JPS635701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophoretic analyzer, and in particular is intended to enable analysis at constant voltage.

In capillary electrophoresis analysis, constant current is generally used to detect the target zone and perform qualitative and quantitative analysis, and constant voltage is used only in the transient stages leading up to detection. It is commonly used. This may be due to the following reasons in addition to habit.

That is, with a constant voltage, the migration speed changes over time, so direct quantification cannot be performed using a chart placed on a recording paper that moves at a constant speed.

This is because the passing speed changes while detecting the same zone and when the composition of the sample is different.
Since the resistance of the load changes, even if the voltage is constant,
This is due to the difference in the way the current changes.

The present invention has been developed in view of these circumstances, and its specific configuration includes a leading electrode tank, a terminal electrode tank, an electrophoresis tube in which a sample introduction part and a detector are installed, a voltage power supply circuit, and a power supply circuit from the detector. The voltage power supply circuit includes a detection signal calculation section and a recording section that displays the calculation data on a recording paper, and the voltage power supply circuit also includes a migration current measurement mechanism, and the calculation section or recording section records the migration current signal J from this measurement mechanism in advance. An electrophoresis analyzer comprising a control circuit that controls the paper feed speed of recording paper in proportion to the ratio J/ _JB to a set reference signal _JB , and the control circuit controls the ratio JB/ _JB of both signals. This is an electrophoresis analyzer that also controls the sensitivity of the signal axis of the recording paper in proportion to J.

That is, the present invention extracts a migration current signal,
Based on the signal, the feeding speed of the recording paper and the sensitivity of the feeding speed and the signal axis of the recording paper are each corrected and controlled to treat quantitative analysis data at constant voltage in the same way as when using constant current. This is to make it possible to do this.

The present invention will be described below based on embodiments shown in the figures. Note that the present invention is not limited thereby.

In FIG. 1, the capillary isotachophoresis analyzer S is equipped with a terminal electrode tank 2, a leading electrode tank 3, a high voltage power supply circuit 1 for both electrodes, a sample introduction section 5, and a potential gradient detector 6. An electrophoresis tube 4 that connects both electrode tanks, a calculation section 8 for calculating the detection signal from the detector, and a recording section 9 for displaying the calculation data on recording paper.
The power supply circuit 1 is further provided with a migration current measuring mechanism 7.

The calculation unit 8 calculates the electrophoresis current signal J(t) from the electrophoresis current measurement mechanism 7 and a preset reference signal.
The detection signal R(t) is proportional to the ratio J _B /J(t) to J _B
A control circuit is provided to correct R'(t).

On the other hand, the recording section 9 performs control to correct the paper feed speed V _p of the recording paper to V'(t) in proportion to the ratio J(t)/J _B between the electrophoretic current signal J(t) and the reference signal J _B. It has a circuit.

In this way, even if electrophoresis is performed at a constant voltage and the electrophoresis current fluctuates, and the potential gradient detector 6 outputs a qualitative index proportional to the fluctuating current, the paper feeding speed of the recording paper and the detection signal are Since it is corrected as described above in response to the change, the zone length on the chart can be measured and quantified in the same way as when using constant current, and it also has the advantage of shortening analysis time that cannot be obtained with constant current. is obtained.

In other words, excessive changes may occur depending on the combination of the leading liquid and the terminal liquid, and the nature and amount of the sample (particularly depending on the type and amount of counter ions each has), so general discussion cannot be made. However, in many cases, load resistance tends to increase as migration progresses. In other words, at constant current, the voltage tends to decrease. On the other hand, in order to minimize the analysis time, it is necessary to increase the electrophoresis speed, so it is necessary to apply the maximum current that can be applied at that point in time.

On the other hand, during actual electrophoresis, there are several restrictive conditions. For example, there is an upper limit for the voltage V to be applied to both ends, an upper limit for the current J to be passed, and an upper limit for J×ΔV at which the generation of bubbles does not interfere with the analysis. Therefore, if the current value is a limiting factor in the analysis system, it is appropriate to perform constant current analysis using that current value. In addition, if voltage is a limiting factor, if you perform constant voltage analysis using that voltage as described above, you will be able to analyze with the maximum current that can be passed at all times, which will shorten the analysis time. .

By the way, unlike the case of a potential gradient detector where the qualitative index is proportional to the electrophoresis current as in the above example, in the case of an ultraviolet detector, a conductivity detector, etc., the qualitative index is not affected by the electrophoresis current. As for the control circuit, only one for correcting and controlling the paper feeding speed of the recording paper is sufficient.

Of course, each of the above control circuits is memorized once,
Each signal can then be supplied when the recording paper is activated. For example, in addition to writing a chart in real time as described above, there is also a function that stores the signals R(t) and Q(t)=∫ ^t _p j(t) dt at each time t in correspondence. Later, Q(t) is plotted on the horizontal axis, and the signal magnitude R(t) (in cases like the example, J _B /j
There is also a way to write R'(t)) corrected by R'(t)) on an XY recorder, etc. as the vertical axis.

Furthermore, unlike the present invention, in a data processing device that has a function of detecting and identifying the edge of a zone, when the time of detecting the leading edge of the zone is t ₁ and the time of detecting the trailing edge of the zone is t ₂ , Q=∫ ^t2 _t1 By providing the arithmetic function j(t)dt, quantitative analysis can be performed using that value.

[Brief explanation of the drawing]

FIG. 1 is a functional explanatory diagram showing an embodiment of an electrophoretic analyzer according to the present invention. DESCRIPTION OF SYMBOLS 1... High voltage power supply circuit, 2... Terminal electrode tank, 3... Leading electrode tank, 4... Electrophoresis tube, 5... Sample introduction part, 6... Potential gradient detector,
7...Migration current measurement mechanism, 8...Calculation unit, 9...
Recording section, S... Capillary type isotachophoresis analyzer.

Claims (1)

[Claims] 1. A leading electrode tank, a terminal electrode tank, an electrophoresis tube in which a sample introduction part and a detector are installed,
The voltage power supply circuit includes a voltage power supply circuit, a calculation unit for the detection signal from the detector, and a recording unit for displaying the calculation data on recording paper.The voltage power supply circuit also includes a migration current measuring mechanism, and the calculation unit or the recording unit An electrophoresis analyzer comprising a control circuit that controls the paper feeding speed of recording paper in proportion to the ratio J/J _B of the electrophoretic current signal J from the mechanism and a preset reference signal J _B. 2. The electrophoretic analysis device according to claim 1, wherein the detector is an ultraviolet detector or a conductivity detector. 3. A leading electrode tank, a terminal electrode tank, an electrophoresis tube equipped with a sample introduction part and a detector,
The voltage power supply circuit includes a voltage power supply circuit, a calculation unit for the detection signal from the detector, and a recording unit for displaying the calculation data on recording paper.The voltage power supply circuit also includes a migration current measuring mechanism, and the calculation unit or the recording unit The paper feeding speed of the recording paper is controlled in proportion to the ratio J/ _JB of the electrophoretic current signal J from the mechanism and the preset reference signal _JB , and recording is carried out in proportion to the ratio _JB /J of both signals. An electrophoresis analyzer equipped with a control circuit that controls the sensitivity of the paper signal axis. 4. The electrophoretic analysis device according to claim 3, wherein the detector is a potential gradient detector.