US3766884A

US3766884A - Apparatus for sample application in thin layer and paper chromatography

Info

Publication number: US3766884A
Application number: US00157117A
Authority: US
Inventors: A Rosenthal
Original assignee: Long Island Jewish Medical Center
Current assignee: LONG ISLAND JEWISH MEDICAL CENTER US; Long Island Jewish Medical Center
Priority date: 1971-06-28
Filing date: 1971-06-28
Publication date: 1973-10-23
Anticipated expiration: 1990-10-23

Abstract

An apparatus for producing spots of specimens of material on a plate having a thin layer adsorbing surface, the specimens being dissolved in a diluting solvent for chromatographic analysis, with a plurality of units, each one of the units comprising a glass tube which is filled with a specimen through a funnel-like glass filling tube projecting perpendicularly from the upper surface of the specimen tube, the latter also having an open front and which is stoppered or otherwise covered by a teflon or other inert plug through which passes a capillary tube, the capillary tube having a bent front end protruding from the open front end of the glass tube so that the end of the capillary is very close to the adsorbing surface of the plate, and an air tube above the front end of the capillary which may be adjustably set to blow a low-pressure air stream onto the specimen emanating from the capillary to evaporate the solvent, thereby forming a spot of the specimen on the thin-layer adsorbing surface of the plate.

Description

[451 Oct. 23, 1973 United States Patent [191 Rosenthal [54] APPARATUS FOR SAMPLE APPLICATION IN THIN LAYER AND PAPER CHROMATOGRAPHY wrs, mccmh.. ,rwth rmfnu ue SSVf n l0 .ego m.mSy .limmam C ewuum Wdmm fmdp Twnwwaa t Cwmmm Msmww nehv Tntls, S.Ia0.l BC uws Amsiw. O.mda ...Vgn Pa.ma rhec mbm wper. mam@ a .It wmmm nr h Amc k, r a l. P e i w mm H M, k w m m N wp n. Je .M d .h dy t nH m h kw R MUN r 09 u.Lh.r mY en n.he AN TC v .m A M M 7 7 Mmmm as ma 3. 76E-1884 SHEEY l UF 2 JMW/WMM@ Jew/Paw `ATTORNEYS `one another on the adsorbent APPARATUS FOR SAMPLE APPLICATION IN THIN LAYER AND PAPER CHROMATOGRAPHY BACKGROUND OF THE INVENTION The invention relates generally to medicomechanical apparatus and particularly to apparatus for simultaneously preparing a plurality of specimens, especially for chromatographic analysis.

Various devices for producing spots for chromatographic analysis are known, some being built on an experimental laboratory basis in universities, some others being commercially produced. The known devices may be divided into the two main groups, one to produce specimens in streak form and the other to form individual spots The objective in making streaks is usually purification of a mixture for preparative purposes, while spot-making devices (as the presently described one) are used to facilitate qualitative or quantitative analysis of the chromatographically-separated materials. All prior art devices have several features in common. Either they are hand-operated, which is slow, tedious work,.tying up laboratory personnel for the prep-V aration of the specimens and delaying the chromatographic analysis, or else they employ devices such as bellows, pumps, or other `motorized devices which make them bulky and/or expensive and may expose the sample solutions to contamination from pump tubing. The non-motorized devices apply `liquid to the spots discretely rather than continuously; since the samples to be analyzed are diluted by a solvent, it is obvious that the solvent of each one of these spots has to be evaporated before another portion of solution can be applied to the spot, until a comlete spot is formed which contains a sufficient quantity of material for the chormatographic analysis. Another common feature found in the prior art is having either the base-plate on which the spots are to be formed, or the pipet or capillary, Amove to obtain more than one spot or streak. Various operations are known to fill the pipettes or capillaries, all of which are cumbersome, V expensive and/or timeconsuming. All known devices have been built tobe operated by skilled personnel who have to devote theirV full attention tothe process of preparing the spots, and since thisoperation is strictly under manual control, it is more likelythan not that the sizes and thicknesses of the spots obtained, as well as their positions relative to base, will not be uniform and consistent. l ,Y i

