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Publication numberUS3780700 A
Publication typeGrant
Publication dateDec 25, 1973
Filing dateOct 14, 1971
Priority dateOct 14, 1971
Publication numberUS 3780700 A, US 3780700A, US-A-3780700, US3780700 A, US3780700A
InventorsLafleur B, O Brien R
Original AssigneeEastman Kodak Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Template for thin layer chromatography samples
US 3780700 A
Abstract
A template for holding a chromatographic sheet while permitting the application of a series of liquid samples rapidly, and on a well defined area of fixed size, comprises a base plate adapted to receive a chromatographic sheet on its surface, an applicator plate mating with the base plate and adapted to lie on top of the sheet, and means for clamping the parts together to hold the sheet in place. The applicator plate and the base plate are hinged together and provided with latches for clamping them together. To provide wells for receiving liquid samples, the applicator plate has a plurality of bores therethrough within which are pressed plastic bushings for engaging the chromatographic sheet without damaging its delicate surface. Also, two stop springs ease the movement of the applicator plate into register with the base plate so as to avoid damage to the chromatographic sheet. The base plate is provided with an abutment against which an edge of a chromatographic sheet is precisely positioned. The hinges are readily disengaged and reengaged to permit cleaning of the parts. Evaporation of solvent from the samples can be assisted by providing a suitable electrical heater in the base plate.
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United States Patent LaFleur et al.

[ Dec. 25, 1973 TEMPLATE FOR THIN LAYER CHROMATOGRAPHY SAMPLES [75] lnventors: Bob A. LaFleur; Robert J. OBrien,

both of Rochester, NY.

[73] Assignee: Eastman Kodak Company,

Rochester, NY.

[22] Filed: Oct. 14, 1971 [21] Appl. No.: 189,112

[52] US. Cl. 118/503, 118/504 [51] Int. Cl. B05c 11/12 [58] Field of Search 118/504, 505, 406, 118/301, 503; ll7/8.5, 38; 101/126; 83/454, 459, 465; 408/241 B, 72; 51/310, 262; 269/91, 93, 92, 94, 87.2, 87.3

[56] References Cited UNITED STATES PATENTS 3,109,641 ll/l963 La Pierre 118/504 X 2,899,928 8/1959 Pataky 118/505 X 3,380,434 4/1968 Faber 118/504 X 2,704,992 3/1955 Schell 118/49 3,280,794 10/1966 Rosenberg 118/301 3,161,543 12/1964 Borders et a1. 118/503 X 2,125,457 8/1938 Merritt 117/38 X 3,685,916 8/1972 Loomis. 408/72 1,575,564 3/1926 Fleming 118/415 Primary Examiner-Morris Kaplan Att0rneyWilliam T. French et a1.

A template for holding a chromatographic sheet while permitting the application of a series of liquid samples rapidly, and on a well defined area of fixed size, comprises a base plate adapted to receive a chromatographic sheet on its surface, an applicator plate mating with the base plate and adapted to lie on top of the sheet, and means for clamping the parts together to hold the sheet in place. The applicator plate and the base plate are hinged together and provided with latches for clamping them together. To provide wells for receiving liquid samples, the applicator plate has a plurality of bores therethrough within which are pressed plastic bushings for engaging the chromatographic sheet without damaging its delicate surface. Also, two stop springs ease the movement of the applicator plate into register with the base plate so as to avoid damage to the chromatographic sheet. The base plate is provided with an abutment against which an edge of a chromatographic sheet is precisely positioned. The hinges are readily disengaged and reengaged to permit cleaning of the parts. Evaporation of solvent from the samples can be assisted by providing a suitable electrical heater in the base plate.

ABSTRACT 9 Claims, 3 Drawing Figures TEMPLATE FOR THIN LAYER CHROMATOGRAPHY SAMPLES BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel improved apparatus for rapidly applying samples to a chromatographic sheet.

2. The Prior Art The chemical analysis of many compositions has been conducted successfully by spotting the compositions on a thin sheet of paper, glass or synthetic resin which carries an adsorbent coating on a surface thereof, such as powdered cellulose, silica gel, alumina, nylon, polyethylene, etc. Reference is made to US. Pat. Nos. 3,418,152; 3,418,158; 3,492,155; 3,498,830 for more details.

