JPH09127040A - Method and apparatus for measurement of concentration of oils and fats - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the concentration of oils and fats in real time and simply by a method wherein mineral oils or animal or vegetable oils contained in an object to be measured are emulsified, a sensor which uses a lipid membrane is immersed and their electric characteristic is measured. SOLUTION: A lipid membrane sensor is immersed for about 10 hours in a reference solution in which a surface-active agent is added to pure water, a surface-active agent of the same kind is added, to be the same concentration, to a sampled object to be measured, and the surface-active agent is stirred so as to be emulsified. The lipid membrane sensor is put into, and taken out from, a reference solution for cleaning about 10 times, it is immersed in a reference solution for measurement for about 20 seconds, and a sensor potential is measured. This operation is repeated a plurality of times, the sensor is taken out from the reference solution after the change in the sensor potential has become a prescribed range, and it is cleaned by a sample solution for cleaning. The sensor is immersed in a sample solution for measurement, and the sensor potential is measured after about 20 seconds. The above operation is repeated a prescribed number of times, and the concentration of oils or fats is computed by a multivariable analytical operation, a pattern recognition operation or the like on the basis of the potential of a multichannel sensor. Thereby, the concentration can be measured simply and in real time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring the concentration of metal ions and organic substances contained in river water and industrial water by utilizing a sensor using a lipid membrane, that is, to a water quality monitoring and the like. TECHNICAL FIELD The present invention relates to a technology that can be used, and particularly to a technology that measures the concentration of mineral oil and animal and vegetable oils and fats (hereinafter referred to as oils and fats) among organic substances.

[0002]

2. Description of the Related Art Conventionally, for example, when quantifying fats and oils contained in industrial water, "26. Hexane extract substance" in "26. Hexane extraction substance" of "JIS K 0101" which defines a test method for industrial water. .2 extraction method ”. In this method, the sample is acidified with hydrochloric acid of pH 4 or less, extracted with hexane (n-hexane), then hexane is stripped at 80 ° C., and the mass of the remaining substance is measured to quantify the hexane extracted substance. The purpose is to quantify oils and fats that are difficult to volatilize.

[0003]

In the above-mentioned hexane extraction method, in addition to fats and oils, those which are difficult to volatilize extracted in hexane are included in the quantitative value, and the measurement takes time and labor, There was a problem such as. Various measurements
With the progress toward real-time and electronics, no suitable sensor or measurement method has been found for measuring oils and fats mixed in water. An object of the present invention is to provide a method and apparatus for measuring the concentration of fats and oils contained in industrial water easily in a short time, that is, in real time in practice.

[0004]

In order to solve the above-mentioned problems, firstly, a sensor using a lipid membrane (hereinafter referred to as a lipid membrane sensor) irrespective of the conventional analytical chemistry method. Secondly, in order to enable measurement with a lipid membrane sensor, it was decided to pretreat the measurement target. That is, the first invention is a step of pretreatment in which fats and oils and the like contained in the measurement target are dispersed in the measurement target, and an emulsion (emulsion: emulsion, emulsion, liquid small particles) is generated by the pretreatment. The lipid membrane sensor is immersed in a solution to be measured that has become a system in which the liquid is dispersed in another liquid that does not dissolve, and its electrical characteristics (potential, impedance,
Etc.) is measured. A second aspect of the invention is a stirring means for emulsifying a measurement target, a lipid membrane sensor for measuring a solution to be measured which is stirred to form an emulsion, and an oil or fat by receiving an output signal of the lipid membrane sensor. And a signal processing means for outputting a signal containing information on the concentration of the light.

Here, a lipid membrane sensor, a measuring system and a measuring method using the same will be described. The inventors of the present application have noticed that the lipid membrane sensor is useful as a taste sensor,
A number of inventions have been completed since 1989 (Japanese Patent Application No. 1-190819, Japanese Patent Application No. 2-176584, Japanese Patent Application No. 3-020450, Japanese Patent Application No. 4-194949,
Japanese Patent Application No. 5-252546, Japanese Patent Application No. 7-94359,
etc).

