CH658797A5 - METHOD AND DEVICE FOR THIN-LAYER CHROMATOGRAPHY. - Google Patents

Description

The present invention has for its object to provide a method for performing a thin layer chromatography, which allows faster chromatography with little equipment and with low consumption of flow agent and facilitates the quantitative evaluation.

This object is achieved according to the invention by a method which is characterized in that the superplasticizer is supplied along a supply line, the superplasticizer simultaneously spreading in two opposite directions transversely to the supply line and the supply line extending over the entire width of the sorption layer of a TLC plate , furthermore that the flow of superplasticizer is varied in time and place by interrupting the flow of superplasticizer and shifting the feed line in the transverse direction relative to the DC plate.

This also eliminates the temporal disadvantage of DC with longer superplasticizer runs, whereby this is done with minimal superplasticizer consumption. The method also offers the possibility of a simultaneous flow of flux in two opposite directions on the DC layer.

The method according to the invention is explained on the basis of the following descriptions and the drawings, and exemplary embodiments of the device for carrying out the method are shown. In the drawings:

Figure 1 is a plan view of a DC chamber for the application of the inventive method.

FIG. 2 shows a cross section through the disassembled chamber of FIG. 1;

3 a) a view and b) a cross section of the strips for the magnetically actuated flow agent supply;

4 a) a top view and b) a cross section of the strips for the mechanically operated superplasticizer;

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5 a) a cross section of the strip in the plasticizer container when the plasticizer supply is interrupted and b) when the plasticizer supply takes place.

The same elements are identified in the same way in all drawings.

1 and 2 show a DC chamber for the application of the method according to the invention with the supply of superplasticizer along a supply line. The device shown here enables the flow of the flow agent to spread simultaneously in two opposite directions. The inner height of the DC chamber can be varied in the range from 0 mm to approx. 0.5 mm using super-thin intermediate inserts. One speaks of a “sandwich” DC chamber. By adjusting a minimum DC chamber height, the gas content of the chamber can be reduced to a minimum. Therefore, there are almost no saturation problems with the gas phase.

The removable holding frame 1 for DC plates 5 is closed with a cover glass plate 2 and can be moved tightly along the entire length of the chamber base plate 6. The magnet holder 14 with the magnet 15 is removable and easily positioned by two guides. The length of the displacement of the holding frame 1 is adjustable by two scales 3 attached on both sides. The chamber is provided with a fixed foot 12 and two adjustable feet 13, as can be seen in FIG. 2, and can be adjusted horizontally by means of a spirit level. A flow medium transfer strip 11, which is pushed onto a magnetizable bar 10, is inserted into the flow medium container 9. The fluid is then injected with a syringe 7 through line 8 into the fluid container 9 in the chamber base plate 6. The samples to be analyzed can be applied in two rows to the DC layer (for example also in the middle of the DC plate). The plate 5 is finally inserted into the holding frame 1 and held there with a spring system 4. The holding frame 1 together with the DC plate 5 is placed on the base plate 6 and positioned as desired. After inserting the magnet holder 14 with the magnet 15, the iron bar 10 is raised by the magnetic force 11 and pressed onto the layer 5. That's where the development begins. After the magnetic holder 14 has been removed, the iron bar 10, together with the strip 11, falls back into the plasticizer container 9, and development is thus interrupted. After moving the plate frame 1 into another desired position and then placing the magnet holder 14 on it, a new development begins at this point. The developments with this device take place across the entire width of the sorption layer, as well as in two opposite directions across the feed line. Therefore, they run significantly faster compared to conventional devices. The parallel spread also facilitates the quantitative evaluation of developments. The plate frame 1 can also be moved several times to different locations on the sorption layer and the developments can also be carried out with different flow agents. The remaining residues of the respective flow agent in the flow agent container 9, 19 can advantageously be emptied with a syringe 7 and then vacuumed off. The vapors of the superplasticizer can be extracted in the same way. The line-shaped superplasticizer transfer also leads inevitably to a focusing effect of the separated rows of substances, which takes place in a matter of seconds after the superplasticizer supply has been shifted from one side to the other. Each development can be carried out with the same or a different flux opposite to the previous development direction. 5a and b show a mechanically operated fluid transfer with a thick strip 17 in a vertically movable fluid trough 19. The supply of superplasticizer to the DC layer 5 er-15 follows via the edge 18 of the strip 17 when the superplasticizer trough 19 is raised. In both examples described, the displaceability of the parts can be reversed. Thus, the chamber shown in FIGS. 1 and 2 can also be constructed from a fixed holding frame 1 and a displaceable base plate 2o 6. The container 19 shown in FIGS. 5a and b can be fixed and the DC plate 5 together with the frame 1 can be moved vertically.

The process with time-variable supply of superplasticizer and location-variable supply line to any point 25 of the sorption layer is called “SEQUENCE DC TECHNOLOGY”. This DC chamber according to the invention is preferably made of anodized aluminum, glass or other, e.g. made with PTFE coated material.

