JPS6122247A - Manufacture of ion activity measuring instrument and fusion head used therein - Google Patents

Abstract

PURPOSE:To facilitate the fixing of a porous bridge to an upper support frame by making it possible to easily and certainly fusing the porous bridge onto the upper support frame, by forming a projection onto the upper support frame of an ion activity measuring instrument and fixing the porous bridge by said projection. CONSTITUTION:A fusion head 100 comprises a body 1 having two leading end parts 2 contacted with a thermoplastic material and depression parts 3 for forming projections to the thermoplastic material are provided to the leading end parts 2 and fusion energy is supplied to the leading end parts 2 from a screw 4. A porous bridge 50 is arranged so as to interpose a spot fusion bonding hole 41 for the spot fusion bonding of a reference solution of which the ion activity is known and the spot fusion bonding hole 42 for the spot fusion bonding of a specimen of which the ion activity is unknown. The leading end parts 2 of the fusion head 100 connected to a fusion energy source are contacted with both end parts of the porous bridge 50 and a support frame 40 and projections are formed to the support frame 40 and, at the same time, both end parts of the porous bridge 50 are fused and fixed to said projections.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to the activity of specific ions in aqueous liquid samples, e.g., alcoholic beverages, drinks, water passages, and especially biological body fluids (blood, urine, saliva, etc.). The present invention relates to a method for manufacturing an ion activity measuring instrument for quantitatively analyzing ion activity (or concentration) by potentiometry, and a fusion head used in this method.

(Prior art) Slide-type ion activity measurement instruments capable of spotting a liquid sample and measuring the activity of specific ions contained therein are disclosed in JP-A-58-211648@ and JP-A-59. -3
It is disclosed in No. 0055 and the like.

In general, these ion activity measuring instruments are provided with at least one pair of ion-selective electrodes, the outermost layer of which is an ion-selective layer that selectively responds to specific ions, and the pair of ion-selective electrodes consists of two upper and lower layers. The upper support frame includes a spotting hole pair each consisting of one hole penetrating each electrode of the ion-selective electrode pair, and a spotting solution each time the spotting solution is supplied to one of the spotting hole pair. Electrical continuity with the reference liquid dotted onto the other side (
A porous bridge (twisted threads of fibers) is provided to achieve a liquid junction. In particular, an ion activity measuring instrument having a twisted thread bridge is an extremely practical ion activity measuring instrument because it can be applied not only to serum and plasma but also to whole blood as a sample.

This type of ion activity measuring device has excellent operability,
This was a breakthrough in ion activity measurement. However, until now, the porous bridge has been adhered to the upper support frame via a double-sided adhesive tape, etc., so the adhesive such as the double-sided adhesive tape seeps into the porous bridge, impeding the diffusion of the sample solution or reference solution. If it takes a long time to form a liquid junction or becomes impossible to measure, or if the adhesive strength is significantly weakened, the porous bridge may separate from the upper support frame during handling.

In order to eliminate these drawbacks, the present applicant has made the upper support frame made of a thermoplastic material, and provided that the upper support frame is made of a thermoplastic material, and the above-mentioned dots are formed at positions (fused portions) facing outwardly with the pair of dot holes in the upper support frame sandwiched between them. We previously applied for a patent for an ion activity measuring device in which both ends of a porous bridge were fixed (fused) onto the upper support frame by softening or melting this thermoplastic material (June 7, 1981, Hinode 1117). ilellj[59-
11'l'+'H).

In this ion activity measurement device, the porous bridge that connects the reference liquid and sample liquid is fixed to the upper support frame -F without contacting the adhesive, so that the adhesive does not contact the reference liquid or the sample liquid. There is no contamination, the liquid junction is reliably formed in a very short time, thus allowing for highly accurate ionic activity measurements, and the porous bridge is more secure than with traditional adhesives. It is also easy to handle.