[0006] Among them, in Japanese Patent Laid-Open No. 3-54446, a lipid substance composed of a molecule having a hydrophobic portion and a hydrophilic portion is fixed in a matrix of a polymer and the surface thereof is fixed. A lipid molecular membrane (lipid membrane) having a structure in which hydrophilic portions of lipid molecules are aligned is a sensor for horse mackerel (measurable taste or difference in taste (comparative or contrasting taste), that is, human taste. It was shown to be a taste sensor that can be used instead of.

FIG. 5 is a diagram showing the membrane formula of the lipidic molecular membrane by the expression method used in the method of designing chemical substances. The globular part shown by a circle in the lipid molecule is a hydrophilic group a, that is, a hydrophilic part a, and there is a hydrocarbon chain structure b (for example, an alkyl group) whose atomic arrangement extends long from it. In each case, two chains are extended to represent one molecule in each case, and the whole constitutes a molecule group. This part of the hydrocarbon chain is the hydrophobic site b. Such a lipid molecule group 31 is partly dissolved in the matrix 33 (surface structure, microscopic structure having a planar spread) on the surface of the membrane member 32 (eg It is accommodated at 31 ') in FIG. The manner of its containment is
The hydrophilic sites are arranged on the surface.

FIGS. 6 (a) and 6 (b) show a multi-channel taste sensor using this lipidic molecular film. In this figure, three sensitive parts of the multi-channel array electrode are shown. In the illustrated example, a 0.5 mmφ hole was penetrated through the base material, and a silver rod was inserted into the hole to form an electrode. The lipidic molecular film is attached to the substrate so as to contact the electrode via the buffer layer.

FIG. 7 shows a horse mackerel measuring system using the multi-channel taste sensor. Prepare an aqueous solution of the taste substance, use it as the solution to be measured 11, and place it in a container 12 such as a beaker.
Put in. The taste sensor array 13 formed by arranging a lipid membrane and electrodes on an acrylic plate (substrate) as described above was placed in the solution to be measured. Before use, potassium chloride 1m
The electrode potential was stabilized with a mole / l aqueous solution. 14- in the figure
1,..., 14-8 indicate the respective lipid membranes by black dots.

A reference electrode 15 is prepared as an electrode for generating an electric potential serving as a standard for measurement, and the reference electrode 15 is put into a solution to be measured. The taste sensor array 13 and the reference electrode 15 are installed at a predetermined distance. The surface of the reference electrode 15 is covered with 100 m mole / l of potassium chloride solidified with agar as the buffer layer 16, so that the electrode system is eventually silver 2 | silver chloride 4 | lipid film 3
(14) ｜ Measured solution 12 ｜ Buffer layer (potassium chloride 100m mole
/ L) 16 | silver chloride 4 | silver 2

The electric signal from the lipid membrane becomes an 8-channel signal in the figure, and is guided to the buffer amplifiers 19-1, ..., 19-8 by the lead wires 17-1, ..., 17-8, respectively. Each output of the buffer amplifier 19 is selected by an analog switch (8 channels) 20 and applied to an A / D converter 21. The electric signal from the reference electrode 15 is also applied to the A / D converter 21 via the lead wire 18, and converts the difference from the potential from the membrane into a digital signal. This digital signal is appropriately processed by the microcomputer 22 and displayed by the XY recorder 23. In this example, an 8-channel taste sensor is used, and each channel has different response characteristics to taste in order to obtain a large amount of taste information capable of reproducing the taste of human being. It is composed of a molecular film.

[0012]

[Table 1]

Further, in JP-A-4-64053, in order to detect and measure horse mackerel with a taste sensor using a lipid molecule with good reproducibility, the same or similar azide as the sample solution to be measured is used as a reference solution. It is assumed that the taste sensor is sufficiently immersed in the reference liquid, a similar stimulus is applied to the taste sensor for each measurement, and the measurement time is after stabilization of the surface potential and the transmembrane potential is As a method of selecting when slowly changing, a method of improving the reproducibility of the measurement value by the taste sensor, reducing the variation of the measurement value, and increasing the discriminating power of the horse mackerel has been disclosed.

