JPS62147354A - Method for detecting abnormality of measurement - Google Patents

Abstract

PURPOSE:To make it possible to judge that a measuring instrument was not normal on the spot, by a method wherein measurement is repeated at an appropriate time interval over a definite time from the point of time when a liquid to be measured was contacted with the measuring instrument and this measurement is judged to be abnormal when the change quantity of the measured value exceeds a predetermined limit. CONSTITUTION:A liquid or gas to be measured is contacted with a measuring instrument determining the concn. or activity value of the specific substance in the liquid or gas to be measured according to a physical or chemical method. Measurement is repeated at an appropriate time interval over a definite time from the point of time of contact. When the change quantity of the measured value exceeds a predetermined limit, said measurement is judged to be abnormal to judge that the used measuring instrument was not normal. Especially, in measuring the activity of the ion in the liquid, the abnormality of the measuring instrument can be simply detected.

Description

[Detailed Description of the Invention] [Field of the Invention] The present invention relates to the measurement of various physical or chemical quantities such as the content and activity value of various components in liquids or gases. Regarding how to identify whether or not. In particular, the present invention relates to a method for easily detecting abnormalities in a measuring instrument when measuring the activity of a single ion in a liquid.

[Background of the invention]

Alcohol and sugar contained in beverages such as alcoholic beverages; Chlorine, oxygen, and various ions contained in tap water, sewage, and wastewater; Blood (plasma, serum 1.I!I! liquid, urine, etc.) Metabolites, such as carbohydrates, lipids, hemoglobin, bilirubin, creatinine 1. Uric acid, or various ions such as potassium, sodium, calcium, chlorine, carbonic acid, etc.; indoor air, exhaust air, exhaled breath, air in containers, etc. When measuring the concentration of various substances contained in liquids and gases, such as oxygen, carbon oxide, carbon dioxide, ammonia, and water, using various physical and chemical methods, or measuring the concentration of substances contained in biological fluids, When determining the activity of an enzyme using chemical or physicochemical methods, it is important to determine whether the measurement means used is working properly and giving correct results in terms of reliability of the measurement. This is an important issue.However, with many measurement methods, such judgment is often difficult.

Among the various measurements mentioned above, there is a method that electrochemically measures the activity of ions and the activity or concentration of various substances using an ion-selective electrode using an ion-selective membrane or a sensor using a field-effect transistor. The major advantages of this method are that it has high sensitivity and can be carried out quickly and easily, but there are concerns about the reliability of the measured values. Especially at the start of the measurement (contact with the sample)
In many cases, the potential value changes gradually or rapidly from the time when the concentration or activity value is determined, and it is common practice to use the amount of change as the potential difference fC when this change becomes stable. However, the a-pole and sensor are often updated each time they are measured (so-called disposable), and the characteristics of temporal potential change vary from individual to individual, so the obtained results may vary depending on the electrode or sensor. I'm not sure if this is a result of normal operation.

In measurements that are accompanied by such concerns, it would be extremely convenient if it could be determined in each individual measurement whether the measuring instrument was operating normally and the correct measured value was being returned.

[Purpose of the invention]

When measuring the concentration or electrochemical or biochemical activity value of a specific substance in a liquid or gas using a physical or chemical method, the ratio measuring instrument used operates normally and provides correct results. The goal is to provide a method that allows you to judge on the spot whether or not it is.

In particular, the object of the present invention is to provide a method for determining on the spot whether or not the measuring instruments used, such as electrodes and sensors, are operating normally when measuring using electrochemical means.

[Summary of the invention]

The purpose of the above is to use a liquid to be measured (including not only a sample but also a reference solution and a standard solution) as a measuring instrument that determines the concentration and activity value of a specific substance in a gas by physical or chemical methods. )
Measurement is carried out at appropriate time intervals for a certain period of time from the time of contact with the gas to be measured.
Abnormality identification of a measuring instrument, characterized in that when ATL is repeated and the amount of change in the measured value exceeds a predetermined limit, the measurement is determined to be abnormal, and the measuring instrument used is determined to be normal and a friend. Just in case it is achieved by the method.

[Specific structure of the invention]

Calculate the activity of specific ions contained in a small sample of liquid (tap water, river water, sewage, industrial wastewater, etc.) or biological body fluid (blood such as whole blood, plasma, serum, urine, saliva, etc.) A method for measuring ion activity using a sheet-shaped ion activity measurement device is already known.

That is, a reference liquid and a test liquid are applied to the surface of each ion-selective layer of a pair of sheet-like ion-selective IT electrodes that are electrically separated from each other and have ion-selective layers on the top,
Next, in a state where both liquids are electrically connected to each other by a bridge, the potential difference between each ion selection electrode is measured, thereby measuring the ion activity of the test liquid.

Such an ion activity measuring instrument is, for example, disclosed in Japanese Patent Application Laid-open No.
/! JJ-r4 publication (US p, or3°311)
(US stands for United States patent), Tokukaisho! ≦-A/II
It is described in Publication No.-1 (US!, 273.t391, etc.).

