JP2017075809A - Concentration analysis method and concentration analysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement method and a measurement device for performing objective measurement simply and safely without removing liquid to be analyzed from a simplified analysis tool.SOLUTION: A measurement method comprises the steps of: storing a sample liquid into a resin tube; pressing against a portion of the trunk of the resin tube by pressuring means and making constant the optical path length of light passing through a portion of the resin tube in which the sample liquid is stored; letting light of a first wavelength pass through the portion of the resin tube having its optical path length made constant in which the sample liquid is stored and measuring first absorbance of the sample liquid; letting light of a second wavelength pass through the portion of the resin tube having its optical path length made constant in which the sample liquid is stored and measuring second absorbance of the sample liquid; calculating a difference value between the first absorbance and the second absorbance; and comparing the concentration of an analysis object obtained by executing each step using a plurality of standard samples differing in the difference value and the concentration of the analysis object instead of the sample liquid with a calibration curve based on the difference value in each concentration, and finding the concentration of the analysis object in the sample liquid.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a concentration analysis method for measuring the concentration of a substance contained in a liquid to be analyzed by absorbance and an apparatus used for the method.

  As a simple analyzer suitable for quick water quality measurement in the field, the present applicant has developed a simple analyzer (pack test: registered trademark) described in Patent Document 1 and has been highly evaluated. In this pack test, as shown in FIGS. 2 and 3 of this specification, a coloring reagent 11 prepared so as to develop color in response to a substance to be analyzed is sealed in a tube 10 formed of a synthetic resin. This is a simple analysis tool 1. At the time of use, the plug member 12 sandwiched between the ears 15 at the end of the tube is pulled out to form a through hole 13 with the inside, and the tube 10 is crushed with a finger 20 to push out the air 21 therein, and the analysis target liquid 22 is extracted. Inhale like a dropper. The aspirated analysis target liquid 22 chemically reacts with the coloring reagent 11 and develops color. About this coloring state, the concentration of the analyte contained in the analysis target liquid is visually compared with a standard color sequence color-coded for each concentration after a predetermined time, and the numerical value corresponding to the closest color is read. Desired.

  When obtaining the concentration of the sample solution using the above-described simple analysis tool, the standard color array used for the colorimetry is composed of standard colors corresponding to the concentrations selected stepwise. Therefore, it may be recognized that the hue of the sample liquid is between adjacent standard colors (eg, between 0.4 ppm standard color and 1 ppm standard color). In such a case, there is a demand to obtain an objective measurement value when the value in between is used as a measurement value. In addition, there are individual differences in visual colorimetry, and the type and state of the light source at the time of colorimetry may affect the appearance of the color, so we want to obtain measured values regardless of visual colorimetry. There was a request.

  Therefore, the present applicant transfers the liquid to be analyzed developed in the resin tube of the above-described simple analyzer to the cell, and measures the absorbance of the liquid to be analyzed in the cell with a handy type absorptiometer to determine the concentration. Has been developed, manufactured and sold (Non-Patent Document 1).

Japanese Patent No. 4125603

"Digital Pack Test", [online], Kyoritsu Institute of Physical and Chemical Research, Inc. website, [October 13, 2015 search], Internet <URL: http://kyoritsu-lab.co.jp/seihin/list/dpm /index.html>

  However, in the measurement using the apparatus described in Non-Patent Document 1, it takes time since the process of transferring the analysis target liquid from the simple analysis tool to the cell increases. In addition, when the analysis target solution is transferred to the cell, the analysis target solution containing the coloring reagent may spill into the external environment or may adhere to the fingers of the operator.

  The present invention has been made in view of the above-described points, and an object thereof is to provide a measurement method and a measurement apparatus capable of easily and safely performing objective measurement without taking out a liquid to be analyzed from a simple analysis tool. There is to do.

  In order to solve the above problems, the concentration analysis method of the present invention uses a simple analysis tool in which a coloring reagent for an analysis object is enclosed in a flexible resin tube, and the concentration of the analysis object in a sample solution. Is a concentration analysis method for quantitatively determining the absorbance of the resin tube by (a) storing the sample solution in the resin tube, and (b) pressing at least a part of the body of the resin tube with a pressing means. A step of making the optical path length of the light passing through the portion containing the sample liquid constant, and (c) light of the first wavelength in the portion containing the sample liquid in which the optical path length of the resin tube is made constant A step of measuring the first absorbance by letting it pass through; and (d) measuring the second absorbance by passing the light of the second wavelength through the portion in which the sample liquid in which the optical path length of the resin tube is constant is contained. And (e) first absorbance and second absorbance. A difference value obtained in the step (e), and a plurality of standard solutions having different concentrations of the analyte are used instead of the sample solution, and (a) to (f) (E) The step of collating the concentration of the analysis object obtained by performing each step with a calibration curve based on the difference value at each concentration to obtain the concentration of the analysis object in the sample solution.

  When the sample liquid containing the analysis object is accommodated in the resin tube of the simple analysis tool, the coloring reagent enclosed in the interior reacts with the analysis object, and a color reaction occurs. The body portion of the resin tube is pressed by pressing means, and the thickness of the colored sample solution in the resin tube, that is, the optical path length passing through the sample solution together with the resin tube is adjusted to a certain length. By passing different first and second wavelengths through a portion of the resin tube having a constant optical path length and obtaining a difference value between these absorbances, components other than the analysis target, that is, resin tube material and sample It is possible to obtain a value from which a value derived from suspended matter (SS) or the like present in the solution is removed. Since this difference value is proportional to the concentration of the analyte, the absorbance is measured in a similar step for a plurality of standard solutions having a known concentration instead of the above sample solution, and the difference value is obtained. The concentration of the analysis object is obtained by collating with a linear calibration curve obtained from the difference value.

  In the concentration analysis method of the present invention, the first wavelength may be any wavelength within the absorption band range of the analyte, and the second wavelength may be a wavelength outside the absorption band range of the analyte. preferable. The difference value obtained from the first absorbance and the second absorbance reduces the measurement error and improves the accuracy of analysis.

  In addition, the concentration analysis method of the present invention further performs steps (a) to (e) using a plurality of standard solutions having different concentrations of the analyte instead of the sample solution, It is also preferable to provide a step of obtaining a calibration curve based on the difference value at each concentration. By creating a calibration curve for each concentration measurement, the measurement can be performed under the same conditions as the sample solution, so the accuracy of the analysis is improved.

  In addition, the concentration analyzer of the present invention quantifies the concentration of the analyte in the sample solution based on the absorbance using a simple analyzer in which a coloring reagent for the analyte is enclosed in a flexible resin tube. A concentration analyzer, which supports a resin tube containing a sample liquid and a light source that irradiates light having a first wavelength and a second wavelength with respect to the resin tube containing the sample liquid. A tube holder having pressing means for pressing at least a part of the body portion of the resin tube, the first wavelength and the second wavelength so that the optical path length of the light passing through the portion in which the sample liquid is stored is constant. Absorbance measuring means for measuring the first absorbance and the second absorbance when the portion of the resin tube containing the sample liquid is irradiated with light of the wavelength, the first absorbance, and the second absorbance. Calculate the difference value of The difference value calculating means and the difference value are collated with a calibration curve based on a difference value between the first absorbance and the second absorbance obtained by measuring in advance a plurality of standard solutions having different concentrations of the analyte. Concentration calculating means for calculating the concentration of the analysis object.

  When a sample solution containing an analysis object is put into a resin tube of a simple analysis tool, the coloring reagent sealed inside reacts with the analysis object in the sample solution, and a color reaction occurs. When this resin tube is set in the tube holder, the body of the resin tube is pressed by the pressing means provided in the tube holder, and the thickness of the colored sample solution, that is, the optical path length passing through the sample solution together with the resin tube is It is adjusted to a certain length. When the resin tube is irradiated with the first wavelength and the second wavelength from the light source, the first absorbance and the second absorbance are obtained by the absorbance measuring means. Next, the difference value calculation means obtains a difference value of these absorbances. This difference value is derived from components other than the analysis target, that is, from the suspended material (SS) or the like present in the resin tube material or the sample liquid. Is obtained as a value obtained by removing the absorbance. The difference value is collated by a calibration curve based on the difference value between the first absorbance and the second absorbance obtained by measuring in advance with respect to the standard solution of the analysis object and the concentration calculation means to obtain the concentration of the analysis object. It is done.

