CS251271B1 - Device for sample introduction into separation column - Google Patents

Abstract

The essence of the device is that of the entrance a separation column is connected from a dispensing column provided with an inlet the first electrode and the output of the second electrode, while detector separation column is provided with a third electrode, a conductor connected with a second power supply while the first power supply is connected to the first and a second electrode that is still connected with a second power supply. The solution is especially designed for capillary electrophoresis.

Description

The invention relates to a device for introducing a sample into a separation column, for example for capillary electrophoresis.

An ideal requirement for the introduction of a sample for capillary electrophoresis is the narrowest zone sharply bounded by the base electrolyte and concentrated to the base electrolyte and the concentration of the components sufficiently low to limit the electromigration dispersion.

So far, the electrophoresis sample is introduced into the separation chamber by means of a microsyringe via a septum, or through a dosing cock, hydrodynamic flow, or isotachophoretic migration. The disadvantage of these hitherto used methods is not negligible.

Microsyringe cannot inject sufficiently small amounts of sample that at the same time does not form a sharply delimited zone, but cannot reduce the large sample volume even when using miniature taps. Dosing of the sample by hydrodynamic flow is accompanied by difficult handling, the zones are deformed by the parabolic flow profile and the metering of the dosed amount is difficult.

While using electroendoosmosis to create a hydrodynamic flow, handling is simplified, but the disadvantage of measuring small amounts remains. Another disadvantage is that the amount of sample component introduced is dependent on its mobility. By isotachophoretic migration small amounts can be dosed in the form of sharply delimited zones, but their concentration is generally not selectable.

These drawbacks are overcome by the device for introducing the sample into the separation column, which is based on the connection of the separation column with a branch line from the metering column whose inlet is provided with a first electrode and the outlet with a second electrode. connected to the second power supply, while the first power supply is connected to the first and second electrodes, which is still connected to the second power supply.

The main advantage of the described apparatus is that the sample is introduced into the separation column in a short zone, with all components of the sample being represented in proportions in the original sample, the size of the loaded sample containing several nl being selectable and reproducible. The device according to the invention can be easily automated.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in greater detail in the accompanying drawing, in which there is a block diagram of an apparatus.

The block diagram shows the arrangement of the device, which consists of a dosing column 4 consisting of a capillary provided at the inlet of the dosing tap 2 ^{and in the} center with a branch 10 leading to the separation column 2 of the detector 7.

The first electrode 2 located at the inlet of the metering column 6 is connected to the first power supply 8 by a conductor. The second electrode 2 at the outlet of the metering column 4 is connected via a conductor to the first power supply 2 ^and second to the second power supply 2 '. electrode 3 at the outlet of separation column 6. ·

I ^J efore dosing is dosing a separation column 2 ^and 2 is filled with the background electrolyte. The dosing sample is fed to the inlet of the dosing column 2 through the dosing tap 5. · closing the current circuits between the three electrodes 2 '2' 2 ^{from the} power supplies 8 and 2, the ionic components of the dosing sample are carried by the current flowing towards the branch 22 ' branches to the stream ^{at the} output of the metering column 2 ^{and to the} stream ij flowing through the separation column 2 ·

The dosed sample is divided into two parts by the action of currents i 1 and i 1, in which the proportions of all ionic components of the same sign as in the sample are retained. An excess of sample is discharged by the exit of the metering column 4 under the effect of a current. The separation column 2 is then input by means of the current i to the proportion of the sample to the detector 7, which is proportional to the ratio of the branched to the total current.

The sample prior to dosing should be diluted in the base electrolyte to a concentration such that the separation is not disturbed by the electro-migration dispersion. If the electric current from the second power supply jb passing through the third electrode 3 is chosen 10 times less than the current passing from the first power supply 8 through the dosing column 6 between the first and second electrodes 1 and 2, then it will pass between the first and second electrodes 1 and 2 nine tenths of the current.

The passing currents cause the ionic components of the dispensed sample to move. Then one tenth of the sample will go to the separation column č and nine tenths of the sample will go to the electrode 2. To pass the entire dosed sample through the metering capillary, the current between the first and second electrodes 1 and 2 can be interrupted and separated. detector Ί_, *

The device is intended, for example, for capillary electrophoresis.

Claims (1)

Device for introducing a sample into a separation column, characterized in that a branch (10) is connected to the inlet of the separation column (6) from the metering column (4), whose inlet is provided with a first electrode (1) and outlet with a second electrode (2) the detector column (6) is equipped with a third electrode (3), a conductor connected to the second power supply (9), while the first power supply (8) is connected to the first electrode (1) and the second electrode (2), which is still connected to the second power supply (9).