JPS5876751A - Electrophoresis apparatus - Google Patents

Abstract

PURPOSE:To enable an accurate detection of the front end of each ion component zone reaching the desired position of a migration path by hourly integration of a migration current detected. CONSTITUTION:When a composition of a leading liquid is provided to a computer 9 through a console 11, a corresponding quantity Q of electricity is read out of a memory and set internally. Then, a boundary is produced between the terminal liquid and the leading liquid in a sample injecting section 5 and a sample is injected. A computer 9 controls a d.c. high voltage power source circuit 2 so that a relatively large emigration current i1 is fed back to the computer 9 through a current detection circuit 10 for hourly integration thereof whose results, the quantity q, is compared with the value Q. When they coincide, the current i1 is switched to a relatively small emigration current i2. At this point, the rear end of the ion component zone of the leading liquid reaches a stepped section 7c and the sample emigrates through a capillary tube 7b.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophoresis apparatus, and more particularly, to an electrophoresis apparatus equipped with means capable of detecting that the front end of an ionic component zone of a sample is passing through an arbitrary position of an electrophoresis path. .

In an electrophoresis device, it is necessary to detect that the front end of the ionic component zone of the sample passes through a predetermined position of the electrophoresis path, especially when separating ionic components from the sample, or conversely, when This occurs when removing external components. Conventionally, this detection means is based on patent office literature &
76-5884911 (Journalofofohro
matography, 119 * 1976
) + As described on the SIO page, the detector that is originally included in the electrophoresis analyzer also has the function of the detection means.
It is known that a similar detector is installed at a predetermined position in the migration path separately from the original detector, as described in Japanese Patent Publication No. 1986-8AO2 (↓).

However, in the former case, the application is limited because detection can only be performed at the position where the detector is originally installed, and in the latter case, the use of the detector is limited. Since another detector must be installed in IIJIyjS, the apparatus C°1 becomes complicated.

Furthermore, since the output signal of the detector varies depending on the composition of the sample S and the mouse, it is necessary to select conditions for determining the meaning of the output signal for each sample, otherwise accurate detection will not be possible. That is J).

This invention was made in view of this situation,
An object of the present invention is to provide an electrophoresis device that solves the above-mentioned problems.

That is, the present invention detects electrophoresis current in an electrophoresis apparatus in which a sample is electrophoresed in an electrophoresis path connected between a terminal liquid electrode tank and a leading liquid electrode tank connected to both ends of a high voltage power supply circuit. An electrophoresis apparatus is provided which includes a current detection means and a current integration means for temporally integrating the detected current.

Specifically, the current detecting means can be obtained by, for example, inserting a small resistance in the connection line connecting one end of the high voltage power supply circuit and one of the electrode tanks, and the current integrating means can be obtained by interposing a small resistance in the connecting line connecting one end of the high voltage power supply circuit and one of the electrode tanks. This can be obtained by providing an integrator that integrates the voltage across both ends.

As is well known, the amount of electricity supplied during electrophoresis is directly proportional to the migration distance of one ionic component zone. Therefore, by knowing the amount of electricity, it is possible to know the electrophoretic distance. Now, if we focus on the ionic component zone of the leading liquid, the relationship between the migration path 1iIIL and the ton Qi band is as follows.
It depends only on the composition of the leading fluid. However, since the rear end of the ionic component zone of the leading liquid is nothing but the front end of the ionic component zone of the sample, the migration distance of the front end of the ionic component zone of the sample is also related to the electrophoretic distance F of the ionic component zone of the leading liquid and the amount of electricity. NiJ: You can know that. In other words, as long as the leading liquid is the same, the migration path of the ionic component zone of the sample can be determined from the air volume using the same judgment conditions, and there is no need to specify the composition of the sample or the stars. become.

The output of the current integration means is exactly l=ijl! After all, according to the "electrophoresis apparatus of the present invention," the front end of the ion component zone of the sample migrates at a maximum speed of 1/Z when the current integrating means is launched.
This means that you will be able to know what is going on. Moreover, the detection position is arbitrary, and there is no need to change the output signal discrimination condition depending on the test S].

By the way, in order to simultaneously achieve the objective 2-] of shortening analysis time and detecting with high accuracy in capillary 2 isokinetic electrophoresis ur analysis, the ion migration speed is increased by increasing the ion flow at the beginning of the analysis. A method often used is to reduce the electrophoresis current in the latter stages of the analysis to suppress the generation of Joule heat and to achieve accurate detection. What is important in this method is appropriate timing for switching the electrophoresis flow.

For this purpose, in conventional devices, separate detectors were installed at various positions along the migration path to detect the time when the sample passed through the ion component zone. Since the output signal of the instrument differs depending on the sample composition and type, there was a problem in that the conditions for determining whether the sample passed through the ionic component zone had to be appropriately selected for each sample.