When the concentration of oils and fats is to be measured using the lipid membrane sensor, the sample liquid is preferably an emulsion. The required degree of emulsification depends, of course, on the purpose of measurement, accuracy and the like. For example, if it is only necessary to determine whether or not oils and fats are contained regardless of the amount, it is not necessary that the entire sample be even and homogeneous, and only the portion where the lipid membrane sensor is immersed is emulsion. That's enough. On the other hand, if an attempt is made to estimate the proportion of oils and fats contained, the accuracy of measurement will deteriorate unless the entire sample is homogeneous. The present invention can be applied to any case, and actually an emulsion does not mean that the whole sample has to be homogeneous, but means that at least a local object to be measured may be an emulsion.

As described above, it is desirable that the sample liquid be an emulsion, but most of the oils and fats and the like are unlikely to become an emulsion as they are. For this reason, when measuring the ratio of oils and fats contained in river water or industrial water, that is, the concentration, it is necessary to perform some treatment to form an emulsion. In order to dissolve fats and oils in water,
There is a method of adding a surfactant as is known in laundry washing and dish washing. However, when a molecule of a surfactant is coordinated around a molecule such as an oil or fat, the lipid membrane sensor responds to the molecule of the surrounding surfactant, and even if the concentration characteristics of the surfactant are obtained, It was expected that the results would not obtain the concentration characteristics such as. Further, it is considered that the surfactant is adsorbed on the membrane surface of the lipid membrane sensor, or the lipid in the membrane is eluted, and it is expected that the lifetime of the sensor is adversely affected.

Although the above predictions were made, the inventors have the following ideas. Since ancient times, water and oil have been regarded as metaphors for things that are difficult to integrate with each other, along with the relationship between dogs and monkeys. However, it is known that, for example, under ultrasonic vibration, they will dissolve in each other for a certain period of time, and as with foods, such as salad dressings, the mixture of water and oil causes subtle changes in taste. It is a daily experience that egg yolk and salad oil are mixed well or not, as in the case of successful or unsuccessful mayonnaise making. Mixing oils and oils and oils and fats is also diverse. The variation becomes more complicated when the temperature change is used as a parameter. Therefore, the inventors of the present application conducted an experiment as described later on the interaction between the lipid membrane sensor and fats and oils contained in water,
It was discovered that the concentration of oils and fats in water mixed with oils and fats can be measured by treating with a surfactant. Further, depending on the type of fats and oils and the amount mixed in industrial water, it may be possible to perform the measurement by stirring with ultrasonic waves without using a surfactant. The present invention is based on the above findings.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Depending on the way in which oils and fats are mixed, detection may not be possible, so pretreatment is performed in order to reliably detect and measure. In particular, it is necessary to perform pretreatment in the concentration measurement. Since the pretreatment may be carried out by dissolving fats and oils in the object to be measured, there may be various methods, but the main ones are stirring and stirring with the addition of a surfactant as an emulsifier. Here, as an embodiment, a method of adding a surfactant and stirring and a method of adding ultrasonic waves and stirring will be described.

FIG. 1 is a flow chart of a first embodiment of the oil and fat concentration measuring method according to the first invention. A first embodiment of the oil and fat concentration measuring method according to the first invention will be described with reference to FIG. (1) Preparation stage Preparation of reference solution (reference solution) Prepare an aqueous solution (reference solution) in which a surfactant of the same type as the surfactant to be added to the measurement target is added to pure water at the same concentration as the solution to be measured. I do. Here, the reference solution is, for example, 10 mmol in pure water in order to stabilize the output of the lipid membrane sensor.
It is also possible to just add / l of KCl. In this case, 10 mmol / l KCl is also added to the solution to be measured. Immerse the lipid membrane sensor in the standard solution for approximately 10 hours.

