JPS62177446A - Instrument for measuring ionic activity - Google Patents

Abstract

PURPOSE:To measure a blood sample without errors by supplying each of the liquid to be inspected and reference liq. to the 1st electrodes and 2nd electrodes, providing porous liquid distributing members to the respective electrodes and using non-woven cellulose fabrics as the distributing members. CONSTITUTION:The liquid to be inspected and reference liq. are supplied to each of spotting holes 36 of an upper cap 35 and are stored in a liquid storage tank 34. A fiber bridge 38 is provided between the two spotting holes 36. The porous liquid distributing members 32 are provided under the tanks 34 and the respective liquids are passed through the members 32 so as to flow into the holes 31 of a water impermeable sheet member 30. The liquid to be inspected and reference liq. are passed to a sheet-shaped solid electrode pair 26 having an ion selection layer atop the same. Connecting terminals 27 are provided to the electrodes 26 and a potential difference between the ion selective electrodes 26 is detected to measure the ionic activity. The non-woven fabrics consisting of long fiber cellulose are used as the porous liquid distributing members 32. Since the non-woven fabrics are used for the distributing members 32, the measurement error arising from the hemolysis generated in the stage of measuring the potassium ion activity in blood is eliminated.

Description

Detailed Description of the Invention [147 Fields of the Invention] The present invention relates to potentiometrically measuring the activity (or concentration) of specific ions in aqueous fluids, particularly biological fluids (blood, urine, saliva, etc.). This invention relates to an ion activity measuring instrument for quantitative analysis.

[Background of the invention] Using the droplet volume of liquids (tap water, river water, sewage, industrial wastewater, etc.) and biological fluids (blood, urine, saliva, etc.), the activity of specific ions contained therein is calculated as a sheet. A method for determining Ul using an ion activity measuring instrument is already known.

That is, a reference liquid and a test liquid are applied to the surface of each ion selection layer of a pair of ion-selective electrodes that are electrically separated from each other, and then both liquids are electrically connected to each other by a bridge. This method measures the potential difference between ion reduction electrodes to measure the ionic activity of the test liquid. Examples of such ion activity measuring instruments include JP-A-52-142586 and JP-A-56-6148.
For example, the ion activity measuring instrument described in Japanese Patent Application Laid-open No. 58-211048 and the like can be mentioned.

These ion activity measuring instruments basically have a pair of sheet-like ion-selective electrodes arranged with the ion-selective electrode facing upward, and a liquid spotting hole (f1 for standard solution and test solution) The reference solution and test solution are applied from above onto each ion 3'A selection layer using a pipette or the like through the liquid spotting hole, and both ions are selected. Ion activity is measured by measuring the potential difference generated between the electrodes. On the other hand, the activities of several types of ions can be measured by incorporating multiple sets of ion J2u selective electrode pairs into one ion activity measurement device and applying the reference solution and test solution once each. This was published in Japanese Unexamined Patent Application Publication No. 58-
It is known as No. 211648.

Although the above-mentioned method of measuring the ion activities of several species at the same time using multiple C-shaped ion-selective electrode pairs is a simple and excellent method, it has been found that there are the following problems. .

In other words, when a topical bandage, linen fabric, cold cloth, rug, filter paper, etc. are used as a porous liquid distribution member, whole blood, diluted whole blood, or similar blood containing blood cells (especially red blood cells) can be used. The ion activity in the sample, especially the potassium ion activity, is
, pl, the blood sample undergoes hemolysis within the ion activity measuring instrument, which often results in the measured value of potassium ion activity being different from the true potassium ion activity in the blood sample. This was detected as a discrepancy with the ion activity measured in plasma or serum obtained by removing blood cells from the same blood sample.

On the other hand, if pharmacopoeial gauze is used as a porous liquid distribution member, hemolysis of whole blood is relatively small, but it is easily deformed and is very difficult to cut to a certain size.

Synthetic polymer fabrics, such as polyester fabrics, cause less hemolysis of whole blood, but the liquid spreads slowly.

These materials are therefore not suitable for use as liquid distribution members in ion activity measurement devices such as those described above for measuring the ion activities of multiple species substantially simultaneously using a single device.

[Purpose of the Invention] An object of the present invention is to provide an ion activity measuring instrument that easily eliminates measurement errors due to the above-mentioned hemolysis that occurs when measuring potassium ion activity in blood samples containing blood cells such as whole blood. It is in.

The object of the present invention is to provide an ion activity measuring device useful for substantially simultaneously measuring the ion activities of multiple species in a blood sample containing blood cells such as whole blood using one device, An object of the present invention is to provide an ion activity measuring instrument that quickly eliminates measurement errors due to hemolysis when determining the ion activity pJll.

