
2. The invention defined by claim 1 wherein the support means comprises a body having a bore therein in which the liner is operably disposed with the vaporizer tube operably supported within the tube, the septum being disposed in the body bore.
3. The invention defined by claim 1 and including retaining means for pressing the septum against the end wall of the liner.
4. The invention defined by claim 3 wherein the liner, vaporizer tube, and the septum are removably held in operable position by the supporting means, the retaining means for pressing the septum against the end wall of the liner, vapoizing tube and septum being movable to a position releasing said liner, vaporizing tube and septum so that they may be removed from the supporting means.
5. The invention defined by claim 1 wherein the liner and vaporizer tube are of inactive material.
6. The invention defined by claim 1 wherein the liner, vaporizer tube and septum are of inactive material.
7. The invention defined by claim 3 wherein the retaining means resiliently presses the septum against the end wall of the liner.
8. The invention defined by claim 1 and including means for heating the support means and hence the liner and vaporizer tube.
9. An inlet for analytical apparatus and the like:
(A) a body having a bore therein;
(B) a tubular liner of inactive material operably disposed in said bore, said liner having a longitudinally extending passage therein and having an outer end wall with a small opening therethrough for reception of a small diameter part of a sample introducing instrument;
(C) a vaporizer tube having a longitudinally passage therethrough, the vaporizer tube being of smaller outside diameter than the inside diameter of the liner to provide space for the flow of fluid therebetween, the outer end of said vaporizer tube having notch means therein and abutting against the end wall of the liner, said notch means providing fluid communication between the space between the vaporizer tube and the liner and the interior of the liner, said vaporizer tube being open at both ends and the passage in said tube being aligned with the opening in the outer end wall of the liner,
(D) and a septum disposed in said bore and against the end wall of the liner.
10. The invention defined by claim 9 including a septum retainer urging the septum against the end wall of the liner.
11. The invention defined by claim 10 wherein the septum retainer is resiliently urged against said septum, said septum retainer having an instrument guide passage therethrough in alignment with the opening in the end wall of the liner.
12. The invention defined by claim 11 wherein the septum retainer is positioned in the bore when in the septum retaining position, but movable to a release position out of said bore, said liner, vaporizer tube and septum being removable from the bore in said body when said septum retainer is in said release position.
13. The invention defined by claim 9, wherein there is a fitting in the forward end of the bore in said body, said fitting having an axial recess therein for reception of the forward end of the vaporizer tube, there being a shoulder at the forward end of said recess against which the forward end of said vaporizer tube abuts, said fitting having an outlet passage from said recess, the liner being shorter than the vaporizer tube so that there is an annular chamber between the exterior of the vaporizer tube and the adjacent wall portion of the bore, said chamber being closed at the forward end by said fixture but communicating with the space between the inner surface of the liner wall and the exterior surface of the vaporizer tube; there being means for connecting said chamber with a source of fluid under pressure.
14. The invention defined by claim 11, wherein the outer end of the liner is spaced inwardly of the outer end of the bore in the body, and the septum is disposed in said bore at the outer end of the liner and against the end wall of said liner, and the septum retainer includes a cylindrical part slidable into the outer end of said bore and into engagement with the outer side of the septum, the resilient pressure of the septum retainer on said septum serving to retain the septum, the liner and the vaporizer tube in operating position in said bore.
15. The invention defined by claim 11, wherein the instrument guide passage and the opening in the end wall of the liner are of such size that the needle of a sample introducing instrument is operably and slidably receivable therein, the passage through the vaporizer tube being slightly larger than. the external diameter of said needle to provide for the flow of fluid therebetween.
16. The invention defined by claim 9, including heater means for heating said body.
17. The invention defined by claim 11, wherein the bore in the body is cylindrical and the septum is circular and fits snugly in said bore, the resilient pressure of the septum retainer on the septum urging the periphery of said septum into sealing engagement with the adjacent wall portion of the bore as well as into sealing engagement with the end wall of the liner.
18. In an inlet for chromatographs and the like:
(A) an elongated body having a longitudinally extending passage therethrough;
(B) a column fitting secured in one end of said passage,
said fitting having an axial bore extending forwardly from the inner end and from the forward end of which a reduced diameter fluid discharge bore extends;
(C) a vaporizer tube of inactive material, said tube being of smaller outside diameter than the inside diameter of the passage through the body, a forward end portion of said vaporizer tube being snugly received in the axial bore of said fitting, the outer end of said vaporizer tube being spaced rearwardly of the outer end of the passage through the body and having notch means therein;
(D) a liner of inactive material, said liner having a passage extending longitudinally therein, there being a wall at the outer end of said passage with a relatively small instrument axial opening therethrough, for reception of the needle of a sample handling instrument, the outside diameter of the liner being such as to be snugly received in the passage of the body, the inside diameter of said liner being greater than the outside diameter of the vaporizer tube and fitting over an outer end portion of said vaporizer tube to provide an annular chamber about the vaporizer tube having a fluid connect with the interior of said vaporizer tube, there being an inlet into said annular chamber, the outer end of said liner being spaced inwardly of the outer end of the passage through the body With the Wall at the outer end of said liner resting on the outer end of the vaporizer tube, the
opening in the end Wall of the liner registering with the passage through the vaporizer tube;
(E) a septum in the outer end portion of the body passage, said septum abutting the outer side of the liner end wall;
(F) a septum retainer slidable and removably received Within the outer end portion of the body passage, said retainer having a small axial guide bore for reception of a needle of a sample delivering instrument, said guide bore being aligned with the opening in the end wall of the liner;
(G) and resilient means for urging said retainer against the septum with a predetermined pressure.
19. The invention defined by claim 9 including means 15 for releasably retaining the liner and the vaporizing tube in the bore of the body.
References Cited FOREIGN PATENTS 739,179 7/1966 Canada.
OTHER REFERENCES Beckman Instruments Inc.: bulletin 7032, pp. 10, 11.
25 RICHARD c. QUEISSER, Primary Examiner.
VICTOR I. TOTH, Assistant Examiner.
Citas de patentes