US3777572A

US3777572A - Method and apparatus for automatic sample loading for chromatography columns

Info

Publication number: US3777572A
Application number: US00747006A
Authority: US
Inventors: J Hrdina
Original assignee: Czech Academy of Sciences CAS
Current assignee: Czech Academy of Sciences CAS
Priority date: 1964-06-01
Filing date: 1968-07-11
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11
Also published as: FR1435538A; GB1111664A; SE332903B; JPS5233518B1; DE1598223A1; DE1598223B2; CH447657A

Abstract

A device for metering successive samples in to the input of a chromatography column. A device including plurality of sample receptacles, each of which can be loaded in advance, is connected by means of hydraulic switching means to a pump and the column. The hydraulic switching means can either connect the pump directly to the column or direct eluent from the pump through receptacles and then to the column.

Description

United States Patent [191 Hrdina [111 3,777,572 Dec. .11, 1973 METHOD AND APPARATUS FOR AUTOMATIC SAMPLE LOADING FOR CHROMATOGRAPHY COLUMNS [75] Inventor:

[73] Assignee: Ceskoslovenskaakademie ved,

Prague, Czechoslovakia [22] Filed: July 11, 1968 [21] Appl. No.: 747,006

Related U.S. Application Data [63] Continuation of Ser. No. 458,081, May 24, 1965,

abandoned.

Jiri Hrdina, Prague, Czechoslovakia [30] Foreign Application Priority Data June 1,, 1964 Czechoslovakia 3161/64 52 U.S. cl......-...73/422 'GC, 73/61.1 c, 73/423 A 51 IIIL'CI. c0111 ms 58 FieldotSearch 73/422GC,61.1,

[56] References Cited UNlTED STATES PATENTS l/1970 Thomas et al. 73/61.1

3,220,246 11/1965 Barnum 73/61.l 3,253,468 5/1966 Schultz 2,757,541 8/1956 Watson 2,830,738 4/1958 ,Sorg et al....

3,160,015 12/1964 Charlt0n.....

2,973,117 2/1961 Conklinm. 73/422 UX FOREIGN PATENTS OR APPLICATIONS 947,480 1/1964 Great Britain 73/422 Primary Examiner--S. Clement Swisher Attorney-Paul l-l. Smolka [57] ABSTRACT A device for metering successive samples in to the input of a chromatography column. A device including plurality of sample receptacles, each of which can be loaded in advance, is connected by means of hydraulic switching means to a pump and the column.

The hydraulic switching means can either connect the pump directly to the column or direct eluent from the pump through receptacles and then-to the column.

15 Claims, 6 Drawing Figures PATENIED DEC I 1 i973 SHEET 2 [IF 2 FIG. 4

V 1 m y Q Sumo/Mom FIG.

FIG.

JIRI HRDINA G K I 1 METHOD AND APPARATUS FOR AUTOMATIC SAMPLE LOADING FOR CHROMATOGRAPHY COLUMNS This application is a continuation of my application Ser. No. 458,081 filed May 24, 1965, now abandoned.

be transferred at the beginning of any analysis automatically into the column from sample receptacles, into which they have been brought manually within time periods convenient for the attending operator. In up-todate efficient systems, it may be necessary to place into the receptacles a plurality of samples in order to make full use of the apparatus capacity. In modern apparatus this capacity may reach up to five to about 20 analyses in 24hours.

Ineffective modern apparatus all sources of undesirable deterioration of the separation of the mixture performed on the column should be suppressed. For this reason the sample receptacle should be placed as near as possible in front of the column, i.e., in the pressure branch of the pump forcing the eluent into the column. In order to meet the condition of a minimum undesired contribution of the metering device to the decrease of the completeness of the separation of the mixture or respectively of minimizing the blurring of the concentration zones, the connecting tubing between the sample receptacle and the column should be capillary, as short as possible and its interior surface should retain the minimum possible amount of the sample. The same conditions apply to the sample receptacle itself. Moreover, the metering device should, within the shortest possible time, assure the transfer of the whole sample at the beginning of the analysis from the sample receptacle to the column. Finally, care must be taken, of course, to avoid any leakage in the apparatus under the pressure used enabling any escape of portions of the sample into parts outside the metering system.