The problems of timeand labor-saving production of the spots and of a more predictable and reliable conples are dissolved by a solvent (e.g., chloroform) which has an adequate and desirable rate of evaporation. Specimens of the magnitude of l-2 ml are taken and deposited in the form of spots on the adsorbent surface by a continuous process, during which the solvent is continuously evaporated. The final spot contains, therefore, the entire quantity of the solids of the sample and yet does not have a size larger than 0.5 to 0.75 cm.

`The invention thus serves simultaneously to concentrate the specimen and apply it as a compact spot to a thin-layer plate, in preparation for chromatographic separation and analysis. Small, easily refillable reservoirs for the specimens are provided and capillary tubes are used to take the solution out of the reservoirs for continuous deposit on the support plate on the same spot. A supply of air under low pressure, which may or may not be heated, is directed down by way of a nozzle on top of the discharge end of the capillary tube. This flow of low-pressure air envelops the end of the capillary without causing an air turbulence, evaporating at the same time the solvent and holding the forming spot to its desired diameter. This feature enables the ar rangement of a plurality of capillaries side-by-side, which can thus be used simultaneously. Since the support plate with the adsorbent surface layer has the standard width of 8 inches, the arrangement of 8 capillaries at distances of 1 inch from one another is easily feasible, without spots running into one another.

Objects and advantages of the invention will be set forth in part hereafter and in part will be obvious hereb from or may be learned by practicing the invention, the

' consisting of ya sizable quantity of a sample junder sistency of quality of these' spots, are intended to be i solved-by this invention.

SUMMARY oF THE nvvENTioN The invention consistsin such novel features, construction arrangements, combinations of parts and improvements as may be shownand describedin connection with the apparatus herein disclosed by way of example only and as illustrative of a preferred embodi-` coninuous evaporation ofthe solvent of the sample.

A further object of the invention is to provide an apparatus by which reliably reproducible results can be obtained without continuous manual operation of the apparatus.

Furthermore, it is an object of rthe invention to provide an apparatus which can be operated expeditiously and without continuous supervision.

Yet another object `of the invention is to provide an apparatus which is of simple structure and can be eco nomically produced.

Various further and more specific purposes, features and advantages will clearly appear from the detailed description given below taken in connection with the accompanying drawingwhich forms part of this specification and illustrates merely by way of example one embodiment of the apparatus of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the following description and in the claims, parts will be identified by specific names for convenience,

i but such names are intended to be as generic in their application to similar parts as the art will permit. Like reference characters denote like parts in the figures of the drawing, in which FIG. 1 is an isometric perspective view of the apparatus of the invention;

FIG. 2 is a part of the apparatus having the reservoir tube for the specimen and the support arm which the socket for the conventional ball-and-socket universal joint;

FIG. 3 shows the holder for the air tube, having the ball-shaped end constituting the counterpart for the socket shown in FIG. 2.k

FIG. 4 shows the air tube with the flared nozzle end;

FIG. 5 is a plan view of the capillary tube which fits through the teflon plug which is seated firmly in the reservoir tube shown in FIG. 2; and

FIG. 6 is a side view of the capillary shown in FIG. 5.