  Furthermore, in the concentration analyzer of the present invention, the first wavelength is any wavelength within the absorption band range of the analyte, and the second wavelength is a wavelength outside the absorption band range of the analyte. Is also preferable. The difference value between the first absorbance and the second absorbance reduces the error and improves the accuracy of analysis.

  In the concentration analysis method of the present invention, the concentration of the analyte in the sample solution is quantified by the absorbance using a simple analyzer in which a coloring reagent for the analyte is enclosed in a flexible resin tube. A concentration analysis method comprising: (a) a step of storing a sample solution so that an air portion remains in the resin tube; and (b) at least one portion of a portion of the resin tube where the sample solution is stored. A step of pressing at least a part of the portion and the air portion with a pressing means to make the optical path length of the light passing through the resin tube constant, and (c) a sample liquid in which the optical path length of the resin tube is made constant is contained. A step of measuring the absorbance of the sample liquid portion by allowing light to pass through the portion, and measuring the absorbance of the air portion by passing light through the air portion with a constant optical path length of the resin tube; and (d) the sample liquid portion. Absorbance and air part A step of calculating a difference value with respect to the absorbance, and (e) using a plurality of standard solutions having different concentrations of the analyte and the difference value obtained in the step (d) instead of the sample solution (a) to (a) to (D) a step of collating the concentration of the analysis object obtained by performing each step with a calibration curve based on a difference value at each concentration to obtain the concentration of the analysis object in the sample solution.

  The sample solution is stored so that the air portion remains in the resin tube of the simple analyzer. The analyte contained in the stored sample solution reacts with the coloring reagent sealed in the resin tube to cause a color reaction. The body of the resin tube is pressed by pressing means, and the thickness of the resin tube in the portion where the colored sample solution is accommodated and the thickness of the air portion in which nothing is accommodated, that is, the sample solution and the resin tube together The optical path length passing through the air portion is adjusted to a certain length. A value obtained by passing light of the same wavelength through the sample liquid part and the air part with a constant optical path length of the resin tube, and obtaining a difference value of these absorbances, thereby removing values derived from components other than the analyte Can be obtained. Since this difference value is proportional to the concentration of the analyte, the absorbance is measured in a similar step for a plurality of standard solutions having a known concentration instead of the above sample solution, and the difference value is obtained. The concentration of the analysis object is obtained by collating with a linear calibration curve obtained from the difference value.

According to the present invention, it is possible to provide a concentration analysis method and a concentration analyzer having the following excellent effects.
(1) Since it is not necessary to take out a liquid to be analyzed from a simple analyzer when measuring absorbance, analysis can be performed simply, quickly and safely.
(2) The concentration of the analysis object can be obtained as an objective value.

3 is a flowchart schematically showing a concentration analysis method according to the first embodiment of the present invention. It is a figure which shows the example of the simple analyzer used by this invention. It is explanatory drawing which shows the procedure which accommodates an analysis object liquid in the simple analyzer shown in FIG. 1 is a diagram schematically showing a concentration analyzer according to a first embodiment. 4A is a plan view showing the structure of the tube holder of the concentration analyzer shown in FIG. 4, FIG. 5B is a front view, FIG. 5C is a cross-sectional view taken along line AA in FIG. 5A, and FIG. It is a BB sectional view taken on the line. It is a figure which shows schematically the concentration analyzer which concerns on 2nd embodiment. 6A is a plan view showing the structure of the tube holder shown in FIG. 6, FIG. 7B is a front view thereof, FIG. 7C is a cross-sectional view taken along the line CC in FIG. 7A, and FIG. It is line sectional drawing. 5 is a flowchart schematically showing a concentration analysis method according to a second embodiment. It is a figure which shows schematically the concentration analyzer which concerns on 3rd embodiment. 9A is a plan view showing the structure of the tube holder shown in FIG. 9, FIG. 10B is a front view thereof, FIG. 10C is a cross-sectional view taken along the line EE of FIG. 10A, and FIG. It is line sectional drawing. It is a graph which shows the example of the light absorbency in the comparative example 1, and the individual difference of a tube. It is a graph which shows the example of the light absorbency in the comparative example 2, and the individual difference of a tube. 2 is a graph showing the relationship between nitrous acid concentration and absorption spectrum in Example 1. 2 is a graph showing absorbance at each measurement wavelength in Example 1. FIG. 3 is a graph showing a calibration curve obtained from a difference value of each measurement wavelength in Example 1. 4 is a graph showing a relationship between a phosphoric acid concentration and an absorption spectrum in Example 2. 6 is a graph showing a calibration curve obtained from a difference value of each measurement wavelength in Example 2. 6 is a graph showing the relationship between hypochlorous acid concentration and absorption spectrum in Example 3. 10 is a graph showing a calibration curve obtained from a difference value of each measurement wavelength in Example 3.

  The concentration analysis method according to the first embodiment of the present invention will be described below with reference to FIG. As shown in FIG. 1, the concentration analysis method according to the present embodiment is roughly composed of a sample analysis step S1 and a calibration curve creation step S2. Among these, the sample analysis step S1 includes a step S1a for storing the sample liquid in the simple analyzer, a step S1b for pressing the body portion to make the optical path length constant, a step S1c for measuring the first absorbance, and a second step. From the step S1d for measuring the absorbance, the step S1e for calculating the difference value between the first and second absorbances, and the step S1f for comparing the difference value with the calibration curve obtained in the calibration curve creating step S2 to obtain the concentration of the target substance. Composed.

(Sample solution storage)
First, the process S1a for storing the sample solution in the simple analyzer will be described. As shown in FIGS. 2 and 3, the simple analyzer 1 used in the present invention is configured by enclosing a coloring reagent 11 as an analysis object in a flexible resin tube 10. The resin tube 10 of the simple analyzer 1 used in the present invention is preferably formed of a substantially transparent material so that the absorbance of the liquid to be analyzed can be measured together with the simple analyzer 1. In addition, the resin tube 10 is formed of a flexible resin material so that the optical path length when measuring the absorbance by pressing the resin tube 10 from the outside by pressing means to be described later can be set to a certain length. As an example, it is made of polyethylene, nylon, polyethylene terephthalate, or the like. The resin tube 10 according to the present embodiment is provided with a plug member 12 penetrating the inside and outside of the tube embedded in an ear portion 15 at the upper end of the tube, and the plug member 12 is pulled out from the resin tube 10. It is configured to be able to. A through hole 13 is formed in the trace of the plug member 12 being pulled out, and a liquid to be analyzed such as a sample solution or a standard solution can be introduced into the resin tube 10 through the hole 13. The simple analyzer 1 is not particularly limited, but “Pack Test (registered trademark)” manufactured by Kyoritsu Riken Corporation is preferably used.

  When the sample solution 22 is stored in the simple analyzer 1 described above, first, as shown in FIG. 3, the plug member 12 is pulled out with the finger 20 to form the through hole 13. Subsequently, the resin tube 10 is pressed with the finger 20, and the air 21 in the resin tube is discharged from the through hole 13. Next, the portion of the through hole 13 is immersed in the sample solution 22 and the finger 20 is released, and the sample solution 22 is sucked into the simple analyzer 1 like a dropper. After inhaling the sample liquid 22 into the resin tube 10, the sample liquid 22 can be prevented from leaking by being inserted into the through-hole 13 again after being pulled out. When the sample solution 22 is irradiated with light on the body portion of the resin tube 10 and the absorbance is measured together with the simple analyzer 1, the sample solution 22 is accommodated to at least half the capacity of the resin tube 10 so that the irradiation light from the light source passes through. It is preferable to do. When the sample liquid 22 is accommodated in the simple analyzer 1, the coloring reagent 11 and the analysis target in the sample liquid 22 react to generate a color corresponding to the concentration of the analysis target.