The condition of complete tightness of the apparatus cannot be easily met in practice, particularly in view of the fact that for the easy filling of the sample receptacle it is necessary to disengage one or both ends of the sample receptacle from the pressure input.

The process and apparatus according to the present invention is designed to avoid the above mentioned difficulties. The substance of the invention consists that the individual samples are preliminarily sucked into sample receptacles and remain at first outside the pressure input of the pump transporting the liquids through the apparatus and are placed into the pressure input not earlier than when the sample should be transferred into the chromatography column at the beginning of the analysis. The transfer of the sample from the sample receptacle into the chromatography column is carried out by the action of the pump delivering the eluent into the column following a path which does not contain any of the said sample receptacles except in the metering period during which a single one of the said sample receptacles is connected into the flow circuit which is pressurized by the pump whilst the other sample receptacles remain unconnected with this pressurized circuit.

In the apparatus for carrying out the process according to the present invention the sample receptacles are individually placed into the pressurized pump circuit via at least one multi-way value and at least one, by draulic distributor, such that in one: of the positions of at least one of the hydraulic distributors the pump is directly connected with the column and the individual sample receptacles are outside the pressure cycle of the pump.

The accompanying drawings illustrate diagrammatically the apparatus according to the invention by way of example.

FIG. 1 shows a front view partly in section of the metering device,

FIG. 2 an embodiment of a multi-way value in'longitudinal section,

FIG. 3 is a front view partly in section of the metering device with the sample receptacles,

FIG. 4 illustrates an embodiment of the sealing,

FIG. 5 shows a modification of the arrangement of the sample receptacle, and

FIG. 6 a modification of the sealing.

The essence of the invention is best seen in FIG. .1, which shows one representative embodiment of design by which the principles outlined above can be realized.

As shown in FIG. 1, a plurality of sample capillary tubes 1 are successively connected through capillary ducts 2 and 3, shown in dotted lines, to multi-way valves which have as many peripheral necks as there areperipheral capillary. tubes 1. The peripheral necks are arranged to communicate with a central neck attachedtoduct 24 or 24', respectively.

The two multiway valves or. cocks 4 and 5, represented in FIG. 1 as six-way ones, may be arranged either on a single shaft or spindle, or may have the spindles separated from one another and mechanically interconnected by gears 6 and 7, or, alternately, by an additional connecting gear 8 in such a way that they perform identical motions. This motion may be generated by a separate electric drive on the principle of an electric impulse transmitted from a centralized programming unit. Alternately, this motion may also be generated by a ratchet mechanism, a ratchet 9 of this type of mechanism being moved stepwise through a corresponding angular distance by a pawl 10, This pawl is connected through an articulated joint to an oscillating arm 11, connected in its turn to a gear 12, engaging with

gears

13, 14, which serve to transmit a motion to two additional

hydraulic distributors

15 and 16. These

hydraulic distributors

15 and 16 may also be arranged on a single shaft and moved to and fro by one pitch distance by a corresponding electric drive of a known principle, not shown in FIG. 1, this drive being controlled from one centralized programming unit. The

hydraulic distributors

15 and 16 may occupy alternately one of two positions. In one of thesepositions, the pump 17 is connected with its delivery branch 18 through a port 19 provided in the rotatable core of a hydraulic changeover switch 15 to a connecting tubing 20 that communicates with one of the peripheralnecks of the hydraulic change-over switch 16. In the basic position of the rotatable core of the changeover switch 16, the port 21 establishes a communication between a tubing 20 and a tubing 22 which leads straight to the column 23. In the said basic position, both the upper multiway cock 4 and the lower multiway cock 5 are dis connected from thepressure circuit and the pump 17 delivers the eluent to the column 23. The communicating tubing 24 is, however, in the basic position inter connected, through an additional port 25 of the spindle of the hydraulic change-over switch 15, to the tubing 26 which leads to a mouthpiece, by means of which it is possible, using the mouth or another suitable suction device finely adjustable, to draw, by suction, the samples and covering buffers, together with the separating bubbles, into the respective reservoir or sample capillary tubes 1. Under this arrangement, each reservoir that is filled in the above described way has to be connected to the communicating tubing 24, and thereby also to the tubing 26, by means of a suitable positioning of the multiway cock 4. The bottom narrowed-down capillary mouth 27 has to be separated from the connecting member of the capillary tubing 3 in such a way as to make possible, through the narrow-down bottom capillary mouth 27, a drawing-in, by suction, of the sample and the covering buffers from the respective small vessels which are temporarily held under the reservoirs 1 in such a way as to situate the mouth 27 below the level of the corresponding fluid.

