JPH0213959Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a micro-sample measuring device, and an object of the present invention is to provide an apparatus that can easily and quickly measure a micro-sample.

First, an embodiment of this invention will be described in detail based on the drawings. In FIG. 1, a micro sample suction device 1 has a structure similar to a commercially available micropipette, and by pressing a plunger knob 2, a built-in piston
The cylinder works so that a suction force is applied to the tip 1a, which will be described next. That is, the ion-selective FET sensor 3 is attached to the tip 1a,
In addition, a comparison electrode 4 is provided, and an opaque conical tip cover 5 made of a conductive material is attached to the tip 1.
FET
While the sensor 3 and the reference electrode 4 are covered,
A small sample measurement chamber 6 is formed inside the tip cover 5, and a liquid suction port 7 is formed at the tip of the tip cover 5.
has been established. In addition, 10 in the figure is a connector.

Therefore, if this micro sample measuring device is immersed in a test liquid and the plunger knob 2 is lowered, the suction force passing through the suction path 8 will cause a micro sample of the test liquid to be measured from the liquid suction port 7. The sample liquid flows into the small chamber 6 and comes into contact with the tip sensing section 3a of the FET sensor 3, and the measured value is displayed on the display section 9 provided on the side of the instrument 1. In this case, by keeping the piston stroke linked to the plunger knob 2 constant, the sample liquid flowing into the small sample measurement chamber 6 can be set at a fixed amount, and by keeping the liquid level constant, the tip sensing part 3a can be reliably , and can be made to be minimally touching. In this way, only a small amount of sample is required, and contamination of the FET sensor 3 can be minimized. Additionally, the chip cover 5 has a drawback in terms of mechanical strength.
In addition to mechanically and physically protecting the FET sensor 3, the opaque structure also eliminates light effects on the FET sensor 3, which is sensitive to light, and its conductive structure eliminates electrostatic damage. .

Note that the comparison electrode 4 may be integrally molded with the FET sensor 3, or they may be arranged side by side as shown in the figure.

Furthermore, if the tip cover 5 is disposable, the amount of dirt on the entire device can be kept to a minimum, and the sample liquid will not be contaminated.

Figures 2 and 3 show a case in which a needle 10 is attached to the tip of a tip cover 5, or a glass capillary (tip diameter 1 to 10 μφ) 11 is used for ultra-micro regions such as living organisms and cells, and ultra-micro samples. This shows an example in which a needle 10 and a glass capillary 1 are attached.
1 into the desired part of the target object to collect the sample.

Although not shown, if the liquid suction port 7 of the tip cover 5 is made into an elongated pipe-like structure with the same configuration as shown in FIG. 3, samples in NMR (nuclear magnetic resonance) sample tubes, oil samples in oil pans, etc. Even in places where conventional sensors are difficult to enter, such as
Measurement can be easily performed without contaminating the FET sensor 3.

Furthermore, by utilizing the fact that the tip cover 5 is a disposable type sample cell that sucks a fixed amount of sample liquid into the small sample measurement chamber 6, as shown in FIG. If the sample solution is coated with the solution, it can be mixed into the sample solution when it is aspirated, and the pretreatment step prior to measurement can be automatically and conveniently carried out in a single action of absorbing the solution. For example, applying a pH adjuster such as Tris buffer when measuring ions such as Na ⁺ , or applying an enzyme to convert the sample liquid into a substance that can be measured with an FET sensor (for example, when measuring urea, enzyme Convert the urea concentration to a pH value using urease as
(converting to _NH3 value, etc.), and calibrating the measurement system by applying chemicals for calibration solution and sucking in ion-exchanged water. Note that this type of measuring device often requires a temperature compensation element. For example, the above-mentioned FET sensor basically has a built-in temperature compensation element, but there are cases where that alone is insufficient, or where enzymes are used and the temperature factor is If the sample is large, the pipette stand can be used as a constant temperature bath, and the measuring device of the present invention can be placed in the bath to perform measurements while sampling.

FIG. 5 shows a simple flow-through measuring device, in which the sucked sample liquid is discharged from the discharge port 14 when the plunger knob 2 is pressed, and then when the knob 2 is released, the sample liquid is discharged from the discharge port 14. A new sample liquid is sucked from the liquid suction port 7. In the figure, 15 and 16 are check valves. With this, it is possible to continuously sample and measure trace amounts of samples. FIGS. 6 and 7 show an embodiment in which a diluting device is further attached to the measuring device of the present invention. In this embodiment, first the diluent knob 20 is operated to introduce the diluent into the tip cover 5, and then the knob 2 is operated to introduce the sample liquid into the tip cover 5. Then, after stirring the whole sample by shaking it lightly, the concentration of a predetermined component in the sample liquid is measured. Next, the knob 20 is operated to introduce the diluent into the tip cover 5 for cleaning. Then, when the dirt is noticeable, the tip cover 5 is replaced.

In addition, in the figure, 21 is a diluent tank, 22, 23,
24, 25 are check valves, 26, 27 are pistons, 2
8 and 29 are stoppers. Furthermore, it is also possible to dissolve pH buffering components and interfering substance masking agents in the diluent to make the measurement using the ion electrode more complete. Measurement devices such as acidity meters and salt meters are examples of devices that are equipped with dilution devices in this way.

As described above, the present invention allows measurement of a small amount of sample to be performed easily and quickly, and the chip cover prevents damage to the sensor, contamination, etc.

In the above embodiments, an FET sensor was used as the sensor, but the present invention is not limited to this, and can be applied to various sensors such as a thermometer, a general ion electrode, a dissolved oxygen electrode, a platinum electrode, an electrode for measuring conductivity, etc. can be used.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing one embodiment of this invention, Figs. 2 and 3 are application examples when used for biological purposes, etc. Fig. 2 is a sectional view of the main part, and Fig. 3 is a sectional view of the main part.
The figure is an external view, Figure 4 is a sectional view of the main part showing an application example when applying a reagent for pre-treatment, Figure 5 is a diagram showing a modified example of a simplified flow fluid, FIG. 7 is a side view and a schematic sectional view showing a measuring device with a diluting device, which is another embodiment of the present invention. 1... Trace sample suction device, 3... Sensor,
5... Chip cover, 7... Liquid suction port.

Claims (1)

[Scope of utility model registration request] A sensor for specifying the properties of the test liquid is provided at the tip of the micro sample suction device, and a tip cover having a liquid suction port and covering the sensor is detachably provided at the tip. Micro sample measuring device.