DESCRIPTION `OF THE PREFERRED EMBODIMENT Referring now in more detail to the drawing illustrating a preferred embodiment by which the invention may be realized, there is the complete apparatus of the invention shown in FIGS. 1, identified by the general numeral 10.A The component parts are mounted on a base 11, preferably made of a corrosion-proof material. A plurality of vertical posts l2 (eight are shown in the Figure) are fixedly erected on base 1l, spaced apart in equal intervals in side-by-side relationship in a straight row. Conventional spring clips 13 are attached to posts l2 to hold the support parts 14 for the tube-like reservoirs 15 in place. Support parts 14, which may be of glass, comprise an upright member 16, the tube-like reservoir 15 affixed to the lower end of member 16 and inclined slightly'upward, anda support arm y17 which is affixed to the upper end of member 16 at right angle thereto. The free end of support arm 17 is shaped as a socket 18 of a universal ball joint,- into which the ballshaped e'nd 19`of the holder 20 for the air tube 2l fits. Ball-shaped end 19 is the end of a short arm 22 which is affixed to a tube 23 at right angle thereto." Ball end 19 is held in place in socket 18 by a conventional spherical-joint spring clamp 24. Airtube 21 fits freely in glass tube 23 and is held in place therein by short rubber sleeves'25 in` such manner that it is easily adjust- 4 horizontal and has a short stopper 28 plugging the front end thereof. The-stopper 28 consists preferably of a solid piece of inert plastic (e.g. teflon or polyethylene) which securely covers thefront end of reservoir 15, but is removable. Capillary 31 passes through stopper 28 through an opening therein small enough to prevent lateralmovement of capillary 3l in an air stream. This arrangement holds capillary 31 securely in place. A small funnel-like tube 39 projects from the upper surface of tube l5 just in front of its center through which reservoir l5 is filled without taking it out of the apparatus. Capillary 31 consists preferably of a piece of stainless steel hypodermic needle material. A short piece of an inert plastic capillary tube 32 is attached to the front end of capillary 31. Plastic tube 32 is bent downward at right angle so that the end 33 thereof can be set very close to the adsorbent surface coating of the thin layer chromatographic plate 34 which is placed on base 1li underneath ends 33, without the risk of damaging this coating. Conventional thin-layer plate 34 consists of a piece of thin glass or of a suitable plastic, the surface of which is very evenly coated with an adsorbent material such as silica gel, in which the line of spots of the specimens to be chromatographically anaylzed is formed. Behind the line of posts l2 is a manifold 35 mounted on base ll, and air hoses 36 are attached to the upper ends of air tubes 2l, leading therefrom to manifold 35 which is, in turn, connected by a feeding air hose 37 to a conventional source of compressed air under low pressure. Laboratory-style Hoffman screw clamps 38 are arranged on air hoses 36 for a final adjustment of air supply to air tubes 2l. It is not absolutely necessary to heat the air, but a provision may be made to increase the temperature of the air above the ambient room temperature by conventional heating means (e.g. by encirling the glass manifold with a heating coil, by directing infrared light at the line of forming spots, or by having the base 1l be the top surface of a hot plate).

The apparatus is operated as follows:

The support parts 14 are vertically adjusted on posts 12 so that ends 33 of plastic capillaries 32 are very close to the coated surface of the chromatographic plate 34 which has been placed on base l1 so that the row of the ends 33 is approximately l inch away from the edge of the plate. Air tubes 2l are set vertically above the ends of the capillaries and are adjusted by the universal joint to a position where the flared nozzles 27 are above the ends of the capillaries. In the meantime, samples to be analyzed have been prepared by dissolving them in a solvent, for example, chloroform. Low pressure air is now turned on and the flow of air is individually adjusted by means of hose clamps 38. Quantities of the diluted samples, generally 2 ml each, are filled through hole 39 into reservoir tubes l5. Since tubes 15 are slightly inclined from the horizontal, the liquid will not flow onto the plastic Stoppers 28, but will pass slowly by the capillary action through capillaries 31, and since ends 33 of the plastic capillaries 32 are slightly lower than the rear end of capillaries 3l in reservoir tubes 15, a siphoning effect also takes place in feeding the liquid out of the reservoirs through the capillaries. The slow outflow of the samples will form relatively small spots as long as the air flowing out of flared nozzles will evaporate the, solvent instantaneously, continuously preventing thereby a spreading of the liquid in the absorbent coating. The air nozzles are eventually adjusted to a desired position so that spots of approximately 0.5 to 0.75 cm diameter will result. The process continuesfully automatically until the entire contents of the reservoirs are spent and the solids of the samples are accumulated inthe spots.v The reservoirs may be washed with fresh portions of solvent, if desired, and the wash solution added to the original spot by the same means used in thel application of the latter. The plate with the spots thereon is now taken off the base v and subjected to the conventional chromatographic analysis. The accuracy of the automatedvprocess is far greaterand more consistent than one of a tedious manual operation, and better comparable analytic results can be obtained.

