JPS6135968Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electrophoretic analyzer, particularly a sample component separation device in a capillary electrophoretic analyzer.

In isotachophoresis analysis, if the sample ion is an anion, for example, the capillary is filled with an electrolytic solution (leading solution) containing anions with higher mobility than the sample ions, and the sample solution is poured into one end of the capillary. The end of the tube is connected to a tank filled with an electrolytic solution (terminal solution) containing anions with lower mobility than the sample ions, and a DC voltage is applied between this solution tank and the other end of the thin tube. When a current is applied to these electrolytes, the component anions of the sample solution migrate in the tube toward the anode and gradually separate due to their respective mobilities. Zones of single component ions are formed in descending order of size, and the sample components are separated by moving at a uniform speed while maintaining a clear boundary between them. The width of each zone, ie, the length in the migration direction, is proportional to the amount of ions contained in each zone.
Therefore, by measuring the width of each completely separated zone, each component ion of the sample can be quantified. The width of each zone can be measured by detecting the boundary surfaces before and after the zone. Since the method of detecting potential gradients formed by different values is superior in terms of detection sensitivity and versatility, recently, potential gradient detectors are mainly used to detect potential gradients in each zone. Detect this potential gradient value and
By knowing the time changes of the differential values, qualitative and quantitative analysis of the sample components can be performed.

Therefore, if a capillary electrophoresis analyzer designed to perform the above-mentioned isokinetic electrophoresis analysis is used, it is possible to simultaneously analyze the sample components and separate the target components therein into the zone formed by the separation. The sample can be collected by inserting the needle of a microsyringe into the sample and sucking it out. In this kind of preparative separation, the separated sample components are subjected to thin layer chromatography,
To further ensure identification by subjecting the sample to other analytical instruments such as a spectrophotometer or liquid chromatograph, or when the sample has been taken from a living body, especially a human body, and it is difficult to collect it again. Figures 1 and 2 show examples of the preparative separation device in the analyzer conventionally used for this preparative separation.
There is a device whose configuration is shown in each figure. The one shown in Figure 1 is a preparative separation block 1 made of a transparent insulating material such as methacrylic resin, with a very short branch 3 attached to a thin tube 2 near the end opposite to the end of the tube into which the sample was injected. The needle (inhalation needle) of the microsyringe 5 is inserted into the zone 4 of the target component of the sample that has been set up, and the component is sucked out.
A needle guide 7 is attached to the preparative block 1, which prevents bending during insertion and serves as a stopper for positioning the tip. Since the opening of the needle guide 7 is closed, the opening of the needle guide 7 is closed during preparative collection.
When the inserted microsyringe 5 is pushed in until the base of the needle 6 touches the upper end surface of the needle guide 7, the needle tip pierces the septum 8 and occupies a predetermined position. Reference numeral 9 denotes a platinum wire electrode forming the detection end of the potential gradient detector, which is disposed oppositely through a small hole provided in the separation block 1 so that each end surface coincides with the wall surface of the thin tube 2.
The arrow marked along the thin tube 2 indicates the direction of migration. Compared to the device shown in FIG. 1, the device shown in FIG. 2 has the electrophoresis direction reversed, and the position of the electrode 9 of the potential gradient detector is different.
The other structures are the same, and focusing on the direction of migration, the target component is introduced into the thin tube 2 from the branch 3 of the needle 6 of the microsyringe 5 behind the electrode 9, and the target component is fractionated. It's like that. By the way, in the electrophoretic analysis described above, each component of the sample is separated in order of mobility, but the separated component zones are adjacent to each other and there is no intermediate zone between them. The length varies depending on the amount of sample and the content of each component, and there are also short zones on the mm scale. It must be possible to separate only the target component without mixing the components. Now, in order to separate the target component using the conventional apparatus described above, first, look at zone 4 of the target component of the sample from its electrophoresis direction,
The front end of the needle 6 is confirmed by the detection end 9, and the gap between the detection end 9 and the insertion position of the needle tip is determined so that the front end reaches the insertion position of the needle tip of the needle 6 due to electrophoresis. Considering the electrophoresis speed, push the microsyringe 5 into the needle 6.
Set the needle tip in the specified position and select the target component zone 4.
Insert the needle tip inside. Immediately, the microsyringe 5 is operated to start sucking out the target component. While sucking out, confirm the rear end of the target component zone 4 with the detection end 9 in the same manner as described above,
It is sufficient to estimate the delay before the rear end reaches the insertion position of the needle tip, stop suction by the microsyringe 5 before the estimated delay time elapses, and pull out the needle 6 from the septum 8. In this way, it is possible to collect less than the entire amount of the target component zone due to both the time difference in confirming the front and rear boundaries of the target component zone and the electrophoresis speed, which is usually about 1 cm per minute. Therefore, only the target component can be separated without mixing other components.