In the electrophoresis apparatus W of the present invention, as described above, there is no need to change the discrimination conditions for each sample.

Therefore, if the electrophoresis apparatus of the present invention is used to switch the electrophoresis current based on the output signal of the current integration means, the electrophoresis current can be changed at an accurate timing under certain discrimination conditions, regardless of the condition of the sample. It becomes possible to switch between

Hereinafter, the present invention will be explained in detail based on an embodiment shown in the drawings, and the apparatus shown here is a capillary type isotachophoresis analyzer configured to switch the electrophoresis current as described above.

(1) is a capillary type isotachophoresis analyzer 117, with a direct current of 1
A terminal liquid tank, a glue tank (3), and a leading liquid electrode tank (4) are connected to both ends of the crystal Vlj pressure power supply circuit (2), and a trial liquid electrode tank (1) is connected between these two mai tanks (3) and (4). Injection part (5) and detection +! : +, (6) are connected by a pipe line (7) 1. The pipe line (7) between the sample injection part (5) and the detector (6) is a pipe with a large diameter. Retuffe (?
a) and a cabillary reach pipe (7b) with a small pipe diameter are connected in series via a stepped portion (7c). It is a two-tiered tube with J flavor. The output of the DC high voltage 41 - electric pongee circuit (2) is controlled by the microcomputer (9) via the ItIN circuit (8). (11) installed in the connection line between the DC high voltage electric m1ttl path (2) and the terminal liquid electrode tank (3) is a current detection circuit, and its output is ) is entered. ,
(II) is in operation.

Now, this outfit! When the analysis migration path is a two-stage tube as in (1), a large current is supplied when the ionic component zone of the sample migrates through the pretube (7a), and the ionic component zone of the sample migrates through the capillary tube. (7b)
Supplying a small m flow when electrophoresing
This is desirable in terms of shortening analysis time and performing accurate detection3.Therefore, it is important to know the time when the front end of the ion component zone of the sample reaches the stepped portion (7C), and to start swimming at that time.
1! It is preferable to switch the II current from a large current to a small current.

For this purpose, in advance, in this setup ff+;t[), we have determined the composition of the leading liquid and the rear end of the ion component zone of the leading liquid when used. Microcomputer (9)
is stored in

For analysis, the composition of the leading liquid is input into the microcomputer (9) via the operator console αυ.

Then, the microcomputer (9) reads out the corresponding quantity of electricity Q from the memory and sets it internally. Next, create an interface between the terminal liquid and the leading liquid in the sample injection part (5) using the usual procedure, inject the sample, and input a start command from the operation console (10).This command causes the microcomputer (9) to Pressure 11f of 1 current 1'I"1 via control circuit (8): Control circuit (2)
5. Control the electrophoresis and supply a relatively large electrophoresis 1 noise current 11 (t, for example, 200 to 300 μA). l1Jl
The li'lf flow 11 is fed back to the micro-1 'novi' user (9) by the current 1 detection circuit 01 step. Microphone 1] The 7I viewer (9) uses this electrophoretic current 1
1 from time to time, compare the electricity iit q obtained by the integration with the electricity quantity Q, and when they match, swim! l1II current i1 is a relatively small electrophoretic current 1
2 (7,7 and tr 211 to 100 μA). mkih (q is 1)
As described above, this is when the rear end of the ionic component zone of the leading liquid reaches the stepped portion (70), that is, when the curved end of the ionic component zone of the sample reaches the stepped portion (7c). .

Therefore, the sample is first subjected to a large electrophoresis flow of 14 I, and then to 11 J:
-:) and migrate in the pretube (7a), then a small swim! 1iJJ flow 12 capillary tube (7
b) will migrate within. Moreover, this is done accurately regardless of the composition or amount of the sample.

As can be understood from the above description, the electrophoresis apparatus of the present invention detects when the front end of the ion component zone of the sample has reached an arbitrary position in the migration path and detects the composition and amount of the sample. be able to detect accurately without any Therefore, it is extremely useful for analyzing unknown samples. In addition, since only the integrated value of the electrophoretic current is considered and the instantaneous value is not a problem, there is an advantage that accurate detection can be performed in both cases, whether the electrophoretic current is a constant current or a current that changes every moment. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the electrophoresis device fM of the present invention. (1)... Capillary isotachophoresis analyzer G, (2)...
...DC high voltage electrical circuit, (3)...Terminal liquid electrode tank, (4)...Leading molding 81! Monk, (7)...
Conduit, (8)...Control circuit, (9)...
・Microcomputer,

Claims (1)

[Claims] 1. In an electrophoresis device that electrophores a sample in a migration path connected between a terminal liquid wheel electrode tank and a leading liquid electrode tank connected to both ends of a high voltage power supply circuit, What is claimed is: 1. An electrophoresis apparatus comprising: a current detecting means for detecting current; and a current integrating means for temporally integrating the detected current.