(2) Measurement 2-1. Pretreatment Add a surfactant to the sample to be measured such as collected river water or industrial water. Surfactants include anionic surfactants (such as higher alcohol sulfates, fatty acid sulfates, and sulfonic acid type anionic surfactants), nonionic surfactants, and soaps. The amount to be added is, for example, an amount at which the fats and oils are not separated even when the surfactant is added to the solution and left standing after stirring. Depending on the measurement, a predetermined amount may be added. 2-2. Measurement with lipid membrane sensor Put the lipid membrane sensor in and out of the reference solution (for washing) 10
Do it twice. It may be said that the surface is washed with a reference solution (for cleaning), it may be said that it is immersed in the reference solution intermittently, or that the surface of the lipid membrane of the lipid membrane sensor is stimulated. Immerse in the reference solution prepared for measurement, and
After 0 seconds, the potential of the lipid membrane sensor is measured and the measured value is V0. The procedure is repeated twice or more, and for each measurement, it is determined whether the difference between the current measured value V0 and the previous measured value V0 is equal to or smaller than a predetermined value. If the difference is equal to or smaller than the predetermined value (that is, if V0 is stable), the procedure is performed. Proceed to. The lipid membrane sensor is taken out of the reference liquid (for measurement) and washed with the sample liquid (for washing). (Take in and out 10 times in the same manner as above.) The lipid membrane sensor is immersed in the sample solution (for measurement), and after about 20 seconds, the potential Vs of the lipid membrane sensor is measured. Return to the measurement procedure and repeat the procedure. The procedure is completed after repeating a predetermined number of times.

The following three methods can be considered for calculating the fat and oil concentration. (1) It is determined whether the potential of the sensor of the emulsified sample exceeds the set range, and the abnormality is detected. The multi-channel sensor has more information and the determination accuracy is improved. It does not calculate the concentration of fats and oils, but it has a great utility value.

(2) A method for calculating the oil and fat concentration by using multivariate analysis and pattern recognition from the potentials of the multichannel sensor of the emulsified sample. Similar to oils and fats, the sensor sensitivity is measured in advance for substances that the sensor is sensitive to and that change other than oils and fats. An operation model formula of the sensor is created from these sensitivities, and an inverse conversion formula (that is, a formula for calculating the concentrations of those substances) is obtained from the formula (however, only the formula for calculating the fat and oil concentration is necessary). The sensor output of the sample is put into this equation to estimate the fat concentration. In the calibration, the sensitivity of the sensor for each of the above substances is obtained, and the formula of the inverse conversion is changed.

(3) A method of calculating the oil / fat concentration from the difference in sensor potential between both the non-emulsified sample and the emulsified sample. Difference (Vse-Vs) between the sensor potential (Vse) of the emulsified sample and the sensor potential (Vs) of the sample not emulsified
Is composed of the influence of the amount of oil and fat dissolved by the emulsification and the influence of the emulsion treatment (for example, if a detergent is used for emulsification, the sensor sensitivity to the detergent). If the sample is narrowed down to a certain range, the effect of the emulsion treatment is considered to be constant, so the potential difference reflects the amount of oil and fat dissolved by the emulsification.

The effect of the emulsion treatment is that in the sample s0 containing no fat and oil, the difference (Vs0 e-) between the potential (Vs0 e) of the sample subjected to the emulsion treatment and the potential (Vs0) of the sample not subjected to the emulsion treatment.
Vs0). By subtracting the difference between the emulsified and non-emulsified samples of the above sample s0, the difference between the emulsified and non-emulsified samples s0 is only the effect of the oil concentration. Can be calculated. When the fat and oil concentration is C, the following formula is created. C = K ((Vse-Vs)-(Vs0 e-Vs0)) ... (1) Here, K is a constant. Further, in order to match the unit of the fat and oil concentration, 1 unit of fat and oil in fat and oil concentration was added to a sample containing no fat and oil, and the measured value of the sample sl was calculated by Equation 1
To determine the constant K. K = L / ((Vsle-Vsl)-(Vs0e-Vs0)) (2) That is, the fat concentration can be calculated by calculating the formulas 1 and 2. Equation 1 is a linear equation, but any monotonically increasing function may be used. There may be a quadratic expression or an exponential function depending on the relationship between the sensor and the concentration. Further, in the above measuring method, the potential of the sample and the potential of the emulsified sample may be measured by directly replacing the reference liquid with the sample (without preparing a special reference liquid).

