JPH0493761A - Thin-pipe electrophoretic apparatus - Google Patents

Abstract

PURPOSE:To enable introduction of a sample, replacement of an electrolytic solution in a thin pipe and washing thereof utilizing a water pressure difference, by a construction wherein a syringe pump which can make absorption and discharge is connected to an electrolytic solution tank into which the end of the thin pipe on the opposite side to a sample introduction port is inserted. CONSTITUTION:The opposite ends of a thin pipe 1 into which a very small amount of sample is introduced are inserted into electrolytic solution tanks 2 and 6 respectively and a high voltage is impressed on electrodes 4a and 4b. Thereby components in the sample move through the thin pipe at the respective moving speeds, separated and detected 5. The solution tank 6 is closed by closing a solenoid valve 13 and one end of the thin tube inserted into the solution tank 2 is transferred to a sample bottle 3. After the solenoid valve 13 is opened and the solution tank 6 is opened to the air, subsequently, an electrolytic solution is sucked at a prescribed speed by a syringe pump 11 and thereby a solution surface level is lowered by a specified amount. After a prescribed time passes, the electrolytic solution is discharged at a prescribe speed by the pump 11 and thereby the solution surface level is restored to the original level. According to this constitution, introduction of a prescribed very small amount of sample utilizing a water pressure difference is enabled. By conducting the same operation in the state wherein the end of the thin pipe is put in the solution tank 2, replacement of the electrolytic solution in the thin pipe and washing thereof are also enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a capillary electrophoresis device, and in particular to the introduction of a certain sample into a capillary and the replacement of an electrolyte within the capillary.

It also relates to cleaning inside the capillary and replacing the liquid in the electrolyte tank.

[Conventional technology]

Capillary zone electrophoresis (CZE), which uses capillary tubes, targets extremely small samples where nQ=pQ, and is currently attracting attention as an analytical means with the highest separation ability. In the future, it is expected that this method will be applied to the analysis of biological components such as proteins and peptides. However, in the development of CZE equipment, sample introduction of nρ to PΩ with good reproducibility is
This is a major technical challenge, and conventional methods are described in Analytical Chemistry 60, (1988) No. 642.
The methods discussed on page 648 can be roughly divided into the following two types.

(1) Electrophoresis method (2) Hydraulic method (or head method) In method (1), electrophoresis is generated by inserting a capillary tube and electrodes into a sample bottle and applying a high voltage between the electrodes. Sample introduction takes place. However, this method always requires a sample with a resistance of several mΩ or more, and there is also the problem that the amount of each component introduced depends on whether the charge is positive or negative and the amount of charge each component in the sample has. .

In method (2), after inserting only the thin tube into the sample bottle, the sample bottle is lifted to a certain height, and the resulting water pressure difference (
Alternatively, sample introduction is performed using a head). This method does not have the above problem (1).

Regarding the reproducibility of sample introduction, according to the above-mentioned known example, (
This method is superior to method 1).

[Problem to be solved by the invention]

In the conventional technology using the above water pressure difference, it is necessary to move the sample bottle itself up and down. Therefore, in order to introduce the sample with good reproducibility, it is necessary to keep the sample bottle in a horizontal position.
It was necessary to move the sample bottle up and down smoothly at a constant speed, which necessitated a complicated device configuration. Furthermore, when replacing the electrolyte in the capillary and cleaning the capillary, the above-mentioned water pressure method is insufficient, and it is necessary to rely on other methods such as vacuum suction using a syringe pump.

An object of the present invention is to introduce a sample using a water pressure difference, replace an electrolytic solution in a capillary, and clean the inside of a capillary with a simple device configuration.

[Means to solve the problem]

In order to achieve the above purpose, a syringe pump or peristaltic pump capable of suction and discharge is connected to the electrolyte tank into which the capillary end opposite the sample introduction port is inserted, and the liquid level of the electrolyte is adjusted. This allows for easy adjustment. As a result, the sample can be introduced using the water pressure difference without moving the sample bottle itself up and down. Furthermore, by interlocking the electrolytic valve with the electrolytic valve that makes the electrolyte tank open to the atmosphere and the closed type, the electrolyte in the capillary can be replaced, the capillary can be cleaned, and the solution in the electrolyte can be replaced. It also made it easier.

[Effect]

The pump capable of sucking and discharging can easily adjust the liquid level of the electrolyte tank connected to the pump. Furthermore, by interlocking the pump with a solenoid valve that can make the electrolyte tank open or closed, the air pressure inside the electrolyte tank can be adjusted.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In electrophoresis using a capillary, both ends of the capillary tube 1 into which a small amount of sample has been introduced are inserted into electrolyte baths 2 and 6, and a high voltage of 1 to 30 KV is applied to the electrodes 4a and 4b using a high voltage generator 7. This is done by applying an electric current. Each component in the sample moves within the capillary at its own moving speed, is separated, and detected by the detector 5. The detected signals are processed by a data processing device 8 and output as a chromatogram report.