(Torso pressing)
Next, the step S1b for pressing the body portion of the resin tube of the simple analyzer and making the optical path length constant will be described. The simple analyzer 1 according to the present invention is composed of a cylindrical resin tube 10 and has a substantially circular cross section. However, since it has flexibility, it easily elastically deforms in the axial thickness direction. Therefore, the shaft thickness of the simple analyzer 1, that is, the optical path length, changes due to individual differences of the simple analyzer 1, the internal pressure of the resin tube 10, and the like. Therefore, as shown in FIG. 5 as an example, in this step S1b, the sample liquid 22 colored by the coloring reagent is obtained by pressing the body portion of the resin tube 10 with the pressing means 50 to make the shaft thickness of the resin tube 10 constant. , That is, the optical path length D of the irradiation light passing through the body of the resin tube is adjusted to a certain length. Specifically, in the concentration analyzer according to the first embodiment shown in FIGS. 4 and 5 as an example, the simple analyzer 1 is inserted into the tube holder 5 provided with the pressing means 50 from the upper side and set. Thus, the optical path length D is adjusted to a fixed length. In the tube holder 5, the pressing means 50 is composed of convex portions formed on portions of the inner wall around the incident light hole 6a and the inner wall around the passing light hole 6b except for the holes, and around the incident light hole 6a. The length of the space between the convex portion formed on the inner wall of the inner wall and the convex portion formed on the inner wall around the passage light hole 6b is configured to be the optical path length D. For this reason, when the simple analyzer 1 is set on the tube holder, the convex pressing means 50 presses the body portion of the resin tube 10 from both sides, and the optical path length D of the resin tube 10 becomes constant. As shown in FIGS. 4 to 5, the direction in which the resin tube 10 is pressed is irradiated with light and pressed in the direction in which the light passes, and the direction in which the light does not pass (direction of the surface facing the passing light). You may press. Further, in the above-described embodiment, the resin tube 10 is pressed so as to be sandwiched between the convex portions formed on the opposing inner walls of the tube holder. However, only the convex portion formed on one inner wall is pressed to press the optical path length. It is also possible to keep D constant.

  Further, in the concentration analyzer according to the second embodiment shown in FIGS. 6 to 7, the resin tube 10 is provided with pressing means 510 such as two pressing walls 510 a that press the body portion so as to sandwich the body portion from the front and rear. It is pressed by fixing it to the tube holder 51. The tube holder 51 is configured such that the length of the space between the two pressing walls 510a becomes the optical path length D. Since the light passing holes 61 (incident light hole 61a and passing light hole 61b) are respectively opened in the two pressing walls 510a in the direction in which light passes, the monochromatic light L2 is the body of the pressed resin tube 10. It is possible to pass through the part with a constant optical path length D. The resin tube 10 is fixed to the tube holder 51 by using four spacers 510b arranged at the four corners of the pressing wall 510a and four screws 510c penetrating therethrough. After the screws 510c penetrating the two pressing walls 510a are loosened and the resin tube 10 is inserted into the space between the two pressing walls 510a, the length D of the spacer 510b is the space between the two pressing walls 510a. The four screws 510c are tightened so that the length becomes. Thereby, the trunk | drum of the resin tube 10 is pinched | interposed and pressed by the two pressing walls 510a, and the axial thickness of the trunk | drum of the resin tube 10 of the direction through which light passes is adjusted uniformly.

  In addition, any configuration can be adopted as the pressing unit as long as the optical path length can be made constant by pressing the body portion of the resin tube of the simple analyzer, and the pressing unit is not limited to the configuration described above.

(First absorbance measurement)
Next, step S1c for measuring the first absorbance and step S1d for measuring the second absorbance will be described. As shown in FIG. 4, after pressing the body part of the resin tube 10 of the simple analyzer 1 with the pressing means 50 to make the optical path length D constant, the optical path length is made constant through the spectroscope 4. The light of the sample liquid 22 accommodated together with the resin tube 10 of the simple analyzer 1 is measured using the photodetector 7. The first wavelength when measuring the first absorbance may be any wavelength within the absorption band range of the analyte, that is, any wavelength within the absorption wavelength range of the analyte, In order to improve the accuracy of the analysis, it is preferable that the absorbance is 95% or more of the absorbance (absorption maximum) at the maximum absorption wavelength of the analyte colored by the coloring reagent, and it is the maximum absorption wavelength. Is more preferable.

(Second absorbance measurement)
Next, step S1d for measuring the second absorbance will be described. Similar to the first absorbance measurement step S1c described above, light of the second wavelength is applied to the resin tube 10 whose optical path length D is constant by pressing the body of the resin tube 10 of the simple analyzer 1 with the pressing means 50. , And the absorbance of the sample liquid 22 accommodated together with the resin tube 10 of the simple analyzer 1 is measured using the photodetector 7. The second wavelength for measuring the second absorbance may be any wavelength as long as a differential value between the first and second absorbances described later can be obtained, but in order to increase the accuracy of the analysis. , Preferably a wavelength other than the maximum absorption wavelength of the analyte colored by the coloring reagent, and a wavelength at which an absorbance less than the absorbance at the bottom (absorption edge) of the absorption band having the absorption maximum is obtained, More preferably, the absorption wavelength.

(Difference measurement)
Next, step S1e for calculating a difference value from the first and second absorbances will be described. In this step, a difference value between the first absorbance and the second absorbance obtained in the above-described step is calculated. As a result, a value obtained by subtracting the absorbance derived from components other than the analysis target, that is, the turbidity of the resin tube material itself or the suspended matter (SS) present in the sample liquid is obtained, and the analysis accuracy is improved.

(Calibration curve verification)
Next, step S1f for obtaining the target substance concentration by comparing the difference value with the calibration curve obtained in the calibration curve creation step S2 will be described. In this step, the concentration of the substance to be analyzed in the sample liquid 22 is obtained by comparing the difference value obtained in the difference value measurement step S1e with a calibration curve described later.

(Calibration curve creation process)
The calibration curve creation step S2 will be described. The calibration curve creation step S2 includes a step S2a for storing the standard solution in the simple analyzer, a step S2b for pressing the body part to make the optical path length constant, a step S2c for measuring the first absorbance, and the second absorbance. It comprises a step S2d for measuring, a step S2e for calculating a difference value between the first and second absorbances, and a calibration curve creating step S2f based on the difference value of the standard solution. Among these, the step S2a for accommodating the standard solution in the simple analyzer, the step S2b for pressing the body part to make the optical path length constant, the step S2c for measuring the first absorbance, and the step S2d for measuring the second absorbance. The step S2e for calculating the difference value between the first and second absorbances is performed by replacing the sample solution 22 in the sample analysis step S1 with a plurality of standard solutions having different concentrations. The first absorbance and the second absorbance are measured at the same wavelength as the first wavelength and the second wavelength respectively employed in the sample analysis step S1, and the difference value of the absorbance for the standard solution of the analyte with a known concentration. Is required. In the calibration curve creation step S2f, a calibration curve is obtained by creating a relationship line between the difference value obtained for a plurality of standard solutions having different concentrations and the concentration of the analyte.

  Next, the concentration analyzer 100 according to the first embodiment will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, the concentration analyzer 100 according to the present embodiment includes a light source 3 capable of irradiating light of different wavelengths, a spectroscope 4 that splits light L1 from the light source 3 into monochromatic light L2, and a resin tube. 10 is a calibration curve obtained by calculating a difference value of absorbance at different wavelengths and measuring the difference value in advance with respect to a standard solution of the analysis target. And a calculation unit 8 for calculating the concentration of the analysis object and a memory 9 for storing calibration curve data obtained by measurement in advance.