However, other materials can also be suitable. This 30 type of superplasticizer supply to the separating layer can also be used in electrophoresis if the superplasticizer trough 9 together with the supply line 8 is sufficiently insulated from the chamber and the chamber consists of plastic, glass or other electrically non-conductive materials. As a result, sequence DC technology can also find new uses in electrophoresis. The separation can also be easily detected during development with a UV lamp installed in the base plate 6.

The method according to the invention for carrying out a thin-layer chromatography separation brings various advantages in comparison with the conventional technology. For example, two pre-separated rows of substances can be transported from one another in a matter of seconds. The development takes place simultaneously in two opposite 45 directions, which means a double sample application, respectively. double use of the plates enables. The samples can also be applied in several rows. After the intermediate drying, another eluent can also be developed in another place. The mixtures of hydrophilic and lipophilic substances can be easily separated from one another with at least two flow agents in two opposite directions of development. The two-dimensional development of up to four samples is also easy to carry out. Furthermore, the separate diffuse rows of spots can be focused on both sides in a matter of seconds and the entire length of the DC plate layer can be used to the maximum.

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Claims (7)

658797 PATENT CLAIMS 1. A method for carrying out a thin-layer chromatography separation, characterized in that the superplasticizer is supplied along a supply line, the superplasticizer simultaneously spreading in two opposite directions transversely to the supply line and the supply line extending over the entire width of the sorption layer of a DC -Plate extends, furthermore, that the flow of superplasticizer is varied in time and location by interrupting the flow of superplasticizer and shifting the feed line in the transverse direction relative to the DC plate. 2. Device for carrying out the method according to claim 1 with a thin-layer chromatography plate (5), which is provided with a sorption layer, and a plasticizer, characterized in that the device has a base plate (6) with a displaceably arranged holding frame (1 ), in which the DC plate (5) is held, and that approximately in the center of the base plate (6) is a flow medium container (9, 19) running transversely to the longitudinal direction with an absorbent strip (11, 17) arranged therein for the flux supply. is provided, which is movable relative to the DC plate (5) in the vertical direction and can be brought into contact therewith. 3. Apparatus according to claim 2, characterized in that the fluid container (9) is fixedly arranged in the base plate (6) and that the absorbent strip (11) is pushed onto a magnetizable bar (10), with on the holding frame (1) a removable magnetic holder (14) with holding magnets (15) can be placed, by means of which the strip (11) can be moved in the vertical direction relative to the DC plate (5) and brought into contact with it. 4. The device according to claim 2, characterized in that the fluid container (19) is movably arranged in the base plate (6) and in that the absorbent strip (17) is located and protrudes with at least one edge from the fluid container, so that at one vertical displacement of the fluid container (19) to the DC plate (5) of the strips (17) can be brought into contact with the sorption layer of the DC plate (5). 5. The device according to claim 2, characterized in that in the holding frame (1) above the DC plate (5) a sealing glass cover plate (2) is attached. 6. Device according to claims 3 and 5, characterized in that the flow agent can be regulated via a feed line (8) opening into the flow agent container (9) by means of a syringe (7) which can be fastened to the base plate. 7. The device according to claim 2, characterized in that the base plate can be brought into the horizontal position by means of support feet designed in the manner of set screws. Thin-layer chromatography, DC for short, is known as the most widespread and fastest analytical separation method. After the sample has been applied to the DC layer (stationary phase), the solution is chromatographically separated with a solution (eluent, or mobile phase) by the capillary forces. The individual substances are separated from one another at different distances. As the speed of the superplasticizer becomes slower with increasing running distance, the separation of the substances that are in the vicinity of the superplasticizer front is always slower. This disadvantage generally limits the possible uses of thin-layer chromatography. In the circular technique, the flux is applied to the DC layer in a punctiform manner, in the anti-circular technique in a ring-shaped manner or in the case of the mostly used linear DC, linearly. All previous linear fluid transfers to the DC layer always take place from the edge of the plate, either by immersing the plate in the plasticizer or by adding plasticizer with a plasticizer bridge (paper etc.) (CH-PS 364 130 and PS 450 005), as well with a capillary gap (CH-PS 2 818 576). With none of these DC chambers, the supply of superplasticizer along a supply line can take place at any point on the DC layer in such a way that the development takes place simultaneously in two opposite directions and is thereby accelerated. The unevenness of the DC layer makes it difficult or impossible to feed the flux, evenly, in a line and without wick, and leads to damage to the DC layer. Only when using so-called area dosers for DC does this not damage the DC layer, but the wide contact area between the area doser and the DC layer makes it impossible to separate rows of stains that are close together. The method described in the literature (Anal. Chem. 1981, 53.714 716) uses a syringe to route the superplasticizer for rapid DC separation. However, this brings about geometric distortions of the substance stains and makes quantitative evaluation more difficult, since the superplasticizer can only be added in a punctiform manner. In addition, one syringe is required for the flow of superplasticizer for each substance stain and all syringes must be provided with a control mechanism. For a 20 cm wide DC plate, for example, over 30 syringes are required!