After the sheet has been spotted with one sample or a series of spaced samples and dried, it is dipped into a chromatographic eluant solvent such as benzene, alcohols, chloroform, water, etc. and developed in a closed chamber such as that shown in US. Pat. No. 3,413,842. The solvent migrates along the sheet, carrying the components of the sample spots with it, with individual components travelling at different rates. The components are identified by comparison with a chromatograph of a known composition.

Usually the spots have been applied by dissolving the unknown composition in a volatile solvent such as methyl or ethyl alcohol, or acetone to form a liquid sample, and then repeatedly dabbing small quantities of the sample on the chromatographic sheet while allowing solvent to evaporate between dabs. This is a slow and expensive procedure, and also is disadvantageous because it is difficult to confine the sample to a well defined small area. I

In US. application Ser. No. 176,627 which was filed on or about Aug. 31, 1971 by AD. Baitsholts, N.E. Jackobs and I. Timrots, entitled Template For Applying Samples To A Thin Layer Chromatographic Sheet," there is disclosed a novel apparatus and method for solving the above problems of the prior art. The present invention is an improved template apparatus, which is so constructed as to prevent damage to the thin layer surface of a chromatographic sheet while assuring that a seal is maintained at that surface to confine the sample spots to a small area. Our novel apparatus is also so constructed that a chromatographic sheet can be precisely and quickly positioned for receiving samples; and that the parts can be easily and rapidly disassembled for cleaning, and just as rapidly and easily reassembled for use.

SUMMARY OF THE INVENTION As in the application mentioned above, our novel apparatus comprises a base plate adapted to receive a chromatographic sheet on its surface, an applicator plate mating with the base plate and adapted to lie on top of the sheet, and means for clamping the various parts together to hold the chromatographic sheet in place.

The applicator plate has at least one hole therein acting as a well for receiving a liquid sample solution, and advantageously a plurality of such holes such as up to 19 or more lying on a straight line so that all samples are applied to a chromatographic sheet the same distance from its edge.

Evaporation of the solvent from the sample to leave a defined dry spot of the substance to be analyzed occurs while it is confined to the well, and may be accomplished under ambient conditions. or by providing means for heating the apparatus if a greater evaporation rate is desired.

The improvements of our invention over the prior application include the hinging of the applicator plate to the base plate for pivotting movement into and out of register with the base plate, and the provision of one or more rapid acting latches on one of the plates which are movable into and out of engagement with the other of the plates for clamping a chromatographic sheet between the plates. The hinge mounting advantageously comprises two half hinges which can be moved into and out of engagement with one another to separate the plates for cleaning.

Another improvement lies in the provision of abutment means, such as properly positioned dowels and/or shoulders on the base plate, against which an edge of a chromatographic sheet is accurately positioned for receiving samples.

When moving the applicator plate into position on top of a chromatographic sheet, a seal with the surface of the chromatographic sheet at each hole or bore is assured by a bushing of resilient plastic material such as Teflon polytetrafluorethylene within each bore and protruding therefrom. The resilience of each bushing causes it to yield slightly when engaging the chromatographic sheet, and thus avoids removing surface material. Additionally, the surface is protected against damage by providing resilient stop means, such as two coil springs, which are carried by one of the plates and are adapted to engage the other plate just before the applicator plate contacts the chromatographic sheet, so as to ease or arrest its movement and prevent harmful impact against the sheet.

THE DRAWINGS FIG. 1 is a plan view showing our novel template apparatus in open position ready to receive a chromatographic sheet;

FIG. 2 is a plan view showing the applicator plate closed into operating position on top of the base plate as though a chromatographic sheet were positioned therein; and

FIG. 3 is a cross sectional view on an enlarged scale taken along the line 3-3 in FIG. 2.