  Although the light source 3 should just be what can irradiate the light of several arbitrary wavelengths, an LED light source is used suitably from a viewpoint which can make apparatus itself compact and can also reduce power consumption. Among them, an LED having excellent color rendering properties is preferably used from the viewpoint that the spectral distribution in the visible light region is generally high and stable. The light L1 emitted from the light source 3 is split by the spectroscope 4 into predetermined monochromatic light L2, that is, light having the first wavelength or light having the second wavelength. As shown in FIG. 4, the light L2 irradiated from the light source 3 and split by the spectroscope 4 passes through the body portion of the resin tube 10 of the simple analyzer 1 housed in the tube holder 5, and absorbs light. 7, the intensity of the passing light L3 is measured.

  The tube holder 5 includes a pressing unit 50 that supports the simple analyzer 1 and presses the body of the resin tube 10 so that the monochromatic light L2 from the spectroscope 4 passes through a predetermined position of the resin tube 10. It is configured. As shown in FIG. 5, the tube holder 5 of the present embodiment is formed as a quadrangular column having an open top surface, and has a substantially circular light passage hole 6 on two opposing surfaces of the four column side surfaces, that is, a single color. An incident light hole 6a through which the light L2 enters and a passing light hole 6b through which the light that has passed through the resin tube 10 passes are respectively arranged. The tube holder 5 includes a pressing unit 50 that presses the body of the resin tube of the simple analyzer 1. The tube holder 5 is flexible by pressing the body of the resin tube 10 with the pressing unit 50. The axial thickness of the resin tube 10, that is, the optical path length D can be made constant.

  In the present embodiment, the pressing means 50 is configured as a convex portion formed inside the wall including the incident light hole 6a and the passing light hole 6b. More specifically, as shown in FIGS. 4 and 5, the pressing means 50 is formed on the inner wall around the incident light hole 6a and the inner wall around the passing light hole 6b of the tube holder 5 except for the holes. The width between the protrusion formed on the inner wall around the incident light hole 6a and the protrusion formed on the inner wall around the passing light hole 6b becomes the optical path length D. It is configured as follows. The height of the convex portion of the pressing means 50 is preferably constant for each wall surface in order to reliably press the resin tube 10 and make the optical path length D constant. However, as shown in the present embodiment, the optical path length is constant. In a range that does not affect D, for example, only the upper portion of the pressing means 50 is formed into a valley-shaped taper shape to form a guide surface, and the simple analyzer 1 is easily inserted into the tube holder 5. It is also possible. As shown in FIG. 5, when the simple analyzer 1 is inserted into the tube holder, the resin tube 10 is pressed from both sides by the pressing means 50, and the shaft thickness of the body portion of the resin tube 10 is as shown in FIG. In side view, it becomes as thin as the optical path length D. In this way, by pressing the body portion of the resin tube 10 of the simple analyzer 1 with the pressing means 50, the optical path length D of the resin tube becomes constant, and the influence of individual differences of the simple analyzer 1 is reduced. Even if the simple analyzer 1 is used, the absorbance can be measured with the same optical path length D. At this time, as shown in FIG. 5D, in the front view, the shaft thickness of the resin tube 10 is enlarged because it is pressed by the pressing means 50, and is approximately at the central portion of the enlarged shaft portion. Light enters and passes. As described above, when the axial thickness in the light incident direction is increased by pressing the resin tube 10, the surface of the originally curved resin tube 10 becomes substantially planar at the incident portion and the passing portion. Thus, since reflection and scattering of incident and passing light are reduced, the absorbance can be measured with higher accuracy.

  As shown in FIG. 4, the light L3 that has passed through the body portion of the resin tube 10 via the incident light hole 6a of the tube holder 5 reaches the absorbance measurement means 7 via the other passing light hole 6b. The absorbance measurement means 7 is mainly a photodetector, and the absorbance is obtained by measuring the light intensity of the reached light L3 with the photodetector 7.

  When the absorbance of the light L3 that has passed through the body of the resin tube 10 at the first wavelength and the second wavelength is measured by the photodetector 7 with respect to the sample liquid 22 accommodated in the simple analyzer 1, these are detected. The difference value of absorbance is calculated by the calculation means 8 connected to the photodetector 7. Next, this difference value is subsequently collated by the calculation means 8 with a calibration curve obtained by measuring in advance the standard solution of the analysis object, and the concentration of the analysis object is obtained. A memory 9 is connected to the calculation means 8, and calibration curve data can be stored in this memory in addition to the processing data in the calculation means 8.

  Next, the concentration analyzer 200 according to the second embodiment will be described with reference to FIGS. 6 and 7. The concentration analyzer 200 according to the second embodiment of the present invention has the same configuration as that of the device 100 according to the first embodiment except that the configuration of the tube holder 51 is different. In the present embodiment, the same configuration as the apparatus 100 according to the first embodiment will be described using the same reference numerals. That is, as shown in FIG. 6, the concentration analyzer 200 according to this embodiment includes a light source 3 that can emit light of different wavelengths, a spectroscope 4 that splits light L1 from the light source 3 into monochromatic light L2, and The tube holder 51 that supports the resin tube 10, the absorbance measurement means 7 that measures the absorbance, and the difference value of the absorbance at different wavelengths is calculated, and this difference value is obtained by measuring the standard solution of the analyte in advance. Computation means 8 for computing the concentration of the analysis object in comparison with the calibration curve, and a memory 9 for storing calibration curve data obtained by measurement in advance are roughly provided.

  The tube holder 51 includes pressing means 510 that presses the body of the resin tube 10 while supporting the simple analyzer 1, and the monochromatic light L <b> 2 from the spectroscope 4 passes through the pressed portion of the resin tube 10. It is configured as follows. As shown in FIGS. 6 and 7, the tube holder 51 of the present embodiment is roughly configured from a structure in which two pressing walls 510 a are vertically opposed to each other on a base base 511 arranged horizontally. Yes. In the present embodiment, one pressing wall 510a of the two pressing walls 510a and the base base 511 are fixed. Cylindrical spacers 510b are arranged at the four corners between the two pressing walls 510a, and the length of the spacer 510b is configured to be the distance D of the space sandwiched between the two pressing walls 510a. Yes. The spacer 510b is formed in a hollow shape, and is fixed in an adjustable manner by screw holes provided at four corners of the pressing wall 510a and screws 510c penetrating through the spacer 510b. In this way, the pressing means 510 is configured by the screw 510c attached through the first pressing wall 510a, the spacer 510b, and the second pressing wall 510a. By pressing the body portion of the resin tube 10 with these pressing means 510, the shaft thickness of the resin tube 10 having flexibility, that is, the optical path length D can be made constant.

  In the present embodiment, as shown in FIG. 7, the two pressing walls 510a constituting the pressing means 510 have an elongated rectangular light passage hole 61, that is, an incident light hole 61a into which the monochromatic light L2 enters and a resin. Passing light holes 61b through which light that has passed through the tube 10 passes are formed. Therefore, by pressing the resin tube 10 to some extent by the pressing wall 510a provided with the incident light hole 61a and the pressing wall 510a provided with the passing light hole 61b, an optical path from the incident light hole 61a to the passing light hole 61b. The length D can be adjusted. The distance D of the space between the two pressing walls 510a of the pressing means 510, that is, the length of the spacer 510b was pressed to such an extent that differences in shaft thickness due to individual differences in the resin tube 10 and internal pressure do not substantially occur. The axial thickness of the resin tube 10 at that time may be sufficient. Specifically, although depending on the material and physical properties of the resin tube 10, as an example, the length D of the spacer 510b is preferably 85% or less of the shaft thickness of the resin tube, and 75% or less. More preferred is 65% or less. In the present embodiment, the axial thickness of the resin tube 10 is 10 to 12 mm, and the length D of the spacer 510b is designed to be 7 mm. Setting and pressing of the resin tube 10 to the tube holder 51 of the present embodiment are performed as follows. After the screws 510c and nuts passing through the two pressing walls 510a and the spacer 510b are loosened and the resin tube 10 is inserted into the space between the two pressing walls 510a, the length of the spacer 510b is two pressing walls 510a. Tighten the four screws 510c so that the length D of the space between them is the same. Thus, the body portion of the resin tube 10 is sandwiched and pressed by the two pressing walls 510a, and the axial thickness of the body portion of the resin tube 10 in the direction in which light passes is adjusted to a certain length D. Thus, by pressing the body of the resin tube 10 of the simple analyzer 1 with the pressing means 510, the optical path length D of the resin tube becomes constant, and the influence of individual differences of the simple analyzer 1 is reduced. Even if the simple analyzer 1 is used, the absorbance can be measured with the same optical path length D. At this time, as shown in FIG. 7D, in the front view, the shaft thickness of the resin tube 10 is enlarged because the resin tube 10 is pressed by the pressing means 510, and at the substantially central portion of the expanded shaft portion. Light enters and passes. As described above, when the axial thickness in the light incident direction is increased by pressing the resin tube 10, the surface of the originally curved resin tube 10 becomes substantially planar at the incident portion and the passing portion. Thus, since the reflection and scattering of incident and passing light are reduced, the absorbance is measured with higher accuracy. In addition, when pressing the resin tube 10 with the pressing means 510 in this way, it is also preferable to provide a buffer member on the inner surface of the pressing wall 510a in order to avoid damage to the outer wall of the resin tube and affecting the absorbance. . Although it does not specifically limit as a buffer member, Sheet-like rubber | gum, an elastomer, a gel-like material, or a resin foam material etc. are mentioned.