When a surfactant is used, the amount of oils and fats and the like dissolved in the solution becomes larger than that obtained by simply stirring,
Further, the emulsion state is stable, which is advantageous for measurement. From another point of view, this means that the time required for stirring is reduced.

FIG. 2 is a flow chart of a second embodiment of the oil and fat concentration measuring method according to the first invention. In the second embodiment, stirring by ultrasonic waves is performed in the pretreatment. Since the preprocessing method is different from that of the first embodiment, and the other is the same, only the preprocessing stage will be described. The intensity of the ultrasonic wave to be applied, the application time, and the like differ depending on the object to be measured, and cannot be said unconditionally. Whether or not the oils and fats and the like have been separated must be visually confirmed, and in the case of this method, the separation of the oils and fats and the like gradually progresses as time passes after the application of ultrasonic waves is stopped.

FIG. 3 is a block diagram of the first embodiment of the oil and fat concentration measuring device of the second invention. A first embodiment of the second invention will be described with reference to FIG. The apparatus according to the first embodiment includes a lipid membrane sensor 41, a signal processing means 42,
Surfactant supply means 43, stirring means 44 and control means 45
Consists of The electrical characteristics of the membrane are output from the lipid membrane sensor 41, and the output is received by the signal processing means 42. The signal processing means 42 performs processing such as impedance conversion and calculates the oil and fat concentration in order to stably take out the output of the lipid membrane sensor 41. The solution 11 to be measured is emulsified by the surfactant supply means 43 and the stirring means 44. The control unit 45 includes the lipid membrane sensor 41, the signal processing unit 42, the surfactant supply unit 43, and the stirring unit 4.
4 is controlled. For example, the lipid membrane sensor 41 and the signal processing means 42 are controlled so that the procedure described in the measuring method is performed. In addition, the surfactant supply means 43 and the stirring means 4
4 is controlled to control the presence or absence and the degree of emulsification treatment. Although FIG. 3 shows an apparatus for measuring a sample in a batch system, a flow system is naturally conceivable when online. In this case, the emulsification process is performed by the lipid membrane sensor 4.
It is carried out at a place (cell) other than the place (cell) where 1 is immersed, and the emulsified sample is sent to the lipid membrane sensor 41 (cell) by flow and measured.

The lipid membrane sensor 41 has one channel (c) if there is no difference in the state of the object to be measured with respect to the mixing of oils and fats and the like and there is no difference in the amount of mixing with other substances.
h) is also sufficient, and the signal processing means 42 may be sufficient to receive the output of the lipid membrane sensor and output it as it is to the outside. If the state changes for other substances,
It is necessary to use a plurality of lipid membrane sensors with different responses to extract only the information regarding the mixing of oils and fats.

FIG. 4 is a block diagram of the second embodiment of the oil and fat concentration measuring device of the second invention. The difference from the first embodiment of the second invention is that the surfactant supply means 43 is not provided. In this example, the object to be measured is emulsified only by stirring with ultrasonic waves.

[0029]

EXAMPLES As examples, experiments conducted by the inventors will be described. This experiment is included in the first embodiment of the first invention described in the section of the embodiment of the invention. (1) Preparation stage The lipid membrane sensor used is 7 channels (ch),
The type of lipid of each ch is shown in Table 2.

[0030]

[Table 2]

River water was sampled and used as a measurement target, and mineral oil was used as mixed fats and oils. As the surfactant, sodium linear alkylbenzene sulfonate was used. 10 mmol / l KCl was added to pure water, and this was used as a standard solution. The objects of measurement are three kinds of liquids in which mineral oil was added to the same liquid as the reference liquid at 0.1 ppm, 1.0 ppm, and 10.0 ppm, respectively. The measurement system is almost the same as the measurement system described in the section of means for solving the problem. Immerse the lipid membrane sensor in the standard solution for approximately 10 hours.

