JPH0456937B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dual pipette, that is, a dual pipette capable of suctioning and holding two types of liquids independently or simultaneously, and discharging two types of liquids independently or simultaneously. In detail, the present invention relates to a dual pipette suitable for dot-feeding a sample liquid and a reference liquid to a slide-type ion activity measuring instrument.

(Prior Art) Aqueous liquid samples, such as alcoholic beverages, drinks, tap water,
In particular, an ion activity measurement device for quantitatively analyzing the specific ion activity (or concentration) contained therein by spot-supplying biological fluids (blood, urine, saliva, etc.) using potentiometry has been disclosed. No. 58-211648,
This is disclosed in Japanese Patent Application Laid-Open No. 59-30055, Japanese Patent Application No. 59-11744, etc.

In general, such an ion activity measurement device is provided with at least one pair of ion-selective electrodes having an ion-selective layer as the outermost layer that selectively responds to specific ions, and this pair of ion-selective electrodes is attached to an upper frame. and the lower support frame. A pair of liquid spotting holes are provided in the upper frame so as to correspond to one pair of the ion-selective electrode pairs, and the sample liquid spotted and supplied to one of the pair of liquid spotting holes and the other. A porous bridge (in a preferred embodiment, a strand of fibers) is usually provided on this upper frame, which achieves electrical continuity (liquid junction) with the reference liquid dispensed onto the top frame. Furthermore, in general, when there are a plurality of pairs of ion selective electrodes, a pair of porous liquid distribution members connecting these pairs of ion selective electrodes and the pair of spotting holes are provided between the upper frame and the ion spotting holes. and the selection electrode pair.

In an ion activity measuring instrument configured in this way, for example, if three pairs of ion-selective electrodes are provided, each of which responds to Na, K, and Cl, the activities of these ions are known. When a certain reference liquid is spotted on one of a pair of liquid spotting holes and a sample liquid whose ion activity is unknown is spotted on the other, both liquids penetrate into the porous liquid distribution member and correspond to each other. reach the ion-selective electrode. On the other hand,
The interfaces of both liquids come into contact (liquid junction) near the center of the porous bridge, establishing electrical continuity. As a result, a potential difference corresponding to the difference in activity of each ion between the sample solution and the reference solution is generated between the electrodes of each ion-selective electrode pair. Using a calibration curve determined in advance from the activity (the principle is based on Nernst's formula),
The activities of Na, K, and Cl ions in the sample solution can be measured simultaneously, sequentially, or at any time.

These ion activity measuring instruments can easily measure ion activity by simply spotting a small amount of the sample solution and reference solution once, so they are useful for the analysis of aqueous liquid samples, especially those collected from the human body such as blood. It is extremely useful in clinical analysis of samples.

When spotting a sample solution and a reference solution onto such an ion activity measurement device, it is preferable that both solutions be spotted at substantially the same time, so a spotting supply means suitable for the spotting operation is desired. Ta. Especially when measuring ion activity easily, as a spot supply means,
It is convenient to use a dual pipette that can aspirate and expel both the sample solution and reference solution without mixing them.

When measuring ion activity using such an ion activity measurement device, it is possible to select whether to supply and discharge (spot supply) the sample solution and reference solution independently or simultaneously. A method of spot-supplying liquids (reference liquid and sample liquid) is desirable.

Particularly when measuring ion activity using a biological body fluid as a sample liquid, it is desirable to drop and supply the body fluid collected from the biological body onto the ion activity measuring instrument as quickly as possible without exposing it to the outside air. In other words, the dual pipette is capable of directly sucking and holding a sample liquid from within an organism, etc., and supplying this sample liquid together with a separately sucked and held reference liquid to a pair of spotting holes of the ion activity measurement device simultaneously or independently. It is desirable to have a suitable structure. However, a dual pipette having such a structure has not been known to date.

(Object of the Invention) In view of the current situation, the object of the present invention is to provide a dual pipette suitable for measuring ion activity using a sliding type ion activity measuring instrument as described above. It is.

(Structure of the Invention) The double pipette of the present invention is provided with a pair of piston members whose lower ends slide up and down inside a pair of cylinders so that one or both of them can be selectively operated. The lower part of the cylinder and a pair of dripping tips are communicated via a connecting member. More preferably, the connecting member is configured such that the distance between the tips of the pair of dripping tips can be changed by external operation.