  The other configurations of the light source 3, the spectroscope 4, the absorbance measuring means 7, the calculating means 8 and the memory 9 and the other usage methods are the same as those of the device 100 according to the first embodiment described above. The effect is also the same. Further, the configuration and usage method of the simple analyzer 1 used in the simple analyzer 200 are the same as those in the method according to the first embodiment described above, and the functions and effects thereof are also the same.

  Next, a concentration analysis method according to the second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 8, the concentration analysis method according to the present embodiment is roughly configured from a sample analysis step S10 and a calibration curve creation step S20. Among these, the sample analysis step S10 includes a step S10a for storing the sample solution in the simple analysis tool, a step S10b for pressing the body portion to make the optical path length constant, a step S10c for measuring the absorbance of the sample solution and the air portion, A step S10d for calculating a difference value between the absorbance of the sample liquid and the air portion, and a step S10e for comparing the difference value with the calibration curve obtained in the calibration curve creating step S20 to obtain the target substance concentration.

(Sample solution storage)
First, step S10a for storing the sample solution in the simple analysis tool will be described. The configuration, function, and method of use of the simple analyzer used in the present invention are the same as those of the simple analyzer 1 used in the concentration analysis method according to the first embodiment described above. In the present embodiment, when the sample solution 22 is stored in the simple analyzer 1, the sample solution 22 is stored so that the air portion remains in the resin tube 10 (see the resin tube 10 in FIG. 9). This is because, as will be described later, the two absorbances of the absorbance of the sample solution 22 and the absorbance of the air portion 21 can be measured almost simultaneously using one simple analyzer 1. It is preferable that the amount of the sample liquid 22 is not more than half of the capacity of the resin tube 10.

(Torso pressing)
Next, step S10b for pressing the body portion of the resin tube of the simple analyzer and making the optical path length constant will be described. In this embodiment, as shown in FIG. 9 and FIG. 10 as an example, the pressing portion 520 presses the body portion of the resin tube 10 where the sample solution is stored and the body portion of the air portion. Thereby, the axial thickness of the resin tube 10 of the pressed part is made constant, and the optical path length D of the irradiation light passing therethrough is adjusted to a constant length. Specifically, in the concentration analyzer according to the third embodiment shown in FIG. 9 to FIG. 10, the resin tube 10 has a pressing means 520 such as two pressing walls 520 a that press the resin tube 10 while sandwiching the body portion from the front and rear. It is pressed by fixing to a tube holder 52 provided with. The tube holder 52 is configured such that the length of the space between the two pressing walls 520a becomes the optical path length D. In the two pressing walls 520a, light passage holes (incident light hole 62a and passage light hole 62b) are formed in the direction in which light passes. These light passage holes 62 are formed as rectangular holes extending vertically along the long axis direction (vertical direction in the figure) of the resin tube supported and fixed to the pressing means 52. Therefore, the amount of the sample liquid accommodated in the resin tube 10 in the above-described sample liquid accommodation step S10a is such that when the simple analyzer 1 is pressed by the pressing means 52 as shown in FIGS. It is preferable to adjust so that the liquid level of the sample liquid 22 can be confirmed from the passage hole 62, the sample liquid 22 accommodated in the lower part of the light passage hole 62 is located, More preferably, the amount of the sample solution 22 is adjusted so that 21 is located. Thereby, two absorbances, the absorbance of the sample liquid 22 portion of the resin tube 10 and the absorbance of the air portion 21, can be measured together via the light passage hole 62. In the present embodiment, the light passage hole 62 has a configuration in which one longitudinal wall is provided in one pressing wall 520a. However, the light passage hole 62 is individually provided for the sample liquid 22 portion and the air portion 21 of the resin tube 10. It is good also as a structure provided with two or more holes in one press wall 520a so that light can pass through, and it is not limited to the structure mentioned above.

  As shown in FIGS. 9 and 10, the pressing means 520 adjusts the axial thickness of the portion of the resin tube 10 in which the sample liquid 22 is stored and the air portion 21 to a certain length, so that the monochromatic light L2 is obtained. And L20 can pass through these portions with a constant optical path length D, respectively. The resin tube 10 is fixed to the tube holder 52 by using four spacers 520b arranged at the four corners of the pressing wall 520a and four screws 520c penetrating therethrough. After the screws 520c and nuts passing through the two pressing walls 520a are loosened and the resin tube 10 is inserted into the space D between the two pressing walls 520a, the length of the spacer 520b is between the two pressing walls 520a. The four screws 520c are tightened so as to be the length of the space. Thereby, the trunk | drum of the resin tube 10 is pinched | interposed and pressed by the two pressing walls 520a, and the axial thickness of the trunk | drum of the resin tube 10 of the direction through which light passes is adjusted uniformly. In addition, any configuration can be adopted as the pressing unit as long as the optical path length can be made constant by pressing the body portion of the resin tube of the simple analyzer, and the pressing unit is not limited to the configuration described above.

(Absorbance measurement of sample liquid and air part)
Next, step S10c for measuring the absorbance of the sample solution and the air portion will be described. As shown in FIG. 9, the optical path length D is made constant by pressing the portion of the simple analyzer 1 in which the sample liquid 22 is stored and the body portion of the resin tube 10 of the air portion 21 with the pressing means 520. Next, the sample liquid 22 and the air 21 having a constant optical path length are irradiated with light L2 and L20 having a predetermined wavelength through the incident light holes 62a, respectively, and the resin tube 10 of the simple analyzer 1 is accommodated together. The absorbances of the sample liquid 22 and the air 21 are measured using the photodetectors 7 and 70, respectively. The wavelength for measuring these absorbances may be any wavelength within the absorption band range of the analyte, i.e., any wavelength within the absorption wavelength range of the analyte. In order to increase the absorbance, it is preferable that the absorbance is 95% or more of the absorbance (absorption maximum) at the maximum absorption wavelength of the analyte colored by the coloring reagent, and more preferably the maximum absorption wavelength.

(Difference measurement)
Next, step S10d for calculating the difference value of absorbance will be described. In this step, a difference value is calculated from the absorbance of the sample liquid 22 portion and the absorbance of the air 21 portion obtained in the above-described step. As a result, a value obtained by subtracting the absorbance derived from components other than the analysis target, that is, the turbidity of the resin tube material itself or the suspended matter (SS) present in the sample liquid is obtained, and the analysis accuracy is improved.

(Calibration curve verification)
Next, step S10e for obtaining the target substance concentration by comparing the difference value with the calibration curve obtained in the calibration curve creation step S20 will be described. In this step, the concentration of the analysis target substance in the sample solution 22 is obtained by comparing the difference value obtained in the difference value measurement step S10d with a calibration curve described later.