However, in this ion activity measuring instrument, in order to securely fix the porous bridge on the upper support frame, a protrusion must be provided in advance on the porous bridge fused portion of the upper support frame, or It is desirable to supply small pieces or rods of thermoplastic material from the outside and fix the porous bridge by softening or melting them, and in such a case, although easy to manufacture, it is difficult.

(Object of the Invention) In view of the problems of the prior art described above, the object of the present invention is to provide a method for manufacturing an ion activity measuring instrument that can easily and reliably fuse a porous bridge onto an upper support frame. It is in.

(Structure of the Invention) The method for manufacturing an ion activity measuring instrument according to the present invention includes disposing both ends of the porous bridge in a fused portion on the thermoplastic upper support frame, and having a tip portion provided with a recessed portion. A fusing head is connected to a fusing energy source, the recessed portion is brought into contact with the welded portion and both ends of the porous bridge, and a convex protrusion is formed in the welded portion. It is characterized in that both ends of the porous bridge are fixed.

Note that in this specification, fusion refers to softening and bonding of thermoplastic materials.
This means that both ends of the porous bridge are fixed to the upper support frame with melting. In addition, fixation here refers to fixation by combining both ends of the porous bridge and the upper support frame into one, fixing the former to the latter while they are in contact, and fixing the ends of the porous bridge to the upper support frame. It means that the part is surrounded by a part of the upper support frame and the former is fixed to the latter.

In the method of the present invention, the welding energy source to which the welding head is connected υ′ may be any energy source as long as it plasticizes the thermoplastic material that the welding head comes into contact with, including a heat source or Ultrasonic heating sources are preferred.

In the present invention, the thermoplastic material forming the upper support frame is practically activated with respect to the sample liquid and the reference liquid, and fixes the porous bridge by softening or melting (hereinafter, fixing by softening or melting is referred to as fusion). Any suitable material may be used, for example thermoplastic polymer materials such as polystyrene, polyethylene, polyvinyl chloride, polyethylene terephthalate, etc. can be used.

The fusing head used in the method of the present invention is characterized in that the tip that contacts the thermoplastic material is provided with a concave portion that causes the plasticized thermoplastic material to form a convex projection. It is something.

(Embodiment) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of a fusion head used in the method for manufacturing an ion activity measuring instrument of the present invention, and FIG. 2 is a vertical sectional view thereof.

The welding head shown in these figures consists of a body 1 with two tips 2 which are brought into contact with the thermoplastic material, the tips 2 being provided with a recess 3, and the body 1 being fused by means of screws 4, for example. connected to an energy source. body 1
The means for connecting the body 1 to the fusion energy source is not limited to fixing with the screws shown in the figure, but any connecting means that allows the body 1 and the energy source to be removably and securely fixed may be used, such as a bayonet etc. You can also do it.

The body 1 can be made from a variety of materials depending on the thermoplastic material to be fused and the fusion energy source to be connected. For example, if the welding energy source is a heat source, it can be manufactured from brass, or from titanium, etc., by a known process such as casting, if the welding energy source is an ultrasonic source. When the welding energy source is ultrasound, an integrated welding head with as few or no joints as possible is preferred.

The surface of the tip portion 2 in contact with the thermoplastic material is approximately circular;
In this plane, the recessed portion 3 forms a circle having a radius smaller than the circle from the center of the circle. The vertical cross section of the recessed portion 3 in this embodiment is approximately rectangular as shown in FIG.

Figure 3A, Figure 3B, Figure 3C, Figure 3D, and Figure 3.
FIG. E is a partially enlarged vertical sectional view showing a recessed portion in a partially modified example of the above embodiment.

The vertical cross section of the concave portion 3A shown in FIG. 3A is trapezoidal, 8313
The vertical cross section of the recessed portion 3B shown in the figure is a semicircle, and the vertical cross section of the recessed portion 3C shown in FIG. 3C is an isosceles triangle. Although the concave portion can have various shapes as described above, it is preferable that the angle α of the isosceles of the concave portion 3C shown in FIG. 3C be approximately 120° or more. This is preferable in terms of avoiding the formation of convex protrusions. In the recesses shown in Figures 3D and 3E, a small recess is formed near the top of the large recess. The thread bridge is more securely fixed because the protrusions surrounding the thread bridge surround the thread bridge.