(2) Measurement 2-1. Pretreatment Two groups of the above-mentioned three kinds of liquids were prepared, 1 ppm of sodium linear alkylbenzenesulfonate was added to each of the three kinds of liquids of one group, and 10 ppm was added to each of the three kinds of liquids of the other group, followed by thorough stirring. . A total of 6 kinds of liquids thus obtained were used as sample liquids.

2-2. Measurement with lipid membrane sensor Put the lipid membrane sensor in and out of the reference solution (for washing) 10
Do it twice. It may be said that the surface is washed with a reference solution (for cleaning), it may be said that it is immersed in the reference solution intermittently, or that the surface of the lipid membrane of the lipid membrane sensor is stimulated. Immerse in the reference solution prepared for measurement, and
After 0 seconds, the potential of the lipid membrane sensor is measured and the measured value is V0. The procedure is repeated twice or more, and for each measurement, it is determined whether the difference between the current measured value V0 and the previous measured value V0 is equal to or smaller than a predetermined value. If the difference is equal to or smaller than the predetermined value (that is, if V0 is stable), the procedure is performed. Proceed to. The lipid membrane sensor is taken out of the reference liquid (for measurement) and washed with the sample liquid (for washing). (Take in and out 10 times in the same manner as above.) The lipid membrane sensor is immersed in the sample solution (for measurement), and after about 20 seconds, the potential Vs of the lipid membrane sensor is measured. Return to the measurement procedure and repeat the procedure. Repeat 3 times to complete the procedure.

The results thus obtained are shown in Tables 3 and 4. Table 3 shows the results when the surfactant is 1 ppm,
Table 4 shows the results when the surfactant is 10 ppm.

[0035]

[Table 3]

[0036]

[Table 4]

FIGS. 8 to 14 are diagrams showing the relationship between the concentration of mineral oil and the sensor output for each channel in Table 3 and FIGS. 15 to 21 are the channels in Table 4. The horizontal axis represents the concentration of mineral oil in logarithm, and the unit is ppm. The vertical axis represents the output of the lipid membrane sensor and the unit is mV. From these figures, it can be seen that there is a lipid membrane sensor that outputs different values depending on the concentration of mineral oil even in a solution containing a surfactant, and the concentration can be measured. Further, which channel, that is, which lipid membrane responds according to the concentration of the mineral oil, the difference in the sensitivity of each channel, and the like can be known. 4ch (Fig. 11
And FIG. 18)). Also, in the case of 2, 3 and 5 ch, the output pattern with respect to the concentration of mineral oil differs between when the surfactant is 1 ppm and when it is 10 ppm, and when it is 10 ppm, the output does not monotonically increase (Fig. 9 and Fig. 16, Fig. 16). 10 and FIG. 17, and FIG. 12 and FIG. From this, in the case where an alarm is issued when the concentration of the object to be measured exceeds a certain concentration by using the concentration measuring method of the present invention, in order to make the output monotonically increase (or monotonically decrease), the interface is changed depending on the object to be measured. It is necessary to determine the amount of activator added.

FIG. 22 is a diagram showing the result of principal component analysis based on the measured values in Tables 3 and 4 above. All the measured values in Tables 3 and 4 are used for the analysis. From this figure, it can be seen that the change in the mineral oil concentration and the change in the surfactant concentration are obtained in different axial directions. From this, it is understood that the addition of the surfactant does not interfere with the measurement of the concentration of the mineral oil, and the concentration of each of the mineral oil and the surfactant can be measured.

[0039]

EFFECTS OF THE INVENTION According to the present invention, the lipid membrane sensor is used irrespective of the conventional analytical chemistry method, and the measurement can be performed by the lipid membrane sensor. Since the treatment is performed, the concentration of mineral oil and animal and vegetable oils and fats contained in industrial water and the like can be easily measured in a short time, that is, in real time in practical use.

[Brief description of the drawings]

FIG. 1 is a flowchart of a first embodiment of an oil and fat concentration measuring method according to the first invention.