These ion activity measurement instruments basically consist of a pair of sheet-shaped ion-selective pentode arranged with the ion-selective layer facing upward, and a liquid spotting hole (for application of standard solution and test solution) on top of the pentode. The reference solution and test solution are applied from above onto each ion-selective layer using a bit, etc., through the liquid spotting holes, and both ions are applied. Ion activity is measured by measuring the potential difference generated between selected electrodes. Furthermore, as an improved version of the ion activity measurement device described above, a plurality of ion selection electrode pairs are incorporated into the ion activity measurement device, and the reference solution and the test solution are applied once each. Yo! 7 JP-A-Sho also has a device that can measure the activity of multiple types of ions! I-,2
It is known from Publication No. 64.

When using an ion activity measuring instrument using such an ion selective electrode, the potential measuring system may not be formed correctly.

There are three main examples:

■ The test solution or reference solution is not placed in the correct position. Or the amount of liquid applied is small.

■ The ion activity measuring device (ion selective electrode, bridge, etc.) is defective.

■ If the contact between the connection terminal of the ion selection electrode and the measurement probe is poor.

In such a case, false measurement results will be given, so it is necessary to detect these abnormalities and notify the measurer. The need for such abnormality detection exists not only when using sheet-like electrodes, but also when using rod-like electrodes or wire electrodes.

Such an abnormality can be detected by applying the test solution and reference solution to the ion activity measurement device, measuring the potential difference at appropriate time intervals over a certain period of time, and measuring the amount of change in this potential difference based on a predetermined amount. When the limit is exceeded, the measurement is judged as abnormal,
We discovered that it is possible to detect and take action on the spot by determining that the ion-selective electrode used is not normal.
Ion activity measuring instruments to which the present invention can be applied include not only the sheet-like ion-selective electrode pair described above but also various types of ion-selective electrodes. For example, U.S. Patent J, 19
1,1Ar No. 2 (inventor Neff), U.S. Patent 3,70
No. 7,4tJJ- (inventor Derr), US Pat. No. 3.
/II-, No. 137 (inventor Arthur), U.S. Pat.
r), U.S. Patent 3. Bu, 5'/, No. 201 (inventor Du
Ckaberry), U.S. Pat. No. 2,101,223 (
Inventor Perle3'), JP-A-3-7-/l/! lI
-A wide variety of issues, including JP-A-Sho Jr./A4 issue.

Furthermore, the measuring instrument to which the present invention can be applied is not limited to an ion live fish measuring instrument, but may also be an electrochemical measuring instrument using a field effect transistor, for example.

For example, Tokuko Shoj7-Hiroshi 3r63, Tokuko Shoj7-1A
2/17 issue, Tokukai Sho! It is described in No. I-J4cJ12 and is as follows.

Furthermore, the present invention utilizes the electrical conductivity of a porous membrane on which an enzyme is immobilized to produce a subsequent enzyme activity measuring instrument, such as the one disclosed in Japanese Patent Application Publication No. 2003-100003. 7-2I10j
It can also be applied to those listed in Hirogo.

Other measuring instruments using enzyme electrodes, such as Tokuko Shoyo 7-! 40/'? Alcohol concentration measuring instruments described in the Japanese Patent Application Publication No. 7-1776 Tata, Japanese Patent Application Publication No. 5R-RA
≠λ issue, Tokukai Sho! It can be applied to the measurements described in r-IA Kou No. 3, etc.

The present invention can also be applied to quantitative detection of specific components contained in gas. For example, Jitsukiaki, tr-, 214207
It can also be applied to the analysis of ammonia gas described in .

The actual operating procedure is, for example, as follows.

For example, fc
An ion activity measuring instrument for simultaneously measuring the ion activities of Na+, K+, and α-3 is connected to the potentiometer.

A sample solution and a reference solution are respectively placed in the two openings of the ion activity measurement device, and the potential is measured and recorded using a potentiometer, for example, after 60 seconds and 75 seconds.

In this example, if the difference between the potential difference measurements after 40 seconds and 7j seconds exceeds, for example, o, zmv, it is determined that this measurement is abnormal. If the ion live fish measuring device is replaced with a new one every time it is measured, it should be determined that the ion activity measuring device is abnormal and should be replaced with a new one. Then, repeat measurements using the same sample solution and the same reference solution. 60 seconds later and 7
The difference in potential value after j seconds is 0. If it is less than jmV, this result is adopted. This makes it possible to eliminate abnormal measurement instruments and measurement results and obtain correct ion activity measurements.

This operation may be performed in the same manner even if the ion activity measuring instrument is of another type, or even if it is an electrochemical concentration or activity measuring instrument other than the ion activity measuring instrument.

Another example is Tokkai Sho! A sample solution containing glutamate-pyruvate transaminase (GPT) was spotted using the multilayer analytical element for transaminase activity measurement described in Example 3 of No. 7-2O♂Re-9, and the color concentration was measured over time. At this time, the color densities of 7112 minutes, 3 minutes, and ≠A are measured, and the differences therebetween are defined as V2 and V4.