In the present invention, the term "dropping chip" refers to a hole into which an appropriate amount (usually several tens of μ) of sample solution and reference solution can be dropped for measuring ion activity using a slide-type ion activity measurement device. It means a chip with a This dripping tip (hereinafter sometimes simply referred to as a tip) preferably has a shape that can be detachably attached to the connecting member. In particular, since it is essential to apply a clean tip to each sample for sucking and holding the sample liquid, it is essential that the tip applied to the sample liquid side has a shape that can be detachably attached to the connecting member.

The means for operating the piston member may be manual or automatic, and for example, a known vertical movement mechanism using pneumatic pressure, hydraulic pressure, or electromagnetic force (plunger, electric motor, etc.) can be used.

(Effects of the Invention) The double pipette of the present invention is capable of selectively operating one or both of a pair of piston members that slide up and down within a pair of cylinders, so that the sample liquid and the reference liquid can be selectively operated. The collection and inhalation operation is extremely easy.

That is, while it is possible to simultaneously collect (inhale and hold) the reference liquid and sample liquid, it is also possible to directly collect body fluid from the organism as a sample liquid with a pipette after collecting the reference liquid.

Thereafter, when spotting and supplying the ion activity measuring instrument, if the sample liquid and the reference liquid have substantially the same viscosity, they may be spotted at the same time. On the other hand, if the viscosity of the sample liquid is high, especially in an ion activity measurement device with multiple ion-selective electrode pairs, the diffusion speed in the liquid distribution member will be slow, so only the sample liquid should be applied early. You can also leave it there.

In addition, if the distance between a pair of tips can be changed by external operation, it is possible to widen the distance between a pair of tips when collecting a liquid, making it easier to aspirate sample and reference solutions from reagent bottles, etc. Things become easier. Thereafter, at the time of spotting, the distance between the pair of tops may be narrowed to the width of the pair of liquid spotting holes before spotting.

As described above, the double pipette according to the present invention is particularly suitable for measuring ion activity using a slide-type ion activity measuring instrument, and its utility value is extremely large.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a dual pipette according to an embodiment of the present invention, and FIG. 2 is a side sectional view thereof.

The double pipette shown in these drawings has a pair of cylinders 21 and 22 at the bottom of the housing 10, and a pair of piston members 31 and 32 have their upper ends 31A and 32A protruding from the upper end of the housing 10, The lower end portions 31B and 32B are provided so as to be able to slide up and down within the pair of cylinders 21 and 22. A pair of dripping tips 51 and 52 are connected to the pair of cylinders 2 at the lower end of the housing 10 via a pair of connecting members 41 and 42.
It is detachably attached so as to communicate with 1 and 22. The pair of piston members 31, 32 are elastically supported within the housing 10 by two pairs of coil springs 61, 62; 63, 64.

Further, an inverted J-shaped (or inverted L-shaped) opening 70 is provided on the upper side surface of the housing 10, and a pin 80 protruding from the side surface of one side 32 of the piston member moves along this opening. It can be fixed to the left and right upper ends and the lower end. If the pin 80 is fixed on either the left or right side at the upper end of the opening 70, the pair of piston members 31, 3 can be fixed at the top end of the opening 70 when the liquid is dripped.
The stroke of 2 can be adjusted to either large or small. Usually, an ion activity measurement device that has multiple sets of ion-selective electrode pairs (so-called "multi-type") has a larger amount of of liquid is required, so the larger one of the strokes corresponds to the liquid volume for a multi-type device (for example, a measurement instrument that can measure three types of ion activities simultaneously), and the smaller one corresponds to the amount of liquid for a single-type device. If the amount of liquid corresponds to , it becomes possible to easily supply amounts of liquid suitable for each of these two types of ion activity measurement instruments using a single double pipette.

As shown in the side sectional view (FIG. 2), one upper end portion 3 of the pair of piston members 31 and 32
1A can be operated independently of the other upper end 32A;
When the upper end portion 31A is operated downward, the one upper end portion 31A is also operated downward. Therefore, for example, the upper end portion 32A of the piston member 32
After operating the dripping tip 52 downward and sliding its lower end 32B downward within the cylinder 22,
When the tip of the tip is immersed in the reference liquid and the upper end 32A is returned upward, the reference liquid will be sucked into the dripping tip 52. Next, if the upper end 31A of the piston member 31 is operated in the same manner to suck the sample liquid from the tip of the dripping tip 51 and hold it in the dripping tip, the reference liquid and the sample liquid can be sucked independently. becomes possible. The reference liquid and sample liquid thus independently sucked and held are simultaneously dripped in the same amount from the pair of dripping tips 51 and 52 by operating the upper end 32A of the piston member 32 downward. On the other hand, the piston member is 31A,
By pressing downward in the order of 32A, both liquids can be discharged and dripped independently and sequentially, first the sample liquid from the tip 51 and then the reference liquid from the tip 52.