THE SPECIFIC EMBODIMENT Referring to the drawings it will be seen that our novel apparatus comprises a base plate 11, and an applicator plate 13 which is hingedly mounted on the base plate by cooperating half hinges l5, 17 on one side of the base plate, and 19, 21 on a side of the applicator plate. The half hinges 19, 21 are laterally slidable on hinge pins 20 for disengagement of applicator plate 13 from base plate 11, and reengagement therewith.

Both plates 11 and 13 can be constructed of a metal such as stainless steel to resist corrosion by sample solutions. If desired, base plate 11 can be formed of two elements, the main part 11a being stainless steel, and extension 11b being formed of a lighter and less expensive material such as a plastic, for example, a phenolformaldehyde resin. The two elements can be bolted together.

Base plate 11 is provided with two protruding abutment pins 23 arranged on a line parallel to and spaced slightly from the hinged edge of the plate for contact with an edge of a rectangular chromatographic sheet which is positioned on top of the base plate for receiving samples. Instead of pins 23, a shoulder may be formed by milling or otherwise providing a concave or depressed area in the base plate within which the chromatographic sheet lies. The side edges of the chromatographic sheet are also guided and positioned properly by engagement with a pair of side shoulders 27 and 29. A slight flaring of these shoulders at their entrance ends will ease the introduction of a chromatographic sheet.

When the chromatographic sheet has been positioned on base plate 11, the applicator plate 13 is swung over on top of the sheet in position for applying samples. Just before the applicator plate reaches the sheet it encounters a pair of stop springs 31 embedded in the sides of the base plate which case the downward movement and prevent the applicator plate from damaging the thin adsorbent layer on the chromatographic sheet. I

Applicator plate 13 is provided with a plurality of holes or bores 35 therethrough which are aligned with one another, and spaced slightly apart, in position for applying samples to a series of areas of the chromatographic sheet which are evenly spaced from shoulder 23 and the coactng edge of the chromatographic sheet. Holes 35 are frusto conical in their upper portions, and merge smoothly at their lower portions into cylindrical portions.

As shown in FIG. 3, each bore 35 comprises a bushing 37 which protrudes a short distance beyond that surface of applicator plate 13 which registers with base plate 11, so as to engage the surface of the chromatographic sheet and form a tight seal therewith, thus pre' venting migration of a liquid sample outside the circular area of engagement. The protruding part of each bushing is bevelled to assure tight engagement with a sheet. The bushings 37 should be a resilient material, for example a plastic such as Teflon polytetraflumethylene, polyethylene, polypropylene, or other well known plastic materials which will resist the action of solvents employed for applying the samples to the chromatographic sheet.

In order to expedite evaporation of solvent from the samples, base plate 11 is provided with a lateral bore within which is positioned a cylindrical electrical resistance heating element 41. A rheostat can be provided for regulating the temperature so as to avoid charring or melting the chromatographic sheet.

When using the apparatus the chromatographic sheet is positioned on base plate 11 with its leading edge against abutments 23 and its side edges confined between abutments 27 and 29. Applicator plate 13 is then swung into position with all of the bushings 37 in contact with the sheet, and the latches 43, are actuated into engagement with pins 47, 49 to assure such contact. Then the full amount of each sample, dissolved in its solvent, is introduced into each sample hole 35 and heat is applied from the heater 41 to cause the solvent to evaporate and leave a well defined circular area ofdried solvent on the chromatographic sheet. Then the latches are disengaged and the plates are swung apart from one another so that the chromatographic sheet can be removed for subsequent introduction into elution apparatus in a conventional way.

With this construction there is no longer reason to apply a sample by repeatedly dabbing it onto the surface of a chromatographic sheet over a long period of time, because the full amount of a sample can be introduced at one time and the solvent allowed to evaporate therefrom in one fifth the time or less. When a series of samples are to be analyzed on the same chromatographic sheet they can all be introduced in full volume at the same time through a series of the sample holes 31 and then allowed to dry much more rapidly than was previously possible.