In FIG. 1 there is further shown one of the numerous possible design alternatives of a suitable connector to the capillary tubing 3. This tubing has one end flared in such a way that it cannot be pulled out of a bushing 28 made, for instance, of Teflon and fitted in its interior with a small sleeve 29 that can be made, for instance, of silicone rubber. The bottom of the bushing 28 bears against a supporting member 30, whereby a tight joint is obtained between the reservoir capillary tube 1 and the capillary tubing 3. In a similar way can be arranged the connection of the capillary tubing 2 to the reservoir capillary tube 1. The reservoir capillary tube 1 may lean here against an additional supporting member 31 which engages a expanded portion 32 of the bottom end of the full diameter of the reservoir capillary tube 1.

Consequently, in the above-described basic position of the hydraulic distributors l and 16 it is possible at any moment to fill all reservoir capillary tubes 1 which are left disconnected from the pressure circuit, with the exception of one single capillary tube. This is realized through an indexing of the hydraulic change-over switches 'and 16 to their second position of operation. In this take-off position, the delivery pipeline 18 leading from the pump 17 is switched over, through a port 19, to the communicating tubing 24, which in turn is connected to one of the peripheral necks of the multiway cock 4 and thereby also to the corresponding reservoir capillary tube 1. Through this connection to a pressure circuit the contents of the capillary tube 1 are forced through the capillary tubing 3 by way of the hydraulic change-over switch, through the capillary tubing 24" to the hydraulic change-over switch 16 and to the column 23. it is evident that the communicating conduit between the hydraulic change-over

switches

15 and 16 remains disconnectedv The entire equipment may remain in this functional position only for the time required for transportation of a sample, this being necessary particularly in those cases where more than one sample have been charged into the sample capillary tube 1. From there it is possible to transport only one of the samples charged, together with the corresponding buffers separated by little bubbles from the samples and from each other. Under no conditions may an additional sample be drawn in. If, on the other hand, only a single sample has been charged to the sample capillary tube 1, the entire equipment can remain in the aforesaid functional position for a longer time, and a thorough scouring of the entire equipment can be undertaken with a smaller amount of bubbles or even in their total absence. Such a scouring may serve to remove residues of the samples from the walls of the equipment and is realized by a limited amount of the buffer, the latter being, however, divided by bubbles, this arrangement being an efficient means against any kind of sticking of the fluid to the walls of the tubing during the throughflow, particularly if the inside walls have been rendered water-repellent.

If a number of samples have been charged to each of the capillary reservoirs, it is possible to use for their gradual evacuation the equipment, shown in FIG. 1, where during a motion of the spindles of the hydraulic changeover switches 15 and 16 and, consequently, also during a motion of the swinging arm 11, a switchingover of the two multiway cocks 4 and 5 to a next position will take place. With this arrangement there is, consequently, drawn only the lowermost sample from each reservoir capillary tube 1.

It is also possible to use an inverse procedure, according to which all samples are successively transported to the column from each reservoir capillary tube, while a switching-over of the multiway cocks 4 and 5 to the next position takes place. Only after the emptying of one capillary tube has been completed a switching-over of the two multi-way cocks to the next one may take place. This sequence of operations may be realized even while the equipment according to FIG. 1 has been maintained, by, raising, for instance, the

pawl 10 through a displacement ofa lifting member 10 v upward against the effort exerted by a spring 10" in such a way that the pawl 10 does then not engage the corresponding tooth of the ratchet 9 until a successive drawing of samples from the reservoir capillary tube 1 has been finished. More convenient than this mechanical method is another alternative according to which the motions of the hydraulic distributors l5 and 16 are directly influenced by a self-contained electric drive, the spindles of the multiway cocks 4 and 5 being shifted to their next positions without application of a mechanical connection between pawl 10 and ratchet 9 at the right moments according to orders transmitted in form of impulses by a centralized programming unit.