The object of the present invention is to provide a pair of ion-selective electrodes that selectively respond to specific ions, a porous liquid distribution member capable of supplying a test liquid to a first electrode of the pair of electrodes, and a porous liquid distribution member that can supply a test liquid to a first electrode of the pair of electrodes. a porous liquid distribution member capable of supplying a reference liquid to the second electrode of the pair, and a porous bridge for achieving electrical continuity between the test liquid and the reference liquid supplied to each electrode. This has been achieved by an ion activity measuring device characterized in that the liquid distribution member is a nonwoven fabric made of long fiber cellulose.

Another object of the present invention is to provide a pair of ion-selective electrodes that selectively respond to specific ions, and a porous liquid distribution member capable of supplying a test liquid to the first electrode of the pair of electrodes. , a porous liquid distribution member capable of supplying a reference liquid to the second electrode of the pair of electrodes, and a test liquid supplied to each electrode together;
An ion activity measuring device comprising a porous bridge for achieving electrical continuity with a liquid, the device comprising at least two pairs of the ion-selective electrodes, and the liquid distribution member being made of a nonwoven fabric made of long-fiber cellulose. This was achieved by an ion activity measuring instrument having the following characteristics.

The nonwoven fabric made of long-fiber cellulose is preferably a cellulose-based spunbond nonwoven fabric that does not substantially contain a binder, and is particularly preferably made of long fibers made from cotton linters. Preferably, the nonwoven fabric is produced by a spunbond method from a dissolved spinning solution.
Generally, at least 10 times the weight of the member can be absorbed in 3 seconds.

The thickness of the porous liquid distribution member used in the present invention is approximately 100μ.
Approximately 400μ to 400μ is appropriate.

The porous liquid distribution member used in the present invention is disclosed in Japanese Patent Application No. 59-2
It can also have a shape as described in No. 44200.

The ion activity measuring instrument of the present invention can take various specific embodiments, and for example, it can be of the j:4 structure described in JP-A No. 58-211648. for example,
As shown in FIG. 1, a sheet-like solid electrode (pair 26) having an ion-selective layer on its upper surface, an electrical connection terminal part 27, a support frame 28 for housing a plurality of solid electrode pairs (pairs), A water engineering 3S sheet member 30 for covering, a liquid supply hole 31 provided in the water-impermeable member 30, a porous member 32 that distributes liquid to the liquid gt supply hole 31, and a 2 for receiving the test liquid and reference liquid, respectively. A top lid 35 having two liquid storage Pa 34, a spotting hole 36 and an air vent hole 37, and a porous bridge 38 made of fiber that communicates between the spotting holes 36 are provided.

JP-A-60-155960, JP-A-60-26084
No. 3, JP-A-60-260844-fl written on the bow
It can also be made from IT.

Further, the structure described in Japanese Patent Application No. 60-148564 can be used. For example, as shown in FIG. 2, a pair of sheet-like solid electrodes 11 a, 1 lb, llc, and a spotting hole 12 having an ion-selective layer on the lower surface and electrical connection areas at both ends.
and an air vent hole 17, and a plurality of solid 'rrbf! An upper frame body 18 that houses the pair, a porous bridge 19 made of fibers that communicates between the spotting holes 12, and a water-impermeable seal member 2 provided in contact with the lower surface of the ion-selective layer of the solid electrode pair.
0, liquid supply hole 13.15 provided in water-impermeable member 20
a.

15b, 15c, liquid supply hole 15a, 1.5L+, 15c
A porous member 16 for distributing liquid to the recess 14 and a lower frame 21 for accommodating the porous liquid distributing member 16 in the recess 14 are provided. Members excluding the solid electrode pairs 11a, llb, llc, the upper frame 18, the porous bridge 19, the water-impermeable sheet member 20, and the porous liquid distribution member 16 (including liquid supply holes, recesses, etc.)
One pair each is provided for the test liquid and the reference liquid.

The ion activity measuring device 2) of the present invention is also used in Japanese Patent Application No. 60-1
No. 80358, Patent Application No. 180359, Patent Application No. 1983
It is also possible to have a structure as described in Japanese Patent No. 0-180360.

The ion activity ri measuring instrument of the present invention can also have a structure as shown in FIG. In the figure, 31 a, 3
1 b, 31 c is a sheet-like solid T having an ion selective layer on the lower surface, pole pairs; 38 is an upper frame having spotting holes 51 and housing a plurality of solid Th pole pairs; 39 is a spotting hole 51; A porous bridge 40 made of fibers that connects the solid electrode pair is a water-impermeable member provided in contact with the lower surface of the ion-selective layer of the solid electrode pair, and the water-impermeable member 40 has liquid supply holes 33'. , 35
a, 35b, and 35c are provided. 36 is a porous member that distributes the liquid to the liquid supply holes 35a, 35b, and 35c;
Reference numeral 11 denotes a lower frame body which accommodates a porous liquid distribution member 36 consisting of four parts in a recessed part 34. Further, the lower frame body 41 is provided with air vent holes 37a and 37b. The three porous bridges may pass through positions eccentric from the center point of the liquid supply hole.