Rapid application of samples, as by the above described apparatus and method is of prime importance in clinical laboratories or drug detoxification centers where thousands of samples are chromatographed every week. Where it previously required 5 minutes to apply each sample, using a hot air dryer between dabs of only 2-3 microliters, it is now possible to apply each sample in less than 15 seconds.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

We claim:

1. Apparatus for applying liquid samples to a' chromatographic sheet comprising, in combination,

a base plate adapted to receive a chromatographic sheet on the surface thereof; an applicator plate hingedly mounted on said base plate for movement into and out of register with the top of said base plate, said applicator plate being adapted to lie on such a sheet and having a plurality of holes therethrough for receiving a plurality of liquid samples to spot said sheet; and

said applicator plate comprising a bushing of resilient material in each of said holes and projecting therefrom in position to engage and to form a tight seal with such a sheet.

2. Apparatus in accordance with claim 1 wherein said base plate has abutment means thereon adapted to engage an edge of such a chromatographic sheet to position such a sheet for receiving a sample.

3. Apparatus in accordance with claim 1, also comprising resilient stop means carried by one of said plates and adapted to engage the other of said plates during movement into register with one another, to arrest such movement and prevent harmful impact against such a chromatographic sheet.

4. Apparatus in accordance with claim 1 wherein said base plate and said applicator plate each has half hinge means thereon, said half hinge means being movable into and out of engagement with one another for detaching said applicator plate from said base plate at will.

5. Apparatus in accordance with claim 1 wherein said base plate has abutment means thereon adapted to engage an edge of such a chromatographic sheet to position such a sheet for receiving a sample;

said apparatus also comprising resilient stop means carried by one of said plates and adapted to engage the other of said plates during movement into register with one another, to arrest such movement and prevent harmful impact against such a chromatographic sheet.

6. Apparatus in accordance with claim 5 wherein said base plate and said applicator plate each has half hinge means thereon, said half hinge means being movable into and out of engagement with one another for detaching said applicator plate from said base plate at will.

7. Apparatus in accordance with claim 2, wherein said holes arranged in a straight line parallel to said abutment means for applying a plurality of samples to such a chromatographic sheet along a straight line parallel to such edge thereof.

8. Apparatus in accordance with claim 1, also comprising latch means on one of said plates movable into and out of engagement with the other of said plates and acting to clamp a chromatographic sheet between said pin means.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,78 ,7 Dated December 25, 1973 Bob A. LaFleur, Robert J. O'Brien It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 7, line 2, after "holes insert -.-are--.f

Claim 9, line 1, change "8" to --6--.

Signed and sealed this 30th day" ,of April 1 97b (SEAL) Attest:

EDWARD I-Z.l-LEICHJ5R,JR. c. EL TE-STEELE IL ANN AttestingOfficer Commissioner of Patents

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1575564 *Jun 16, 1924Mar 2, 1926Gordon Fleming JohnGumming device
US2125457 *Nov 22, 1935Aug 2, 1938Tanning Process CompanyArt of decorating sheet material
US2704992 *Dec 28, 1951Mar 29, 1955Erie Resistor CorpGas plating apparatus
US2899928 *Feb 10, 1956Aug 18, 1959 De pataky
US3109641 *Dec 16, 1960Nov 5, 1963La Pierre William HAdjustable temple piece holder
US3161543 *Apr 16, 1962Dec 15, 1964BordersWork handling apparatus for applying flocked designs
US3280794 *Apr 15, 1960Oct 25, 1966Int Latex CorpCoating apparatus including masking means
US3380434 *Aug 27, 1965Apr 30, 1968Deco Tools IncDecorative painting fixture
US3685916 *Mar 12, 1971Aug 22, 1972Charles M LoomisBolt hole drilling jig for elevator installation
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4004548 *Sep 15, 1975Jan 25, 1977Eastman Kodak CompanyChromatographic spotter
US4367579 *Oct 6, 1980Jan 11, 1983Emkay Manufacturing Co. Inc.Method of connecting a crystal to a crystal holder
US4980240 *Apr 20, 1989Dec 25, 1990Honeywell Inc.Surface etched shadow mask
US5139610 *Oct 31, 1990Aug 18, 1992Honeywell Inc.Method of making a surface etched shadow mask
Classifications
U.S. Classification118/503, 118/504
International ClassificationG01N30/91, G01N30/00
Cooperative ClassificationG01N30/91
European ClassificationG01N30/91