FIG. 2 is a flowchart of a second embodiment of the oil and fat concentration measuring method according to the first invention.

FIG. 3 is a configuration diagram of a first embodiment of an oil and fat concentration measuring device according to the second invention.

FIG. 4 is a configuration diagram of a second embodiment of the oil and fat concentration measuring device according to the second invention.

FIG. 5 is a schematic diagram showing a monomolecular film by an expression method used in a chemical design method.

FIG. 6 is a schematic view of a taste sensor, FIG. 6 (a) is a front view, and FIG. 6 (b) is a sectional view.

FIG. 7 shows a horse mackerel measurement system.

FIG. 8 is a bluff showing the relationship between the concentration of fats and oils and the output of the first channel of the lipid membrane sensor when a surfactant of 1 ppm is added.

FIG. 9 is a bluff showing the relationship between the concentration of fats and oils and the output of the second lipid membrane sensor channel when 1 ppm of a surfactant is added.

FIG. 10 is a bluff showing the relationship between the concentration of fats and oils and the output of the third lipid membrane sensor channel when 1 ppm of a surfactant is added.

FIG. 11 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor 4th channel when 1 ppm of a surfactant is added.

FIG. 12 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor channel 5 when 1 ppm of a surfactant is added.

FIG. 13 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor 6th channel when a surfactant of 1 ppm is added.

FIG. 14 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor channel 7 when a surfactant of 1 ppm is added.

FIG. 15 is a bluff showing the relationship between the concentration of fats and oils and the output of the first lipid membrane sensor channel when 10 ppm of a surfactant is added.

FIG. 16 is a bluff showing the relationship between the concentration of fats and oils and the output of the second lipid membrane sensor channel when 10 ppm of a surfactant is added.

FIG. 17 is a bluff showing the relationship between the concentration of fats and oils and the output of the third lipid membrane sensor channel when 10 ppm of a surfactant is added.

FIG. 18 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor 4th channel when 10 ppm of a surfactant is added.

FIG. 19 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor channel 5 in the case of adding a surfactant of 10 ppm.

FIG. 20 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor 6th channel when 10 ppm of a surfactant is added.

FIG. 21 is a bluff showing the relationship between the concentration of fats and oils and the output of the lipid membrane sensor channel 7 when a surfactant of 10 ppm is added.

FIG. 22 is a diagram showing the results of principal component analysis based on measured values obtained by experiments.

[Explanation of symbols]

 1 Base Material 2 Electrode 3 Lipid Membrane 4 Buffer Layer 5 Lead Wire 10 Basic Configuration of Membrane Potential Measurement System 11 Solution to be Measured 12 Container 13 Taste Sensor Array 14-1 to 14-8 Each Lipid Membrane (Indicated by Black Point) 15 Reference electrode 16 Buffer layer 17-1 to 17-8 Lead wire 18 Lead wire 19-1 to 19-8 Buffer amplifier 20 Analog switch 21 A / D converter 22 Microcomputer 23 XY recorder 24 Ground potential 31, 31 ' Lipid molecule group 32 Membrane member 33 Matrix 41 Lipid membrane sensor 42 Signal processing means 43 Surfactant supply means 44 Stirring means 45 Control means

Claims (2)

[Claims] 1. A method for measuring the concentration of mineral oil and animal and vegetable oils and fats contained in river water, industrial water, etc., which is a measurement target, using a sensor using a lipid membrane, which is included in the measurement target. Mineral oil and animal and vegetable oils and fats are pre-treated to disperse in the object to be measured, and a step of immersing a sensor using a lipid film in a solution to be measured which has become an emulsion by the pre-treatment and measuring its electrical characteristics. Method for measuring fat and oil concentration including. 2. A stirring means for emulsifying a measurement target, a sensor using a lipid membrane for measuring a solution to be measured which has been stirred to form an emulsion, and an output signal of the sensor using the lipid membrane. And a signal processing means for outputting a signal containing information on the concentrations of mineral oil and animal and vegetable oils and fats.