It is understood that the present invention may also be used similarly for the application of sample spots for of the invention, that various other changes and moditications may be made without departing from the spirit l of the invention.

What is claimed is:

l. A spot applicator unit for thin layer and paper chromatography, which comprises a. reservoir means for holding a measured amount of a liquid sample, said reservoir means havinginlet means for filling said reservoir means and capillary tube outlet means for siphoning said measured amount of liquid sample out of said reservoir means, said capillary tube outlet means having a discharge end outside the reservoir means and below the level of a liquid sample in said reservoir means;

b. air supply means for flowing a stream of low pressure air to evaporate solvent from said liquid sample siphoned out of said reservoir means; and

c. support means for supporting said reservoir means and said air supply means with said air supply means arranged to flow air over a liquid sample discharged from said discharge end, said support means including adusting means for adjusting the position of said air supply means relative to said discharge end of said capillary outlet means thereby to control the rate of evaporation of solvent from `said liquid sample siphoned out of said reservoir means.

2. The applicator unit according to claim ll, wherein said air supply means has a flared outlet end positioned adjacent said discharge end, the position of said flared outlet end being adjustable by said adjusting means.

3. `The applicator unit according to claim l2, whereinv said reservoir means has an elongated body portion, and said capillary outlet means comprises a capillary tube having a first part thereof inside said elongated body portion and in communication with a liquid sample in said elongated body portion, and said discharge end being provided by a second part of the capillary tube positioned outside of saidv bodyportion and arranged transverse to said elongated body portion.

4. The applicator unit according` to claim 3, wherein f said second part of said capillary tube is substantially perpendicular'to said elongated body portion.

5. The applicator unit according to claim 3, wherein and said second part is of an insert plastic secured to said tirst part.

6. The applicator unit according to claim 3, wherein said capillary tube is removably mounted in said elongated body portion.

7'. `The applicator unit according to claim 1, wherein said air supply means comprises air tiow controlv means.

, d. The applicator unit according to claim 1, wherein said air supply means comprises means for supplying heated air.

said tirst part of said capillary tube is of stainless steel having a tirst part inside the reservoir meansand extending to the lowest part of said reservoir means and a second part outside the reservoir means and extending below the level of said lowest part of said reservoir means, said capillary tube outlet means being thus operable to siphon out the entire content of liquid sample in said reservoir.

lill. Apparatus for analysis of multiple samples by thin layer and paper chromatography, which comprises A) a base for supporting a chromatographic paper or plate; B) a plurality of spot applicator units mounted in side-byside relationship on said base, each spot applicator unit comprising a. reservoir means for holding a measured amount of a liquid sample, said reservoir means having inlet means for filling said reservoir means and capillary tube outlet means for siphoning said measured amount of liquid sample out of `said reservoir means and onto a paper or plate on said base,isaid capillary tube outlet means having a discharge end outside the reservoir means and below the level of a liquid sample in said reservoir means;

b. air supply means for flowing a stream of low pressure air to evaporate solvent from said liquid sample siphoned out of said reservoir means and onto a paper or plate on said base; and

'c. support means for supporting said reservoir means and said air supply means with said air supply means arranged to tlow `air over a liquid sample discharged from said discharge end, said support means including adjusting means for adjusting the position of said air supply means relative to said discharge end of said capillary outlet means thereby to control the rate of evaporation of solventfrom said liquid sample siphoned out of said reservoir means; and C) the support means of saidapplicator units being mounted in spaced realtionship on said base. l