The dimensions and shapes of the tip portion 2 and the concave portion 3 are not limited to the above-described embodiments, and may be of any size as long as an appropriate convex projection is formed in the thermoplastic material to be fused.

FIG. 4 is a perspective exploded view showing an example of an ion activity measuring device manufactured by the method of the present invention, and FIG. 5 is a perspective view showing an embodiment of the method of the present invention during its manufacture. FIG. 6 is a perspective view of the assembly after assembly, and FIG. 7 is a partially enlarged vertical sectional view thereof.

The ion activity measuring instrument shown in these drawings is the lower support frame 1.
0, an ion-selective electrode pair 20 consisting of the same specific ion-selective electrodes 21 and 22 electrically insulated by a scratch groove or a cut groove, a water-impermeable member having adhesive layers on both sides provided with through holes 31 and 32 ( layer 30, which also serves to prevent electrical short circuits due to liquid leakage from around the spotting holes;
It consists of an upper support frame 40 provided with spotting holes 41 and 42, and a porous bridge (preferred specific example: twisted thread bridge made of polyethylene terephthalate fiber) 50.

The above-mentioned components except the porous bridge 50 can be assembled by joining and fixing the lower support frame 10 and the upper support frame 40 (by heat fusion, etc.) so that their edges match.

As shown in FIG. 5, when fixing the porous bridge 50 on the upper support frame 40, its both ends are placed so as to face each other across the spotting holes 41 and 42, and are connected to a welding energy source. The tip 2 of the connected fusion head is brought into contact with both ends and a part of the upper support frame 40 where it is located, forming convex protrusions 48 and 49 as shown in FIG. The two ends are fused and fixed by the shaped protrusions 48 and 49. It should be noted that both ends of the porous bridge are located at positions offset from the straight line connecting the center points of the spotting holes 41 and 42, so that the porous bridge is located near the periphery of both spotting holes, and when the liquid is spotted and supplied. The liquid is less likely to be repelled by the porous bridge, ensuring liquid spotting, and there is no risk of damaging the porous bridge at the tip of a liquid spotting supply device such as a micropipette when dispensing liquid. .

In the embodiment shown in FIG. 5, the porous bridge 50 is secured to the upper support frame 40-F after assembly of the other components, but after the porous bridge 50 is secured onto the upper support frame 40, the It may be combined with other constituent elements.

In addition, when manufacturing multiple ion activity measurement devices in a continuous process, a continuous thread-like porous bridge material is placed at each end of the porous bridge for each ion activity measurement device. The porous bridges may be fused and secured onto the upper support frame of the device and then cut to form the porous bridges.

FIG. 7 is a partially enlarged vertical sectional view showing the positional relationship between the convex projection 48 formed on the upper support frame 40 and the porous bridge 50 in the vicinity of the spotting hole 41.

In the embodiment shown in this figure, the ends of the porous bridges 50 pass through the convex protrusions 48. porous bridge 5
Although such an embodiment is preferred in order to securely fix the 0 on the upper support frame 40, the porous bridge may also be fixed while resting on the convex projection 48. In particular, when the compatibility between the porous bridge material and the thermoplastic material forming the upper support frame 40 is low, the latter form is often adopted.

Hereinafter, the operation of the ion activity measuring instrument shown in these drawings will be explained.

When a reference liquid in which the activity (or concentration) of a specific ion is known is spotted in the spotting hole 41 and a sample liquid in which the activity of the ion is unknown is spotted in the spotting hole 42, the reference liquid becomes water. The sample liquid passes through the through hole 31 in the impermeable member 30 and reaches one ion selective electrode 21 of the ion selective electrode pair 20 that generates a potential corresponding to the activity of the ion. and reaches the other ion selection electrode 22. On the other hand, the interfaces of both liquids come into contact (liquid junction) near the center of the porous bridge 50, and electrical continuity is established. As a result, a potential difference corresponding to the difference in ion activity between the sample liquid and the reference liquid is generated between the ion selection electrodes 21 and 22.
By measuring this potential difference, the ion activity in the sample solution can be calculated from the measured value and a calibration curve (based on the Nernst equation) determined in advance from the ion activity (1) of the reference solution.

