FI103639B - Chromatography column end plate - Google Patents

Description

! 103639

FIELD OF THE CHROMATOGRAPHIC COLUMN TECHNICAL FIELD

The invention relates to the field of supercritical chromatography. In particular, the invention relates to the end structure of supercritical eluent chromato graphs having an effect on the distribution of substances at the column feed end and separation of fractions.

10 TECHNICAL BACKGROUND

Chromatography separates the chemical compounds from one another by introducing a mixture of them into the head of a column of solid, fine fill material and by passing or pumping from said head through the column a suitable solvent or solvent, i.e. an eluent. Some compounds bind strongly to the filler material; others elute directly through.

By varying the filler material and eluents, a combination is often found where the desired substance moves through the co-20 column at a rate that differs from that of the other substances in the mixture to the extent that the desired substance is collected in its own fraction.

Especially for a preparative-scale chromatographic age, it is essential for the resolution to be ... introduced to the top of the column as concentrated as possible. • · · * m · · • (cross-sectional area). As the different components move through the column at different speeds, the material zones remain narrow and their fronts flat. Correspondingly, at the end of the column, where the cross-sectional area of the flow path decreases • · vigorously and the eluent is discharged into the outlet, the material 2 103639 must be collected uniformly throughout the column to avoid re-mixing and fractions.

Chromatography on supercritical eluents is a rapidly developing technology. Due to the flow properties of the supercritical fluids, the viscosity is in the order of gases, the pressure drop across the filler in the supercritical column is very small compared to the liquid chromatography column. Therefore, in the prior art column, the mixture fed to its upstream end is very sensitive to the filler along the path of least resistance, and even small differences in flow resistance cause the material zone to spread.

When a mixture of substances is fed to the prior art column, there is thus a risk that the mixture of substances will not be distributed as a uniform disk at the top of the column. If there are points in the filler layer where the flow resistance is lower than in the environment, this will cause differences in the flow rate of the eluent and dispersion of the material front.

· 20

DESCRIPTION OF THE INVENTION

• · · · «

General description «

To overcome the problems described above, a supercritical eluent chromatographic column end plate structure according to claim 25, which provides a uniform flow resistance over the entire main column of the column, has now been invented. «· · For type cross section. Thus, the fed mixture saavut «« · ·; uniform distribution and uniform flow of eluent. Correspondingly, the flow resistance of the column outlet end is obtained uniformly over the entire surface, whereby the filler material through the column. · The material front arriving at the end of * * flows smoothly out of the size 3 103639 lons, for example, no material remains at the edges, which elutes more slowly and causes so-called. tailing.

s Detailed Description

In the following, "axial direction" refers to the longitudinal axis of the column, i.e. the main direction of travel of the eluent in the filler layer. "Radius Direction" means the radial direction of a cylindrical column.

10

Figures 1-4 show the inlet side of the column structure of an end plate according to the invention. Suitable materials are materials which meet the requirements of the media used and the pressure conditions, eg a suitable alloy. Acid-resistant steel is suitable for many ring applications.

Figure 1 shows the first layer of the endplate advancing in the direction of travel of the eluent and the following Figures 2-4, respectively, up to the known filler plate bounded by the filler.

The bottom has axial 1 * «· openings 1 with one-way valves through which the eluent can flow into evenly spaced radial passages 2. In addition, there is an axial opening 3 in the center, which can be known through appropriate piping and valve systems. for example, a feed mixture to be separated.

• · · • · · · ·

The space formed by the central aperture and the six radial channels • · · '· is connected via the apertures 4 to the next level channel channel. This consists of main radial channels 5 and · ... · their hexagonally located branch channels 6.

In turn, this branching duct system axially leads to a plurality of small openings 7. These openings and their pitch and diameters are dimensioned such that the pressure loss over the layer they define is significant compared to the pressure loss caused by the column filler layer. Preferably, the apertures 7 have a diameter of 0.2-0.4 mm and a spacing of about 5% of the column diameter. The apertures 7 may also consist of individually manufactured nozzle pieces mounted on the end plate body.

After the axial orifice layer shown in Figure 4, there is a known type, for example, a metal filter plate, "frit", which may have a porous density when advancing in the direction of the filler. The filter plate forms a boundary to the filler layer and is impermeable to the filler.

When the batch of material to be separated is fed, for example, through the central opening 3, it is distributed in the channel of the end plate mainly based on the flow resistance caused by the openings 7. When the apertures 7 are suitably dimensioned for the conditions, the material, when passing through the filter plate, forms a flat disc when the eluent is next pumped onto the column. through openings 1 or 3. Thus, the mixture has ·· the conditions to separate into well-defined zones as it passes through the filler layer.

When such a zone reaches the column discharge end, the solution first passes through a filter plate which is impermeable to the filler. On the other side of the filter plate, there is an orifice layer according to Fig. 4, followed by layers corresponding to Figs. 3, 2 and 1 in the downstream direction. Thus, the flow resistance of '•••' 3ο is the column. even at the outlet end is leveled so that the material zone is discharged in the column in a small volume of solution.

Claims (2)

5, 103639 A chromatographic column end plate for use in the chromatography of a supercritical eluent, characterized in that it comprises a layer having axial openings (7) with diameters selected from about 0.2 to about 0.4 mm and having a spacing of about 5% of the column. the diameter; and, on the other side of said layer, channels comprising layers for distributing or collecting eluent. 10 End plate according to Claim 1, characterized in that the openings (7) are formed by separate nozzle pieces attached to the end plate body. is a PATENTKRAV 1. An antifouling chromatographic column for an eluent, a chromatographic column with an eluent, a turn-off of a precipitate of an axial blade (7), with a diameter of 2o roll, with an interval of about 0.2 to about 0.4 mm; - stage med om avständ om ca 5% av kolonnens diameter; samt ·· att pä en sida om nd skikt finns skikt vilka omfattar MM Ψ ·; **: kanaler för fördelning eller uppsamling av eluent. • · · • · · • 1 1 ··· ', 1 1 25 2. The patented patent krav 1, the packing tongue därav att öppningarna (7) and the form of the separatum munstycken fästa i. • · • · ♦ V V V «·« M M M * · f I «I I