To measure C-on activity using these ion activity measurement instruments, use the 3111 ion-selective electrode pairs as selective electrode pairs for sodium, potassium, and chlorine ions, and separate the reference solution and test solution. When the reference liquid and the test liquid are applied to the liquid spotting hole, the reference liquid and the test liquid permeate the porous liquid distribution member, and are supplied to the surface of each ion-selective electrode through the liquid supply hole provided in the water-impermeable member. be done. As a result, a potential difference is generated between the pair of ion-selective electrodes, and the potential difference can be measured with a potentiometer via electrical connection regions provided at both ends of the pair of ion-selective electrodes.

As a one-body ion selective electrode, Japanese Patent Application Laid-Open No. 58-21164
No. 8, 17iJ No. 1983-237351, JP-A-1983
-237352, JP-A-61-7460, JP-A-6
No. 1-7461, Japanese Patent Application Publication No. 1-7462, Patent Application No. 1983
The ion selective electrode described in No. 232306 can be used.

The ion selective electrode can be manufactured by the method described in JP-A-58-10214G, JP-A-58-156848, and JP-A-60-243555.

[Example 1] (Hemolysis degree ratio 91) The following (
Table 1) Size 1.8crnX4C1 made of material ↑Ei
Each of the n distribution members was placed in a centrifuge tube for plasma separation, and 500 μl of heparinized whole blood was added to each tube. After standing for 1 minute, the distribution member was removed and centrifuged 1IIA to obtain plasma. Table 1 shows the results of measuring the concentration of potassium ions in the blood plasma using a flame photometer (Corning Model 460).

From Table 1, it can be seen that the medical bandage Lapier S has good spreadability with whole blood, but the degree of hemolysis is large.

Table 1 shows that Benliese (:S 303) and 100% polyester cloth had a low degree of hemolysis, but the 100% polyester cloth was difficult to separate, and the spreadability of whole blood was not sufficient. Not only is it small, but it can also be easily cut to specified dimensions.

The development was also fast.

[Example 2] (Measurement of potassium ion concentration) A potassium ion selective electrode was incorporated in the center position of the ion activity measuring device disclosed in Figure 1 of Japanese Patent Application No. 1987-244199, and the concentration shown in the table below was incorporated. A multi-item ion activity measurement device was created using the distribution. 50 μl of heparinized whole blood was used as the sample solution, and the reference solution was Caliplate Level-2 (Warner-Lambert Co., potassium ion concentration 4.91).
Table 2 shows the results of measuring the potential value of the potassium ion selective electrode one minute after spotting using 50 μl of 11ea/l).

Table 2 In Table 2, the cellulose fibers f, Ii according to the present invention
The nonwoven fabric showed that the measured potassium ion concentration in whole blood was approximately equal to that measured in plasma, indicating less dissolution.

[Example 3] Using Benliese G5303 as the four liquid distribution members 36 of the ion activity measuring device shown in FIG. 3, a multi-item ion activity measuring device was manufactured by f1τ. Caliplate Level-2 (Warner-Lambert Co., Ltd. potassium) was used as a reference solution.
Ion concentration 4.9 meq/I) 50μ! Whole blood collected with heparin or plasma after centrifugation using
Using 0 μl as a sample solution, the potassium ion concentration was measured. As a result of measuring the potassium ion concentration for each 100 sample solutions, the measured value for whole blood and plasma was 0.5 meq/
There was no deviation of more than I.

[Brief explanation of drawings]

FIGS. 1, 2, and 3 are exploded perspective views showing embodiments of the ion activity measuring instrument of the present invention. Applicant: Fuji Photo Film Co., Ltd. II!
I

Claims (6)

[Claims] (1) a pair of ion-selective electrodes that selectively respond to specific ions, a porous liquid distribution member capable of supplying a test liquid to a first electrode of the pair of electrodes, and a second electrode of the pair of electrodes; An ion activity measuring device comprising a porous liquid distribution member capable of supplying a reference liquid to each electrode, and a porous bridge to achieve electrical continuity between the test liquid and the reference liquid supplied to each electrode. An ion activity measuring instrument characterized in that the liquid distribution member is a nonwoven fabric made of long fiber cellulose. (2) The ion activity measuring instrument according to claim (1), comprising at least two pairs of ion-selective electrodes. (3) The ion activity measuring device according to claim (1), wherein the liquid distribution member is made of long fibers made from cotton linters. (4) The ion activity measuring device according to claim (1), wherein the liquid distribution member is a cellulose spunbond nonwoven fabric that does not substantially contain a binder. (5) The ion activity measuring device according to claim (1), wherein the liquid distribution member is a nonwoven fabric manufactured by a spunbond method from a spinning solution obtained by dissolving cotton linters in Schweitzer liquid. (6) The ion activity measuring device according to claim (1), wherein the liquid distribution member is a porous member that absorbs at least 10 times the weight of blood in 3 seconds.