(Calibration curve creation process)
The calibration curve creation step S20 will be described. The calibration curve creating step S20 includes a step S20a for storing the standard solution in the simple analyzer, a step S20b for pressing the body part to make the optical path length constant, a step S20c for measuring the absorbance of the standard solution and the air portion, and the standard solution. It consists of a step S20d for calculating the difference between the absorbance of the part and the air part and a calibration curve creating step S20e based on the difference value of the standard solution. Among these, the step S20a for storing the standard solution in the simple analyzer, the step S20b for pressing the body portion to make the optical path length constant, the step S20c for measuring the absorbance of the standard solution and the air portion, the standard solution portion and the air portion The step S20d of calculating the difference value of the absorbance is performed by replacing the sample solution 22 in the sample analysis step S10 with a plurality of standard solutions having different concentrations. The absorbances of the standard solution and the air portion are measured at the same wavelength as the absorbance measurement wavelength employed in the sample analysis step S10, and a difference value in absorbance is obtained for the standard solution of the analyte with a known concentration. In the calibration curve creation step S20e, a calibration curve is obtained by creating a relationship line between the difference value obtained for a plurality of standard solutions having different concentrations and the concentration of the analyte.

  Next, the concentration analyzer 300 according to the third embodiment will be described with reference to FIGS. 9 and 10. In the concentration analyzer 300 according to the third embodiment of the present invention, the configuration of the light passage hole 62 of the tube holder 52 and the point that the monochromatic lights L2 and L20 incident on the tube holder 52 have a double beam configuration and the photodetector 7 are used. , 70 has the same configuration as that of the apparatus 200 according to the second embodiment except that the two are provided. In addition, in this embodiment, the same structure as the apparatus which concerns on 1st and 2nd embodiment is demonstrated using the same referential mark. That is, as shown in FIG. 9, the concentration analyzer 300 according to this embodiment includes a light source 3, a spectroscope 4 that splits the light L1 from the light source 3 into the monochromatic light L2, and a part of the monochromatic light L2 as L20. Mirrors M1 and M2 that are branched to each other, a tube holder 52 that supports the resin tube 10, an absorbance measuring means 7 that measures the absorbance of the sample liquid 22, an absorbance measuring means 70 that measures the absorbance of the air 21 portion, and a sample liquid A calculating means for calculating a concentration value of the analyte by calculating a difference value between the absorbance of 20 and the absorbance of the air 21 portion, and comparing the difference value with a calibration curve obtained by measuring the standard solution of the analyte in advance. 8 and a memory 9 for storing calibration curve data obtained by measurement in advance.

  The tube holder 52 includes a pressing means 520 that presses the body of the resin tube 10 while supporting the simple analyzer 1, and the portion where the monochromatic light L <b> 2 and L <b> 20 from the spectroscope 4 are pressed on the resin tube 10. It is configured to pass. As shown in FIGS. 9 and 10, the tube holder 52 of the present embodiment is roughly configured from a structure in which two pressing walls 520 a are vertically opposed to each other on a horizontally arranged base table 521. Yes. Cylindrical spacers 520b are arranged at the four corners between the two pressing walls 520a, and the length of the spacer 520b is configured to be the distance D of the space sandwiched between the two pressing walls 520a. Yes. The spacer 520b is formed in a hollow shape, and is fixed in an adjustable manner by screw holes 520c provided at four corners of the pressing wall 520a and screws 520c penetrating the inside of the spacer 520b. Thus, the pressing means 520 is constituted by the first pressing wall 520a, the spacer 520b, and the screw 520c attached through the second pressing wall 520a. By pressing the body portion of the resin tube 10 with these pressing means 520, the axial thickness of the body portion of the resin tube 10 having flexibility and the body portion of the air portion, that is, the optical path length D Can be made constant.

  In the present embodiment, as shown in FIG. 10, the two pressing walls 520 a constituting the pressing means 520 have a vertically long rectangular shape extending in the vertical direction (the long axis direction of the simple analyzer 1 supported and fixed). A light passing hole 62, that is, an incident light hole 62a through which the monochromatic lights L2 and L20 enter, and a passing light hole 61b through which the light L3 and L30 having passed through the resin tube 10 pass are formed. Therefore, by pressing the resin tube 10 to some extent by the pressing wall 520a provided with the incident light hole 62a and the pressing wall 520a provided with the passing light hole 62b, an optical path from the incident light hole 62a to the passing light hole 62b. The length D can be adjusted. In the present embodiment, the incident light hole 62a and the passing light hole 62b are formed in a rectangular shape that is long in the vertical direction. Therefore, the monochromatic light L2 is supplied to the sample liquid 22 portion accommodated in the resin tube 10 and the monochromatic light L20 to the air 21 portion in which nothing is accommodated in the resin tube 10 through one incident light hole 62a. The light L3 that has passed through the sample liquid 22 part and the light L30 that has passed through the air part can be passed through one passing light hole 62b. Note that the configuration of the light passage hole 62 is not limited to the configuration including one in each pressing wall 520a, and each pressing wall 520a includes a plurality of holes, and allows the sample liquid 22 portion and the air 21 portion to individually transmit light. It is good also as a structure and is not limited to the structure of this embodiment.

Setting and pressing of the resin tube 10 to the tube holder 52 of the present embodiment are performed as follows. After the screws 520c passing through the two pressing walls 520a and the spacer 520b are loosened and the resin tube 10 is inserted into the space between the two pressing walls 520a, the length of the spacer 520b is between the two pressing walls 520a. The four screws 520c are tightened so that the length of the space becomes D. As a result, the body portion of the resin tube 10 is sandwiched and pressed by the two pressing walls 520a, and the axial thickness of the body portion of the resin tube 10 in the direction in which light passes is adjusted to a certain length D. At this time, the two absorbances, the absorbance of the sample liquid 22 portion of the resin tube 10 and the absorbance of the air portion 21, can be measured together through the light passage hole 62 provided in the pressing wall 520a. As shown in FIG. 4, it is preferable to adjust so that the liquid level of the sample liquid 22 can be confirmed from the light passage hole 62, and the liquid level of the sample liquid 22 accommodated in the vicinity of the approximate center of the light passage hole 62 is located. More preferably, the amount of the sample liquid 22 is adjusted. Thus, by pressing the body of the resin tube 10 of the simple analyzer 1 with the pressing means 520, the optical path length D of the absorbance measurement portion of the resin tube 10 becomes constant, and the influence of individual differences of the simple analyzer 1 The absorbance can be measured with the same optical path length D regardless of which simple analytical tool 1 is used. In addition, the description about the other structure of the tube holder 52, its function, and the usage method is the same as that of the tube holder 51 of the apparatus 200 which concerns on 2nd embodiment mentioned above.

  As shown in FIG. 9, the lights L3 and L30 that have passed through the body portion of the resin tube 10 through the incident light hole 62a of the tube holder 52 reach the absorbance measurement means 7 through the other passing light hole 62b. . The absorbance measurement means 7 is mainly a photodetector, and the absorbance of the sample liquid 22 is obtained by measuring the light intensity of the reached light L3 with the photodetector 7, and the light intensity of the reached light L30 is detected by light detection. By measuring with the vessel 70, the absorbance of the air 21 portion is obtained.

  When the absorbances of the sample liquid 22 portion accommodated in the simple analyzer 1 and the air 21 portion in which nothing is accommodated are measured by the photodetectors 7 and 70, the difference value between these absorbances is determined by the photodetector 7. It is calculated by the calculation means 8 connected to. Next, this difference value is subsequently collated by the calculation means 8 with a calibration curve obtained by measuring in advance the standard solution of the analysis object, and the concentration of the analysis object is obtained. A memory 9 is connected to the calculation means 8, and calibration curve data can be stored in this memory in addition to the processing data in the calculation means 8.

  Further, the configuration of the light source 3 and the spectroscope 4 and other explanations about the method of use are the same as in the case of the apparatus according to the first embodiment described above, and the functions and effects thereof are also the same. Further, the configuration and method of use of the simple analyzer 1 used in the simple analyzer 300 are the same as those in the method according to the first embodiment described above, and the functions and effects thereof are also the same.

  Hereinafter, the present invention will be described in detail with reference to examples.