In this case, it goes without saying that the target component is sucked out by the microsyringe 5 so as not to disturb the electrophoresis state within the thin tube 2 as the zone as much as possible.

In this way, conventional devices avoid mixing the target component with other components and separate only the target component, but in conventional devices, the front end of the target component zone is detected. Accurately estimate the time lag from the time to the start of preparative separation, and the time lag from the detection of the rear end of the target component zone to the end of preparative separation, and perform the preparative separation operation in accordance with the timing. must be done,
From another perspective, the preparative separation operation in conventional equipment corresponds to the case where the time constant is large and changes in open-loop control that incorporates human elements into the control system. Although the time constant is smaller than in the case shown in the figure, it has the disadvantage that it is difficult to match the timing.

This idea was made in view of the above-mentioned current situation, and the front end of the target component zone 4 is located at the detection end 9.
As soon as the tip of the needle 6 is detected by The present invention aims to provide a preparative sorting device which eliminates the drawbacks of conventional devices by stopping suction by the microsyringe 5 and immediately pulling out the needle 6 from the septum 8 upon detection. The present invention is characterized in that the detection position and the sorting position are set at the same position, the correspondence of the sorting operation with the detection signal is increased, and the time constant when viewed from the above-mentioned open loop control system is brought close to almost zero.

Hereinafter, embodiments of this invention will be described based on the drawings. FIG. 3 is an explanatory diagram showing main parts of the configuration of the embodiment. In this figure, the first
The same reference numerals are given to the parts corresponding to those in FIGS. 2 and 2, and the explanation thereof will be omitted. In the configuration of this device, as shown in the figure, in particular, there is an opening into which the needle 6 of the microsyringe 5 can be inserted so that its tip is located between the two electrodes 9 that form the detection end of the potential gradient detector. The feature is that a very short branch pipe 3 having a (preparation port) is connected to the thin tube 2, and the detection position and the collection position are at the same position. Therefore, when separating the target component 4, as described above, the front end and the rear end of the target component zone 4 are detected, and at the same time, the microsyringe 5 is inserted, sucked out, stopped sucked out, and withdrawn. Since there is no need to wait to adjust the timing as in conventional devices, it is possible to reliably and easily separate only the target component of the sample. However, since the stop of suction during fractionation is based on a detection signal, there is a possibility that subsequent components will also be sucked in, but the amount is extremely small and is not a problem.

FIG. 4 is an explanatory diagram of the configuration of the fractionating device portion without using a microsyringe. That is, instead of the main body of the microsyringe 5, the upper end of the needle 6 is connected to a capillary reach tube 10 made of tetrafluoroethylene resin, and the needle 11 is connected to the other end.
When the front end of the target component zone 4 is detected by the detection end 9, the tip of the needle 6 is immediately inserted into the thin tube 2, and then the valves 13, 14 are connected to the preparative separation container 12. Close and syringe 1
Slowly push in the piston 5 to pressurize the target component 4 through the terminal liquid, and transfer it from the needle 6 through the capillary tube 10 and needle 11 to the fractionation container 12, and collect the target component 4 in the target component zone 4. As soon as the rear end is detected by the detection end 9, the extrusion of the piston is stopped and the needle 6 is immediately pulled out from the septum 8. In this case, the movement of the target component zone 4 in the migration direction is promoted by pushing the piston of the syringe 15 in the same direction, without mixing with the adjacent zones, so that the target component 4 can be fractionated as shown in FIG. It can be done in less time than usual.

As is clear from the above explanation, in the sample component separation device of the electrophoresis analyzer according to this invention, the sample is placed at the intermediate position between the two electrodes forming the detection end of the detector for detecting the sample component zone. Since it is equipped with a component collection port and the detection position and collection position are at the same location, it is possible to improve the compatibility of the collection operation with the detection signal, so it is possible to improve the compatibility of the collection operation with the detection signal. This method completely eliminates the difficulty of operating the conventional apparatus, in which the waiting time is accurately set and the timing is adjusted accordingly, and it is possible to easily and reliably separate the target component. It goes without saying that this invention is not limited to the embodiment in which a potential gradient detector is used as a detector for the component zone.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams showing the main parts of the configuration of a conventional sample component separation device in an electrophoretic analyzer, and FIG. 3 is an explanatory diagram of the main parts of the configuration of the embodiment according to this invention. FIG. 4 is an explanatory diagram of the configuration of the fractionating device portion without using a microsyringe. 2... Thin tube, 3... Branch part (preparation port), 4...
Target component zone of the sample, 5...Microsyringe, 6...Needle, 9...Detection end (a pair of electrodes).

Claims (1)

[Scope of utility model registration request] A capillary electrophoresis analyzer has a pair of detection electrodes installed in the capillary tube, and uses these electrodes to detect electrophoretically separated components and generate zone boundary signals for component separation. 1. An apparatus for separating sample components in an electrophoretic analyzer, characterized in that an inlet is provided at an intermediate position between the opposed detection electrodes.