FIG. 2 shows an example of the design of multiway cocks, according to which the spindles 4 and 5 these cocks are merged into a single spindle 33, intermittently driven in the way described above. The spindle 33 is mounted in a body 34 by means of three packing rings (made advantageously of Teflon). These three packing

bushes

35, 36, 37 form, at the same time, the bearings that carry the spindle 33, and are spaced from one another by rigid metallic spacing tubes or rings 38 and 39; all these rings are, together with an additional metallic ring 40, forced together in the longitudinal direction by a packing set screw 41. The spindle 33 tightly fills the hollow interior of the body 34, being forced to the left in the direction indicated by an arrow 42, whereby a bearing of the spindle 33 against the bottom 43 of the hole in the body 34 is ensured.

In its left-hand extremity, the spindle 33 has a port drilled in an inclined position which enables the central capillary outlet tubing 45 to be connected to any one of the side tubings, one of the latter marked 46 being shown in FIG. 2. FIG. 2 shows how each of these two tubings is separately packed by an elastic sleeve 47 which is clamped, together with a ring 48, by a clamping screw 49. Thereby not only a packing of the corres ponding capillary tubing is obtained, but it is additionally secured against any accidental pulling-out. The tubing 46 corresponds to the capillary tubing 3 leading from the respective reservoir capillary tubes 1. All tubings situated after the reservoir capillary tube have to be interconnected without any dead spaces, since otherwise a mixing-up of the zones of concentration would take place during the transmission of a sample and the surrounding protective buffers. On the other hand, all tubings that supply the eluent to the reservoir capillary tube 1 need not necessarily be of a capillary type.

FIG. 2 further shows how the successive connection of the communicating tubing 24 to each of the capillary tubings 2 is arranged. Both these tubings are attached to the body 34 andpacked in a way similar to that of the

tubings

45 and 46. Through a port 50 the tubing 24 is connected to a void that is formed in the annulus 51 between the ring 39 and the spindle 33, the ring 39 having a peripheral groove connected by one or more drilled holes to the interior surface so as to warrant a connection to the port 50 in any position whatever. From the annulus 51, which in this way is permanently connected to the tubing 24, the eluent arrives through a port 52 bored to an inclined position, each time only at one of, for instance, the six uniformly spaced peripheral ports 53 which are connected to the individual capillary tubings 2 leading to the respective reservoir capillary tubes 1. In a similar way there may be arranged the spindles of the hydraulic change-over switches and 16. In this instance the design is simpler, since only the individual peripheral necks are connected which each time lay at the same level for each of the two hydraulic changeover switches.

FIG. 3 is a diagrammatic view of the reservoir and dosing equipment, a characteristic of which is that the individual reservoir capillary tubes 1, 1' etc., are attached in a common body that may be either compact or formed by two

strips

53, 54 with packing end faces ground to a smooth finish these faces being accurately contacted by the ends of sealed-on or otherwise attached individual reservoir capillary tubes. By the packing as represented in FIG. 4 the communicating

tubing

24 or 25 bears tightly, in each case, against the two ends of one particular reservoir capillary tube, thus acting in subtitution of the multiway cocks 4 and 5 according to FIG. 1. By the elimination of these multiway cocks the design is, consequently simplified though, of course, the exacting requirements required of a perfect packing must now be satisfied in the case of the said tight joints between the

tubing

24 or 25 and the two ends of the reservoir capillary tubes.