[Comparative Example 1]
1. Examination of absorption spectroscopic method using simple analytical instrument as it is 1
In the apparatus 200 according to the second embodiment of the present invention shown in FIG. 6 and FIG. 7, the following test was performed in a state where the pressing means 510 of the tube holder 51 was not functioned. The absorbance was measured in a state where the screw 510c of the pressing means 510 of the tube holder 51 was loosened and the distance D between the two pressing walls 510a was 13 mm. Six simple analytical tools 1 (Kyoritsu Riken Co., Ltd. product, pack test) were prepared. After removing the coloring reagent from the simple analyzer 1, 1.5 mL of distilled water is accommodated in the resin tube 10, set in the tube holder 51 adjusted as described above, and the resin of the simple analyzer at a measurement wavelength of 532 nm. The absorbance of the water contained in the tube 10 was measured. The baseline measurement was performed on the tube holder 51 without setting the simple analyzer 1, that is, on the empty tube holder 51. The shaft thickness of the body part of the resin tube of the simple analyzer used for the test was in the range of 10 to 12 mm, and none of the body parts of the resin tube were pressed. The measurement results are shown in FIG. The absorbance at a measurement wavelength of 532 nm was in the range of 0.520 to 0.935, the average value was 0.694, and the standard deviation was 0.159. Thus, it was found that when the absorbance was measured as it was with a simple analyzer, the absorbance obtained was highly variable.

[Comparative Example 2]
2. Study of absorption spectrophotometry using simple analytical instrument as it is 2
In the apparatus 200 which concerns on 2nd embodiment of this invention shown in FIG.6 and FIG.7, the test was done in the state which made the press means 510 of the tube holder 51 function. The absorbance was measured in a state where the screw 510c of the pressing means 510 of the tube holder 51 was tightened and the distance D between the two pressing walls 510a was 7 mm. Six simple analytical tools 1 (Kyoritsu Riken Co., Ltd. product, pack test) were prepared. After removing the coloring reagent from the simple analyzer 1, 1.5 mL of distilled water is accommodated in the resin tube 10, set in the tube holder 51 adjusted as described above, and the resin of the simple analyzer at a measurement wavelength of 532 nm. The absorbance of the water contained in the tube 10 was measured. The baseline measurement was performed on the tube holder 51 without setting the simple analyzer 1, that is, on the empty tube holder 51. The shaft thickness of the body part of the resin tube of the simple analyzer used for the test was in the range of 10 to 12 mm, and the body part of the resin tube was in a pressed state. The measurement results are shown in FIG. The absorbance at a measurement wavelength of 532 nm was in the range of 0.569 to 0.736, the average value was 0.633, and the standard deviation was 0.062. Compared with the result of Comparative Example 1, since the variation ratio decreased, it was found that adjustment of the optical path length by the pressing means improves the accuracy of analysis. Moreover, since the light absorbency measured by the present Example is a light absorbency mainly derived from the resin tube which consists of polyethylene materials, it turned out that there exists the dispersion | variation resulting from the individual difference of a polyethylene tube.

3. Absorption analysis method using a simple analyzer for measuring nitrous acid as it is In the apparatus 200 according to the second embodiment of the present invention shown in FIGS. 6 and 7, the following test is performed with the pressing means 510 of the tube holder 51 functioning. went. The absorbance was measured in a state where the screw 510c of the pressing means 510 of the tube holder 51 was tightened and the distance D between the two pressing walls 510a was 7 mm. A standard solution having a nitrous acid concentration of 1 ppm was prepared. Three simple analyzers 1 (Kyoritsu Riken Co., Ltd. product, Pack Test WAK-NO ₂ ) were prepared, 1.5 mL of this standard solution was sucked in, and mixed well with the coloring reagent. The simple analyzer 1 was set one by one in the tube holder 51 adjusted as described above, and the absorbance was measured. The measurement wavelengths were 532 nm, 650 nm, and 700 nm. Absorbance was measured in the same manner for standard solutions having nitrous acid concentrations of 0.5 ppm, 0.1 ppm, and 0 ppm. The baseline measurement was performed on the tube holder 51 without setting the simple analyzer 1, that is, on the empty tube holder 51. The shaft thickness of the body part of the resin tube of the simple analyzer used for the test was in the range of 10 to 12 mm, and the body part of the resin tube was in a pressed state. FIG. 13 shows an absorption spectrum in the entire wavelength range of a simple analyzer containing 1.5 mL of a standard solution of nitrous acid of each concentration. According to this absorption spectrum, the wavelength range of the absorption band of nitrous acid is about 450 to 620 nm, and the maximum absorption wavelength is about 520 to 550 nm.

  Table 3 below shows the difference in absorbance at different wavelengths from the measured absorbance at each measurement wavelength. FIG. 14 shows a calibration curve based on the absorbance at each measurement wavelength and the concentration of the standard solution, and FIG. 15 shows a calibration curve based on the difference value and the concentration of the standard solution.

  Based on the absorbance values at each measurement wavelength in Table 3 and the results shown in FIG. 14, the data indicating the relationship between the absorbance at each measurement wavelength and the concentration of the standard solution was examined. As a result, the variation in absorbance was reduced by adjusting the optical path length with the pressing means. However, as shown in FIG. 14, it was found that the relationship line based on the absorbance and the concentration of the standard solution was not linear, and could not be used as a calibration curve. On the other hand, regarding the difference values obtained from the absorbance values at different measurement wavelengths, as shown in Table 3 and FIG. 15, the difference value has a smaller variation, and the relationship line based on the absorbance and the concentration of the standard solution. Was found to be linear. This difference value is a value obtained by subtracting the absorbance at a wavelength outside the absorption wavelength range from the absorbance at the maximum absorption wavelength of the nitrite ion that is the analysis object. It is considered that the absorbance at a wavelength outside the absorption wavelength range substantially indicates light absorption by the resin tube material itself of the simple analyzer. Therefore, by subtracting the absorbance at a wavelength outside the absorption wavelength range, the dispersion of the resin tube material is eliminated, and only the absorption due to the colored state of the nitrous acid solution contained in the simple analyzer is accurate. It was found to be measured well.

4). Absorption analysis method using a simple analytical instrument for measuring phosphoric acid as it is. The apparatus 200 used in Example 1 was used, and the following test was performed with the pressing means 510 of the tube holder 51 functioning. The screw 510c of the pressing means 510 of the tube holder 51 was tightened, and the absorbance of phosphoric acid was measured in a state where the distance D between the two pressing walls 510a was 7 mm. A standard solution having a phosphoric acid concentration of 5 ppm was prepared. One simple analytical instrument 1 (Kyoritsu Riken Laboratories Co., Ltd. product, Pack Test WAK-PO ₄ ) was prepared, and 1.5 mL each of this standard solution was sucked in and mixed well with the coloring reagent. The simple analyzer 1 was set in the tube holder 51 adjusted as described above, and the absorbance was measured. The measurement wavelengths were 500 nm and 710 nm. Absorbance was measured in the same manner for standard solutions having phosphoric acid concentrations of 1 ppm, 0.5 ppm, 0.1 ppm and 0 ppm. The baseline measurement was performed on the tube holder 51 without setting the simple analyzer 1, that is, on the empty tube holder 51. The shaft thickness of the body part of the resin tube of the simple analyzer used for the test was in the range of 10 to 12 mm, and the body part of the resin tube was in a pressed state. FIG. 16 shows an absorption spectrum in the entire wavelength range of a simple analyzer containing 1.5 mL of a standard solution of phosphoric acid at each concentration. According to this absorption spectrum, the wavelength range of the phosphoric acid absorption band is approximately 500 to 800 nm, and the maximum absorption wavelength is approximately 650 to 730 nm.

  Table 4 below shows the difference in absorbance at different wavelengths from the measured absorbance at each measurement wavelength. Further, FIG. 17 shows a calibration curve based on each measurement wavelength or its difference value and the concentration of the standard solution.