12. Apparatus according to claim l1, wherein said air supply means has aportion extending substantially vertically, said vertical portion having a flared outlet end positioned adjacent said discharge "end, the position of said flared outlet end being adjustable by said adjusting means. l

13. Apparatus according to claim 12, wherein said reservoir means has an elongated body portion slightly inclined to the horizontal, and said capillary outlet means comprises a capillary tube having a rst part l thereof inside said elongated body pprtion and in communication with a liquid sample in said elongated body portion, and said discharge end lbeing provided by a v second part of the capillary tube positioned outside of i posts are spaced apart from one another at regular intervals in a straight line.

18. Apparatus according to claim 11, wherein said adjusting means comprises a ball and socket universal joint.

19. Apparatus according to claim l 1, wherein said air supply means comprises an air tube for each unit, an air manifold, flexible air hoses connecing said air tubes to said manifold, and air flow control means on said air hoses.

20. Apparatus according to claim 19, wherein said air flow control means consists of screw clamps.

2l. Apparatus according to Claim 19, wherein said air supply means comprise means to heat said manifold.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,766,884 Dated October 23, 1973 Invented@ Arthur Rosenthal ,p It is certified that error appears in the above-identified patent and that said Letters Patentare hereby corrected as shown below:

Cancel claim 10 and insert the following: i l0 The applicator unit according to claim 3,

wherein said inlet means for filling said reservoir is provided by a vertical funnel-like tube projecting upwardly from said elongated body portion; and plug means are provided in one end of said elongated body portion, said capillary tube passing through .said plug means 24 Apparatus according to claim 13, wherein said" inlet means for filling said reservoir is provided by a vertical funnel-like tube projecting upwardly from said elongated body portion; and plug means are provided in one end of said elongated body portion, said capillary tube passing through sai plug means.

Claim 17, fline 2, "posts" should read support means Signed and sealed this 17th day of September `1974.

(SEAL) "Attest:

t McCOY M. GIBSON JR. C. MARSHALL DANN y y Attestng Officer Commissioner of Patents FORM P01050 (10'69) UscoMM-Dc coen-ps9 U.S, GOVERNMENT PRINTJNG OFFCE: |959 0-36631,

Claims

1. A spot applicator unit for thin layer and paper chromatography, which comprises a. reservoir means for holding a measured amount of a liquid sample, said reservoir means having inlet means for filling said reservoir means and capillary tube outlet means for siphoning said measured amount of liquid sample out of said reservoir means, said capillary tube outlet means having a discharge end outside the reservoir means and below the level of a liquid sample in said reservoir means; b. air supply means for flowing a stream of low pressure air to evaporate solvent from said liquid sample siphoned out of said reservoir means; and c. support means for supporting said reservoir means and said air supply means with said air supply meAns arranged to flow air over a liquid sample discharged from said discharge end, said support means including adusting means for adjusting the position of said air supply means relative to said discharge end of said capillary outlet means thereby to control the rate of evaporation of solvent from said liquid sample siphoned out of said reservoir means.

2. The applicator unit according to claim 1, wherein said air supply means has a flared outlet end positioned adjacent said discharge end, the position of said flared outlet end being adjustable by said adjusting means.

3. The applicator unit according to claim 2, wherein said reservoir means has an elongated body portion, and said capillary outlet means comprises a capillary tube having a first part thereof inside said elongated body portion and in communication with a liquid sample in said elongated body portion, and said discharge end being provided by a second part of the capillary tube positioned outside of said body portion and arranged transverse to said elongated body portion.

4. The applicator unit according to claim 3, wherein said second part of said capillary tube is substantially perpendicular to said elongated body portion.

5. The applicator unit according to claim 3, wherein said first part of said capillary tube is of stainless steel and said second part is of an insert plastic secured to said first part.