Instead of drawing the samples or the covering buffers to the respective sample tubes or reservoirs by suction during their filling by dipping the bottom ends of the reservoirs right up into the vessel that contains the sample or the buffers, this entire equipment is arranged, as shown in FIG. 3, in such a way that the tubing 25 is switched over, at the timeof filling of the individual reservoir capillary tubes, by means of a communicating port 55 provided in the spindle of the hydraulic change-over switch 16 to an intake tubing 56 by which the sample is drawn to the reservoir. Otherwise the operation of the equipment is identical with that described in FIG. 1. Accordingly, as shown in FIG. 3, the reservoir capillary tubes 1, 1', etc., perform, together with the

strips

53, 54, a step-by'step motion in the longitudinal direction. The same effect is, however, obtained by not having the individual capillary tubes arranged on the same level, but, instead, in the form of a circle, spaced atregular angular intervals, whereby the

strips

53, 54 will assume the shape of endwise discs. The equipment shown in FIG. 3 can thus be regarded as a development of a cylindrical surface into a plane. At any rate, thecapillary tubes alternate in their connections to the respective tubings in such a way that with a ratchet mechanism and the corresponding pawl the entire system of reservoirs is arranged so as to be advanced by one pitch each time.

The arrangement of the packings, which, with the exception of the functional position are not required to seal against any other pressure than the hydrostatic pressure of the sample column, is such that in the functional position the pressure circuit or its capillary tubing are secured also against high pressures.

An example of the design of a packing can be seen in FIG. 4. The communicating tubing 24 is here made of a hollow capillary steel needle, similar to an injection needle, the end of which is situated close above the top surface of a slat 53, into which the respective capillary reservoirs I, 1', etc., are sealed. By a clamp 57 the needle 24 is tightly held in position, after a clamping screw 58 has been tightened, the clamp 57 being positively attached to the frame of the equipment. One part of this frame is also formed by a non-movable plate 59 by which a seal 60 is pressed down so as to shut off tightly all orifices of the individual reservoir capillary tubes, with the exception of the one which is connected to the needle 24. A sealing of the needle guides also against the pressures required by the column is accomplished by a small packing sleeve 61, made of silicone rubber, Teflon or a similar material, attached to the bottom end of the needle 24. This little sleeve is held in position from without by a bushing 62, freely slipped upon the needle 24. The bushing 62 is compressed by a threaded joint made up of a nut 63 and a screw 64. Whenthese two elements are screwed together, a proportional compression of the narrow sleeve 61 is produced. In addition, the elastic seal 60 is also adequately compressed, this compression being produced in the vicinity of a tapered end of the bushing 62.

The individual reservoir capillary tubes 1, 1', etc., attached to

slats

53 and 54 can be substituted by calibrated smooth holes drilled in one solid piece of perspex" transparent plastic or similar material.

FIG. 5 diagrammatically shows equipment that can be constructed in the form of a longitudinally adjustable bar 61 with transversally reversible calibrated ports 62 that can desirably alternate with other ports 63 which are provided only for rinsing of the

capillary tubings

64 and 65. The evacuation of individual ports 62 with samples at the time of transportation of the samples to the column is performed under a pressure generated by the main pump 17 by way of the

tubings

18 and 24.

In this way a notable simplification of the hydraulic distributors is achieved in comparison with the former designs. The seal can, at the same time, be arranged with a far lower resistance to pressure, for instance, through a mere light pressing-on of the sealing strips'66 7 made of silicone rubber. One of the numerous possibilities of a practical realization of this type of equipment is illustrated in FIG. 6 in a transverse sectional view at the outlet end of the intake tubing 65. The sealing strip 66 is attached, for instance, by an adhesive to a stationary profiled slat 67, providing, in this position, with its narrow surface a seal to the upper end face of the body 61 with ports 62. The entire equipment may be arranged not only for a linear displacement, but advantageously also for a rotary motion, in either case a motion of an intermittent character.

I claim:

1. A method of sequentially chromatographically analyzing a plurality of liquid samples, comprising:

disposing each of said samples in a respective bore wherein said sample is retained;

sequentially disposing each bore between an inlet fitting coupled to a source of eluting fluid and an outlet fitting coupled to the inlet of a chromatography column, and passing eluting fluid through said respective bore to convey said respective liquid sample into said column; and inhibiting the flow of eluent fluid to said inlet fitting while a bore is being disposed between said inlet and outlet fittings.