D(3'1-D(/歿/) == V2D(Hongshu')
+ -D (J' l =v4V4 is used to measure the activity using a GPT calibration curve, and from the correlation between v2 and ■4 and its fluctuation, it is found that v2 is within the normal value range (danger! σ) in relation to v4. ) is determined. When ■4 is determined, if correspondingly ■2 is not within the normal range, it is determined that there is an abnormality in one analytical element.

Other physicochemical and chemical methods (if physical measuring means are used, electrochemical measuring instruments and potentiometers may be replaced by corresponding measuring instruments and measuring devices (e.g. sliding colorimetric instruments). The analysis element and the optical density measuring device, the test piece and the surface temperature measuring device, etc.) may be used in combination.

[Effects of the present invention]

The effects of the present invention include the following effects in addition to achieving the above-mentioned objects of the present invention.

Japanese Patent Application Laid-open No. Sho zg'-t, rztr describes a method for determining the deterioration of an ion-selective electrode by the change in capacitance between the ion-selective electrode and the counter electrode. By measuring the impedance of a potential measurement system including an ion-selective electrode,
A method for detecting abnormalities in a potential measurement system is described. These methods require the addition of special circuitry to detect electrode deterioration. On the other hand, the present invention does not require the addition of any special circuit and can detect abnormalities using only ordinary measuring instruments.

〔Example/〕

As shown in Fig. 1, the 7j Na, K, and CI three types of ion active measurement device (% Gansho AO-/≠rrta No. 3
) and an electrometer (Orion MIC
RO-PROCESSORl0NANALYZERrio
i) was connected via a contact switch. A reference solution and standard sample solution with the concentrations shown in Table 1 were prepared (the standard sample solution was American Ho5pitalSupply).
Corp., Inc., Mon1trol-II) 10 μt of the reference solution in Table 1 was added to one of the solution application openings of the measuring instrument, and the sample solution of the standard sample solution was added. θμt was spotted on the other opening almost simultaneously, and the time change of the generated potential was tracked with an electrometer, and the potentials were recorded after to seconds and after 7j seconds.

The results are shown in Table 2. Among the 100 measuring instruments, the difference between the l''l:Na ion potential after to seconds and after 7j seconds was less than o,rmV for the tatata sheets, but for the 7th sheet, it was j, OmV. The measured value of the Na ion potential itself also showed an extreme difference from the theoretical value.

[Example]

Using the same measuring device as in Example/, Na ion/Tade m-mot/j, K ion 1. /m-mot/l
, (21-ions/30m mo!, /l) Using standard sample solution-2 containing ions/30m mo!, /l and the same reference solution as used in Example/, each of the 20 ion activity measurement instruments was spotted. The potential difference after 30 seconds, 1 seconds, and to seconds was recorded.As a result, 1.20 ion activity measuring instruments were used.
For the 7th sheet, the difference in potential values after 30 seconds and after 30 seconds for all Na'', K+, and α- ions was within /mV, but only for the 7th sheet. is 20m
It was close to V.

Table 3 shows the top values at each time point regarding the number of VCs considered normal and the number of VCs considered abnormal.

From this result, K1! 30 seconds later, Hiro! The difference after seconds is /
The ion activity measuring device that greatly exceeds rnV is J(+ potential measurement value itself is abnormal compared to other pieces, K
The ion selective electrode part was abnormal. Therefore, 30
Seconds later and Hiro! By setting the potential difference within /mV after a second as a limit value, it is possible to detect an abnormality in the ion activity measuring instrument and take measures such as not adopting the measured value.

[Brief explanation of drawings]

The vortex/figure is a conceptual diagram of a friend ion activity measuring device used in Examples. The meanings of the symbols in the diagram are as follows. /, ion activity 1] measuring device a, probe 3, contact cutter, potential '1llll measuring device Fig. 1 shows an exploded view of the internal structure of the ion activity measuring device used in the examples. This is an 8+ view. In the figure, 3/a row 3/b row 3/c is an ion selective electrode pair, 33
3 indicates a spotting hole, 36 indicates a liquid distribution member, and 3 indicates a bridge. Patent applicant Fuji Photo Film Co., Ltd. Figure 2 Procedural amendment 1, case description Showa to year patent application No. 219!19
No. 0 2, Title of the invention Method for detecting abnormality in measurement
(3. Relationship with the case of the person making the amendment Patent applicant address: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture (, Subject of amendment: "Detailed Description of the Invention" column of the specification and drawing 5, Contents of the amendment (1) The ``theoretical value'' on page 13 of the specification is corrected as ``predicted value.'' (3) Correct the "theoretical value" in the bottom row of Table 3 on page 1, page 1, with "predicted value." (4) Correct the figure 1 of the drawing as shown in the attached sheet. .

Claims (1)

[Claims] A measurement device for determining the concentration or activity value of a specific substance in a liquid or gas by a physical or chemical method includes a liquid to be measured (including not only a specimen but also a reference liquid and a standard liquid). ) or repeat measurement at appropriate time intervals for a certain period of time from the time of contact with the gas to be measured, and if the amount of change in the measured value exceeds a predetermined limit, this measurement is judged to be abnormal. A method for identifying an abnormality in a measuring instrument, characterized by determining that the measuring instrument used is not normal.