7. The applicator unit according to claim 1, wherein said air supply means comprises air flow control means.

8. The applicator unit according to claim 1, wherein said air supply means comprises means for supplying heated air.

9. The applicator unit according to claim 1, wherein said capillary tube outlet means comprises a capillary tube having a first part inside the reservoir means and extending to the lowest part of said reservoir means and a second part outside the reservoir means and extending below the level of said lowest part of said reservoir means, said capillary tube outlet means being thus operable to siphon out the entire content of liquid sample in said reservoir.

10. The applicator unit according to claim 3. wherein said inlet means for filling said reservoir is provided by a vertical funnel-like tube projecting upwardly from said elongated body portion; and plug means are provided in one end of said elongated body portion, said capillary tube passing through said plug means.

11. Apparatus for analysis of multiple samples by thin layer and paper chromatography, which comprises A) a base for supporting a chromatographic paper or plate; B) a plurality of spot applicator units mounted in side-by-side relationship on said base, each spot applicator unit comprising a. reservoir means for holding a measured amount of a liquid sample, said reservoir means having inlet means for filling said reservoir means and capillary tube outlet means for siphoning said measured amount of liquid sample out of said reservoir means and onto a paper or plate on said base, said capillary tube outlet means having a discharge end outside the reservoir means and below the level of a liquid sample in said reservoir means; b. air supply means for flowing a stream of low pressure air to evaporate solvent from said liquid sample siphoned out of said reservoir means and onto a paper or plate on said base; and c. support means for supporting said reservoir means and said air supply means with said air supply means arranged to flow air over a liquid sample discharged from said discharge end, said support means including adjusting means for adjusting the position of said air supply means relative to said discharge end of said capillary outlet means thereby to control the rate of evaporation of solvent from said liquid sample siphoned out of said reservoir means; and C) the support means of said applicator units being mounted in spaced realtionshIp on said base.

12. Apparatus according to claim 11, wherein said air supply means has a portion extending substantially vertically, said vertical portion having a flared outlet end positioned adjacent said discharge end, the position of said flared outlet end being adjustable by said adjusting means.

13. Apparatus according to claim 12, wherein said reservoir means has an elongated body portion slightly inclined to the horizontal, and said capillary outlet means comprises a capillary tube having a first part thereof inside said elongated body pprtion and in communication with a liquid sample in said elongated body portion, and said discharge end being provided by a second part of the capillary tube positioned outside of said body portion and extending downwardly.

14. Apparatus according to claim 13, wherein said second part of said capillary tube is substantially perpendicular to said elongated body portion.

15. Apparatus according to claim 13, wherein said first part of said capillary tube is of stainless steel and said second part is of an inert plastic secured to said first part.

16. Apparatus according to claim 13, wherein said capillary tube is removably mounted in said elongated body portion.

17. Apparatus according to claim 11, wherein said posts are spaced apart from one another at regular intervals in a straight line.

19. Apparatus according to claim 11, wherein said air supply means comprises an air tube for each unit, an air manifold, flexible air hoses connecting said air tubes to said manifold, and air flow control means on said air hoses.

20. Apparatus according to claim 11, wherein said air flow control means consists of screw clamps.

21. Apparatus according to claim 11, wherein said air supply means comprise means to heat said manifold.

22. Apparatus according to claim 11, including and means to heat said base.

23. Apparatus according to claim 11, wherein said capillary tube outlet means comprises a capillary tube having a first part inside the reservoir means and extending to the lowest part of said reservoir means and a second part outside the reservoir means and extending below the level of said lowest part of said reservoir means, said capillary tube outlet means being thus operable to siphon out the entire content of liquid sample in said reservoir.

24. Apparatus according to claim 13, wherein said inlet means for filling said reservoir is provided by a vertical funnel-like tube projecting upwardly from said elongated body portion; and plug means are provided in one end of said elongated body portion, said capillary tube passing through said plug means.