2. Automatic sample loading apparatus for a chromatography column having an inlet means, comprising in combination pump means injecting an eluting fluid into said column;

conduit means for the eluting fluid coupling said pump means with said column;

at least two capillary sample receptacles;

means delivering sample into each of said receptacles;

hydraulic switching means within said conduit means controlling the eluting fluid to flow from said pump means into the column either directly or through one of said receptacles transferring a respective sample.

3. Automatic sample loading apparatus for a chromatography column having an inlet means, comprising in combination a pressure pump for the eluent;

a chromatographic column;

at least two tubular capillary sample receptacles each having at its ends a first and a second opening, respectively;

a first and a second conduit each leading into one of the first and the second openings, respectively;

a first and a second multiway valve governing said first and said second conduit, respectively, each multiway valve having at least one outlet assigned to one sample receptacle;

a first hydraulic distributing valve governing the flow of eluent coming from the pressure pump and a second distributing valve governing the flow into the chromatographic column, said first and second distributing valve conductively associated with each other and each with one multiway valve;

said distributing valves in a first position connecting the pressure pump directly with the column bypassing any sample receptacle, and in a second position directing the flow of eluent from the pressure pump into and through one of the sample receptacles to transfer the sample therefrom into the column; suction means governed by the first distributing valve drawing a sample into one sample receptacle during the first position of the distributing valves; and

actuating means coordinating said multiway valves and said distributing valves for complementing action during said first and second position of the distributing valves.

4. Automatic sample loading apparatus for a chromatography column having an inlet means, comprising a pressure pump for the eluting fluid and a first conduit leading therefrom;

a chromatographic column and a second conduit leading thereinto;

at least two capillary sample receptacles each having at its ends a first and a second opening, respectively;

a support for said sample receptacles reciprocable in a direction substantially perpendicular to their longitudinal axes;

means feeding a sample into the receptacles;

a first and a second hydraulic distributing valve operatively associated with each other and turnable into a first and a second position;

in the first position the distributing valves establishing a direct communication of the pump with the column to deliver eluent thereinto, and in the second position connecting the pump with the column over and through one sample receptacle to directly carry. the sample therefrom into the column by the flow of eluting fluid originating in the pump.

5. Automatic sample loading apparatus for a chromatography column comprising sample support means having a plurality of bores in spaced-apart relationship and each containing a sample to be introduced into said chromatography column,

first and second fluid coupling means disposed adjacent to said support means,

means for intermittently moving said sample support means to successively dispose each of said bores individually in flow communication with said first and second fluid coupling means, means for directing eluent under pressure to said first fluid coupling means when a sample is to be transferred to said chromatography column and while a bore is positioned in flow communication with said first and second fluid coupling means,

means for connecting said second fluid coupling means to said chromatography column, at least while said eluent is being directed to said first fluid coupling means, and

means for introducing a sample into a bore while positioned between said first and second fluid coupling means.

6. Automatic sample loading apparatus according to claim 5 wherein said directing means further includes eluent fluid pumping means, and additional means for connecting said pumping means in fluid flow communication with said chromatography column along said first and second fluid coupling means and a bore positioned in flow communication therewith.

7. Automatic sample loading apparatus according to claim 5 wherein said directing means includes further means for connecting said pump means to said chromatography column in bypass of said first and second fluid coupling means while said introducing means is operative to introduce a sample into a bore disposed between said first and said second fluid coupling means.

8. Automatic sample loading apparatus according to claim 5 wherein said introducing means is operative to introduce a sample into a bore disposed between said first and second fluid coupling means by suction.

9. Automatic sample loading apparatus according to claim wherein said introducing means is operative to introduce a sample and a covering buffer, separated by an air bubble, into a bore disposed between said first and second fluid coupling means.

10. Apparatus according to claim 5 wherein each respective one of said plurality of bores is adapted to receive different unique liquid samples.