To introduce a small amount of sample, the solenoid valve 13 is closed to make the electrolyte tank 6 a closed type, and then one end of the thin tube inserted into the electrolyte tank 2 is moved to the sample bottle. Next, solenoid valve 1
3 and open the electrolytic solution tank 6 to the atmosphere through the tube 12, and then connect it through the tube 9 and the connector 101.
The syringe pump 11 sucks the electrolyte at a constant rate to lower the liquid level by h. After a certain period of time (1) has elapsed, the syringe pump 11 discharges the electrolytic solution at a certain speed to return the liquid level to the original level. Here, if the time required to move the liquid level up and down by h at a constant speed is tT, then the sample amount Q introduced into the thin tube 1 at this time is expressed by the following equation.

Q=Ah(t+tr) A is the inner diameter (r) and length (L) of the capillary, and the viscosity of the electrolyte (η
), density (ρ), and gravitational acceleration (g). Therefore, if the suction and discharge speeds of the syringe are kept constant, by adjusting h and t, it is possible to obtain a constant sample using the water pressure difference.

On the other hand, with the solenoid valve 13 closed and the electrolytic solution tank 6 kept in a sealed state, a certain amount is suctioned with the syringe pump 11, and the sample is sucked into the thin tube while the inside of the electrolytic solution tank is in a reduced pressure state. After a certain period of time, open the solenoid valve 13 and turn off the syringe pump 1.
By restoring the liquid level to the original level in step 1, it is also possible to introduce the sample more quickly than by using the water pressure difference described above. Furthermore, if the same operation is performed with the end of the capillary tube placed in the electrolyte bath 2, it becomes possible to introduce the electrolyte into the capillary tube and to wash the interior of the capillary tube.

FIG. 2 is a more complicated device configuration diagram based on basically the same principle as FIG. 1. The electrolytic solution is sucked and discharged using, for example, a peristaltic pump 11 instead of a syringe pump. If the electrolyte is sucked and discharged with the three-way switching valves 14a and 14b as shown by the solid lines, the solenoid valve 16a is open, and the solenoid valve 16b is closed, a sample similar to that described in FIG. 1 can be obtained. introduction, electrolyte introduction into the capillary, and tubular cleaning. In addition, this device also allows replacement of the liquid in the electrolyte tank. First, the valve 14b is switched in the direction of the dotted line to suck the liquid in the electrolyte tank 6 and discharge it to the drain.

After that, the valve 14b is switched to the solid line direction, and the solenoid valve 16
A or 16b is opened, and the electrolyte tank 6 is filled with the electrolyte solution 17a or 17b using the pump 11. Similarly, the liquid in the electrolyte tank 2 can be replaced by switching the three-way valve 14a in the direction indicated by the dotted line.

If switching of the three-way switching valve and the electromagnetic valve is controlled via the pump controller 18 in conjunction with the pump, it is also possible to automate all of the above operations.

〔Effect of the invention〕

According to the present invention, the introduction of the sample into the capillary due to the water pressure difference is achieved by simply adjusting the liquid level of the electrolyte tank into which the other end of the capillary is inserted, without having to move the sample bottle up and down while fixing the sample bottle in a horizontal position. This can be done with the @ clause.

In addition, by interlocking a pump that can suck and discharge used to adjust the liquid level with a solenoid valve that opens the electrolyte tank to the atmosphere or closes it, it is possible to introduce the electrolyte into the thin tube, Replacement of the electrolyte inside the tube and cleaning of the inside of the tube can be performed at the same time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a device showing a basic embodiment of the present invention, and FIG. 2 is a block diagram of a device aimed at automating operations. 6. Electrolyte tank, 11... Syringe pump/peristaltic pump, 13. 16a, 16b-Solenoid valve, 14a. 14b・3-way switching valve, 18・・Pump control valve. Agent: Patent attorney Katsuo Kono 11 (Figure 1)

Claims (1)

[Claims] 1. Capillary electrophoresis in which a capillary is filled with an electrolyte and a high voltage is applied between the electrolyte baths into which both ends of the capillary are inserted to separate and analyze a sample introduced from one end of the tube. 1. A capillary electrophoresis device, characterized in that a pump capable of suction and discharge is connected to an electrolytic solution tank into which the end of the capillary tube on the opposite side of the sample introduction port is inserted. 2. The sample is introduced using the water pressure difference between the electrolyte tank in which the thin tube is inserted and the sample bottle by adjusting the liquid level of the electrolyte tank to which the pump is connected using the pump. The capillary electrophoresis device according to claim 1, wherein: 3. By interlocking the pump with a solenoid valve that allows the electrolyte tank to be opened to the atmosphere or closed, the electrolyte can be introduced into the tube, the electrolyte in the tube can be replaced, the tube can be cleaned, and electrolysis can be carried out. 2. The capillary electrophoresis device according to claim 1, wherein the liquid in the liquid tank can be easily exchanged.