A pair of cylinders 21, 2 within the housing 10
2 and the pair of piston members 31, 32 are arranged so that their center axes are parallel to each other on the same plane. By arranging the pair of cylinders and the pair of piston members in parallel in this way, when the pair of piston members is pressed down simultaneously, the upper ends 31A and 32A of the pair of piston members
This has the effect of maintaining good engagement and smoothing the movement of the piston member. Note that the piston member 31,
If the upper part of 32 that does not slide inside the cylinder is made of a flexible member, the part that slides inside the cylinder of a pair of piston members and 1
It is sufficient to arrange the pairs of cylinders so that their center lines are parallel to each other in the same plane.

FIG. 3 is a side sectional view of a dual pipette according to another embodiment of the present invention. In the double pipette shown in this drawing, a connecting member 40 provided at the lower end of the housing 10 is common to a pair of cylinders 21, 22 and a pair of dripping tip mounting parts 43, 44 (cylinder 21 and mounting part The communication part between the cylinder 22 and the mounting part 43 and the communication part between the cylinder 22 and the mounting part 44 are independent of each other. chip spacing is fixed. In the case of a double pipette with a fixed tip spacing, a connecting member 40 and a pair of cylinders 21, 2 are used.
By configuring the pipettes 2 and 2 to be detachable and using a connecting member in which the spacing between the pair of dripping tip mounting portions is different, the pipette can be used as a double pipette with different spacing between the dripping tips. If it is not necessary to make the interval between dripping tips variable, the connecting member 4 can be
By omitting the tip spacing variable mechanism and simplifying the connecting member, the dripping tip can be easily installed and removed, reducing the possibility of malfunctions such as liquid leakage, Cost can be reduced. In addition, in the double pipette shown in Fig. 3, the upper ends 31A and 32A of the piston members are recessed in the shape of a part of a sphere with a large radius as shown in the figure, so that the upper end of the piston member can be pushed down by hand. It is designed to fit comfortably in your fingers when you use it, improving the feeling of operation.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a dual pipette with variable dropping tip spacing which is one embodiment of the present invention, Fig. 2 is a side view thereof, and Fig. 3 is a dispensing tip spacing which is another embodiment of the present invention. FIG. 3 is a side sectional view of a fixed double pipette. 10... Housing, 21, 22... Cylinder, 31, 32... Piston member, 31A, 32
A...Piston member upper end, 31B, 32B...
Lower end of piston member, 40...Connecting member (fixed dropping pipette spacing type), 41, 42...Connecting member (variable dropping pipette spacing type), 43, 44...Dripping pipette attachment part, 51, 52...Dripping tip ,6
1, 62, 63, 64...Coil spring, 70...
Opening, 80...pin.

Claims (1)

[Scope of Claims] 1. A housing, a pair of cylinders formed independently of each other within the housing, and each of which has a lower end portion slidably vertically within the cylinder and protrudes to the outside of the housing. first and second piston members each having an operating portion;
a pair of dripping tip mounting portions provided at the lower end of the housing so as to communicate with each of the cylinders via a connecting member, and a locking member provided on either one of the first and second piston members. is provided, and the locking member (a) transmits this upward movement to the second piston member when the first piston member moves upward, and moves the second piston member upward together with the first piston member; (b) when the first piston member moves downward, this downward movement is not transmitted to the second piston member; and (c) when the second piston member moves downward, this downward movement is transmitted to the first piston member. (d) when the second piston member moves upward, the upward movement is not transmitted to the first piston member. A double pipette characterized by: 2. The upper end of the first piston member consists of a flat part that can be pressed down and a lower flat part following the flat part, and the upper end of the second piston member The first piston member has a downwardly facing flat part that can engage with a lower flat part of the piston member, and a flat part that can be pressed down is located above the downwardly facing flat part. 2. The double pipette according to claim 1, wherein the pipette is provided so as to form a flat part having substantially the same height as a flat part which can be lowered. 3. The double pipette according to claim 1 or 2, wherein the connecting member is configured to be detachably attached to the cylinder. 4. The dual pipette according to any one of claims 1 to 3, wherein one dripping tip is removably attached to each of the dripping tip mounting portions.