Note that the ion activity measuring device manufactured by the method of the present invention is not limited to the shape described above,
For example, one that has multiple pairs of ion-selective electrodes (described in Japanese Patent Application No. 11744/1984), and one that has multiple pairs of ion-selective electrodes and the same number of porous bridges (twisted bridges) as the number of pairs of ion-selective electrodes (as described in Japanese Patent Application No. 59-11744), Gansho 59-11"l1.l-2
Needless to say, this includes the following:

(Effect of the invention) According to the method for manufacturing an ion activity measuring instrument according to the present invention,
By bringing a welding head having a concave portion into contact with the tip 4i18I+, a convex protrusion is formed on the upper support frame, and at the same time, the porous bridge is fixed by the convex protrusion. To easily and reliably fix a porous bridge on an upper support frame without forming protrusions for supporting the porous bridge on the upper support frame or supplying thermoplastic material from the outside. I can do it. In other words, the fusing head of the present invention greatly improves conventional industrial practicality.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the fusion head used in the method for manufacturing an ion activity measuring instrument of the present invention, □ Fig. 2 is a vertical sectional view thereof, Fig. 3A, Fig. 3B, Fig. 3C Figures 3D and 3E
The figures each show a partial enlarged vertical sectional view of a partially modified example, FIG. 4 is a perspective exploded view showing an example of an ion activity measuring instrument manufactured according to the present invention, and FIG. FIG. 6 is a perspective view showing an embodiment of the method, FIG. 6 is a perspective view after assembly, and FIG. 7 is a partially enlarged vertical view thereof. 1...Body 2...Tip part 3...Concave part 4...Screw 1
0...Lower support frame 20...Ion selection electrode pair 21...One ion selection electrode 22...Other ion selection electrode 30...Water impermeable member layer 31...One penetration Hole 32...other through hole 4
0... Upper support frame 41... One spotting hole 42
...The other spotting hole 48...The convex projection 49 on one side
...The other convex projection 50...Porous bridge (strand bridge) Fig. 3C Fig. 3D Fig. 3E Fig. E

Claims (7)

[Claims] (1) An upper support frame made of a thermoplastic material provided with at least one pair of spotting holes, and a sample liquid spotted on one of the pair of spotting holes and a reference liquid spotted on the other pair of spotting holes are electrically connected to each other. at least one porous bridge in communication with the at least one porous bridge;
A method for manufacturing an ion activity measuring device having a pair of ion-selective electrodes, wherein both ends of the porous bridge are placed at opposite positions sandwiching the pair of spotting holes, and at least one tip is provided with a recessed portion. a fusing head having a convex shape connected to a fusing energy source, the concave portion contacting both ends of the porous bridge and a portion of the upper support frame on which the ends are located; A method for manufacturing an ion activity measuring instrument, characterized in that protrusions are formed and both ends of the porous bridge are fixed by the convex protrusions. (2) The method according to claim 1, wherein the fusion energy source is a heat source. (3) The method according to claim 1, wherein the fusion energy source is an ultrasonic source. (4) A welding head having at least one tip that contacts a thermoplastic material and connected to a welding energy source to perform welding of the thermoplastic material; A welding head characterized in that a concave portion forming a convex projection is provided at the tip portion. (5) an upper support frame in which the thermoplastic material is provided with at least one pair of spotting holes; at least one porous bridge having both ends thereof fixed in contact with a part of the upper support frame; and the upper support frame of an ion activity measuring instrument having at least one pair of ion-selective electrodes. (6) The fusing head according to claim 4, wherein the fusing energy source is a heat source. (7) The fusing head according to claim 4, wherein the fusing energy source is an ultrasonic source.