11. Automatic sample loading apparatus for a chromatography column comprising a chromatography column,

pumping means for injecting eluent fluid into said chromatography column,

first valving means having an inlet and first and second outlets, and a second valving means having a first and second inlet and an outlet,

a first pressure line leading from said pumping means to said inlet of said first valing means, and a second pressure line leading from said outlet of said second valving means and connected to said chromatography column,

a third pressure line leading from the second outlet of said first valving means to said first input of said second valving means whereby said pumping means is connectable directly to said chromatography column along said first and second valving means,

sample support means having a plurality of sample containing bores and first and second fluid coupling means, means for intermittently moving said sample support means to sequentially dispose each of said bores in flow communication with said first and second coupling means, fourth pressure line connecting said first coupling means to said first output of said first valving means, and a fifth pressure line connecting said second coupling means to said second input of said second valving means, and

said first and second valving means being operative to connect said pumping means to said chromatography column along said first and second coupling means when a bore is disposed therebetween whereby a sample contained in said disposed bore is discharged into said chromatography column by said pumping means.

12. Automatic sample loading apparatus as defined in claim 11 including further means for introducing sample into a bore disposed between said firstand second coupling means; said further means being operative while said pumping means is connected directly to said chromatography column along said first and second valving means and said first pressure line.

13. Apparatus for automatically loading samples for analysis on to a chromatography column comprising a transfer member movable along a path, a plurality of sample locating chambers located in a spaced relationship on said transfer member and extending through said member, a fluid inlet duct and a fluid outlet duct, said fluid outlet duct leading to said column, said ducts being located, relative to said transfer member to be connected with successive chambers, means for sealing both ducts to opposite sides of a fluid passageway through a given chamber with which the ducts are connected, such that fluid can flow from said inlet duct through the given chamber and through the outlet duct, and means for stepwise moving the transfer member such that each chamber is, in turn, simultaneously registerable with said inlet and outlet ducts.

14. Apparatus for automatically loading samples for analysis on to a chromatography column comprising a transfer member movable along a path, a plurality of apertures in a spaced relationship in said member and extending through said member, sample support means for locating and supporting samplein each aperture, means for stepwise moving the member such that each sample support means in each aperture is held in exclusive register with fluid inlet and outlet ducts and fluid sealing means between the member and each of the said ducts for sealing the ducts to opposite sides of a fluid passageway through the sample support means in exclusive register with the ducts, such that fluids flow from said inlet duct through the sample support means and through the outlet duct.

15. Apparatus for automatically loading samples for analysis onto a chromatography column comprising a transfer member having a plurality of sample locating chambers located in spaced relationship in said transfer member, each chamber being in the form of a bore extending through the transfer member, a fluid flow assembly including a fluid inlet duct and a fluid outlet duct, the two said ducts being located to be simultaneously registerable with a given chamber sealing the two ducts to the chamber such that fluid can flow from said inlet duct through the chamber to said outlet duct, said transfer member and said fluid flow assembly being relatively movable such that the two said ducts can register, in turn, with successive chambers of said transfer member.

Claims

1. A method of sequentially chromatographically analyzing a plurality of liquid samples, comprising: disposing each of said samples in a respective bore wherein said sample is retained; sequentially disposing each bore between an inlet fitting coupled to a source of eluting fluid and an outlet fitting coupled to the inlet of a chromatography column, and passing eluting fluid through said respective bore to convey said respective liquid sample into said column; and inhibiting the flow of eluent fluid to said inlet fitting while a bore is being disposed between said inlet and outlet fittings.

2. Automatic sample loading apparatus for a chromatography column having an inlet means, comprising in combination pump means injecting an eluting fluid into said column; conduit means for the eluting fluid coupling said pump means with said column; at least two capillary sample receptacles; means delivering sample into each of said receptacles; hydraulic switching means within said conduit means controlling the eluting fluid to flow from said pump means into the column either directly or through one of said receptacles transferring a respective sample.

3. Automatic sample loading apparatus for a chromatography column having an inlet means, comprising in combination a pressure pump for the eluent; a chromatographic column; at least two tubular capillary sample receptacles each having at its ends a first and a second opening, respectively; a first and a second conduit each leading into one of the first and the second openings, respectively; a first and a second multiway valve governing said first and said second conduit, respectively, each multiway valve having at least one outlet assigned to one sample receptacle; a first hydraulic distributing valve governing the flow of eluent coming from the pressure pump and a second distributing valve governing the flow into the chromatographic column, said first and second distributing valve conductively associated with each other and each with one multiway valve; said distributing valves in a first position connecting the pressure pump directly with the column bypassing any sample receptacle, and in a second position directing the flow of eluent from the pressure pump into and through one of the sample receptacles to transfer the sample therefrom into the column; suction means governed by the first distributing valve drawing a sample into one sample receptacle during the first position of the distributing valves; and actuating means coordinating said multiway valves and said distributing valves for complementing action during said first and second position of the distributing valves.

4. Automatic sample loading apparatus for a chromatography column having an inlet means, comprising a pressure pump for the eluting fluid and a first conduit leading therefrom; a chromatographic column and a second conduit leading thereinto; at least two capillary sample receptacles each having at its ends a first and a second opening, respectively; a support for said sample receptacles reciprocable in a direction substantially perpendicular to their longitudinal axes; means feeding a sample into the receptacles; a first and a second hydraulic distributing valve operatively associated with each other and turnable into a first and a second position; in the first position the distributing valves establishing a direct communication of the pump with the column to deliver eluent thereinto, and in the second position connecting the pump with the column over and through one sample receptacle to directly carry the sample therefrom into the column by the flow of eluting fluid originating in the pump.

5. Automatic sample loading apparatus for a chromatography column comprising sample support means having a plurality of bores in spaced-apart relationship and each containing a sample to be introduced into said chromatography column, first and second fluid coupling means disposed adjacent to said support means, means for intermittently moving said sample support means to successively dispose each of said bores individually in flow communication with said first and second fluid coupling means, means for directing eluent under pressure to said first fluid coupling means when a sample is to be transferred to said chromatography column and while a bore is positioned in flow communication with said first and second fluid coupling means, means for connecting said second fluid coupling means to said chromatography column, at least while said eluent is being directed to said first fluid coupling means, and means for introducing a sample into a bore while positioned between said first and second fluid coupling means.

9. Automatic sample loading apparatus according to claim 5 wherein said introducing means is operative to introduce a sample and a covering buffer, separated by an air bubble, into a bore disposed between said first and second fluid coupling means.

11. Automatic sample loading apparatus for a chromatography column comprising a chromatography column, pumping means for injecting eluent fluid into said chromatography column, first valving means having an inlet and first and second outlets, and a second valving means having a first and second inlet and an outlet, a first pressure line leading from said pumping means to said inlet of said first valing means, and a second pressure line leading from said outlet of said second valving means and connected to said chromatography column, a third pressure line leading from the second outlet of said first valving means to said first input of said second valving means whereby said pumping means is connectable directly to said chromatography column along said first and second valving means, sample support means having a plurality of sample containing bores and first and second fluid coupling means, means for intermittently moving said sample support means to sequentially dispose each of said bores in flow communication with said first and second coupling means, a fourth pressure line connecting said first coupling means to said first output of said first valving means, and a fifth pressure line connecting said second coupling means to said second input of said second valving means, and said first and second valving means being operative to connect said pumping means to said chromatography column along said first and second coupling means when a bore is disposed therebetween whereby a sample contained in said disposed bore is discharged into said chromatography column by said pumping means.

12. Automatic sample loading apparatus as defined in claim 11 including further means for introducing sample into a bore disposed between said first and second coupling means; said further means being operative while said pumping means is connected directly to said chromatography column along said first and second valving means and said first pressure line.

14. Apparatus for automatically loading samples for analysis on to a chromatography column comprising a transfer member movable along a path, a plurality of apertures in a spaced relationship in said member and extending through said member, sample support means for locating and supporting sample in eAch aperture, means for stepwise moving the member such that each sample support means in each aperture is held in exclusive register with fluid inlet and outlet ducts and fluid sealing means between the member and each of the said ducts for sealing the ducts to opposite sides of a fluid passageway through the sample support means in exclusive register with the ducts, such that fluids flow from said inlet duct through the sample support means and through the outlet duct.