  From the absorbance values at each measurement wavelength in Table 4 and the results in FIG. 17, it was found that the relationship line based on the difference value obtained from the absorbance values at different measurement wavelengths and the concentration of the standard solution was linear. This difference value is a value obtained by subtracting the absorbance at a wavelength outside the absorption wavelength range (500 nm) from the absorbance at a wavelength near the maximum absorption wavelength (710 nm) of the phosphate ion that is the analysis object. It is considered that the absorbance at a wavelength outside the absorption wavelength range substantially indicates light absorption by the resin tube material itself of the simple analyzer. Therefore, by subtracting the absorbance at wavelengths outside the absorption wavelength range, the dispersion of the resin tube material is eliminated, and only the absorption due to the color development state of the phosphoric acid solution contained in the simple analytical instrument is accurate. It was found to be measured well.

4). Absorption analysis method using a simple analysis tool for measuring hypochlorous acid (free residual chlorine) as it is. The following test was performed using the apparatus 200 used in Example 1 with the pressing means 510 of the tube holder 51 functioning. The screw 510c of the pressing means 510 of the tube holder 51 was tightened, and the absorbance of hypochlorous acid was measured in a state where the distance D between the two pressing walls 510a was 7 mm. A standard solution having a hypochlorous acid concentration of 300 ppm was prepared. One simple analytical tool 1 (Kyoritsu Riken Laboratories Co., Ltd. product, Pack Test WAK-ClO (C)) was prepared, and 1.5 mL of this standard solution was sucked in and mixed well with the coloring reagent. The simple analyzer 1 was set in the tube holder 51 adjusted as described above, and the absorbance was measured. Measurement wavelengths were 526 nm and 700 nm. Absorbance was measured in the same manner for standard solutions having hypochlorous acid concentrations of 200 ppm, 50 ppm, 10 ppm, and 0 ppm. The baseline measurement was performed on the tube holder 51 without setting the simple analyzer 1, that is, on the empty tube holder 51. The shaft thickness of the body part of the resin tube of the simple analyzer used for the test was in the range of 10 to 12 mm, and the body part of the resin tube was in a pressed state. FIG. 18 shows an absorption spectrum in the entire wavelength range of a simple analyzer containing 1.5 mL of a standard solution of hypochlorous acid having each concentration. According to this absorption spectrum, the wavelength range of the absorption band of hypochlorous acid cannot be confirmed at the bottom of the short wavelength side, but is about ˜600 nm, and the maximum absorption wavelength is about ˜450 nm.

  Table 5 below shows the difference in absorbance at different wavelengths from the measured absorbance at each measurement wavelength. Further, FIG. 19 shows a calibration curve based on each measurement wavelength or its difference value and the concentration of the standard solution.

  From the absorbance values at each measurement wavelength in Table 5 and the results in FIG. 19, it was found that the relationship line based on the difference value obtained from the absorbance values at different measurement wavelengths and the concentration of the standard solution was linear. This difference value is a value obtained by subtracting the absorbance at a wavelength outside the absorption wavelength range (700 nm) from the absorbance at the absorption band wavelength (526 nm) of the hypochlorous acid that is the analysis object. In this way, by subtracting the absorbance at a wavelength outside the absorption wavelength range, the dispersion of the resin tube material is eliminated, and the color development state of the solution containing hypochlorous acid contained in the simple analyzer is substantially caused. It was found that only the absorption to be measured with high accuracy.

  The present invention is not limited to the above-described embodiments or examples, and various design changes within the scope not departing from the gist of the invention described in the claims are also included in the technical scope. .

100, 200, 300 Concentration analyzer 1 Simple analyzer 10 Resin tube 11 Coloring reagent 12 Plug member 13 Through hole 14 Knob part 15 Ear part 20 Finger 21 Air in resin tube 22 Analytical liquid (sample liquid / standard solution)
3 Light source 4 Spectrometer 5, 51, 52 Tube holder 50, 510, 520 Pressing means 510a, 520a Pressing wall 510b, 520b Spacer 510c, 520c Screw 511, 521 Base base 6, 61, 62 Light passage hole 6a, 61a, 62a Incident light hole 6b, 61b, 62b Passing light hole 7, 70 Photodetector (absorbance measuring means)
8 Data processing / calculation means (difference value calculation means / concentration calculation means)
9 Memory D Optical path length of the simple analyzer L1 Light emitted from the light source L2 Monochromatic light L20 Monochromatic light branched by the mirror L3 Light that passed through the sample liquid part of the simple analyzer 1 L30 Passed through the air part of the simple analyzer 1 Light M1, M2 Optical branching mirror

Claims (6)

A concentration analysis method for quantifying the concentration of an analyte in a sample solution by absorbance using a simple analysis tool in which a coloring reagent for the analyte is enclosed in a flexible resin tube,
(A) storing the sample solution in the resin tube;
(B) pressing at least a part of the body portion of the resin tube with a pressing means to make the optical path length of light passing through a portion of the resin tube containing the sample liquid constant;
(C) a step of measuring the first absorbance by passing light of a first wavelength through a portion in which the sample liquid containing the optical path length of the resin tube is constant;
(D) a step of measuring the second absorbance by passing light having a second wavelength through a portion in which the sample liquid containing the optical path length of the resin tube is constant;
(E) calculating a difference value between the first absorbance and the second absorbance;
(F) The difference values obtained in the step (e) and a plurality of standard solutions having different concentrations of the analyte are used in place of the sample solution, and the steps (a) to (e) are performed. A concentration analysis comprising: obtaining the concentration of the analysis object in the sample liquid by comparing the concentration of the analysis object obtained above and a calibration curve based on a difference value at each concentration. Method.   The first wavelength is any wavelength within the absorption band range of the analysis object, and the second wavelength is a wavelength outside the absorption band range of the analysis object. Concentration analysis method.   Further, a plurality of standard solutions having different concentrations of the analysis object are used in place of the sample solution, and the steps (a) to (e) are performed, respectively, so that the concentration of the analysis object and a difference value at each concentration are obtained. The concentration analysis method according to claim 1, further comprising a step of obtaining a calibration curve based thereon. A concentration analyzer that quantifies the concentration of an analyte in a sample solution by absorbance using a simple analyzer in which a coloring reagent for the analyte is enclosed in a flexible resin tube,
A light source that irradiates the resin tube containing the sample liquid with light of a first wavelength and a second wavelength;
At least one of the body portions of the resin tube supports the resin tube containing the sample solution and has a constant optical path length of light passing through the portion of the resin tube containing the sample solution. A tube holder having a pressing means for pressing the part;
Absorbance measuring means for measuring the first absorbance and the second absorbance when the portions of the resin tube containing the sample liquid are irradiated with light of the first wavelength and the second wavelength, respectively.
Difference value calculating means for calculating a difference value between the first absorbance and the second absorbance;
The difference is compared with a calibration curve based on the difference between the first absorbance and the second absorbance obtained by measuring in advance a plurality of standard solutions having different concentrations of the analyte. A concentration analyzer comprising: concentration calculating means for calculating the concentration of the liquid.   The first wavelength is any wavelength within the absorption band range of the analysis object, and the second wavelength is a wavelength outside the absorption band range of the analysis object. Concentration analyzer. A concentration analysis method for quantifying the concentration of an analyte in a sample solution by absorbance using a simple analysis tool in which a coloring reagent for the analyte is enclosed in a flexible resin tube,
(A) storing the sample solution in the resin tube so that an air portion remains;
(B) Pressing at least a part of the body portion of the body of the resin tube containing the sample solution and at least a part of the air part with a pressing means, and the optical path length of the light passing through the resin tube is constant And a process of
(C) The air in which the optical path length of the resin tube is constant while the optical path length of the resin tube is constant while measuring the absorbance of the sample liquid part by passing light through the part in which the optical path length of the resin tube is constant Measuring the absorbance of the air part by passing light through the part;
(D) calculating a difference value between the absorbance of the sample liquid portion and the absorbance of the air portion;
(E) The steps (a) to (d) are performed by using a plurality of standard solutions having the difference value obtained in the step (d) and the concentration of the analysis object in place of the sample solution. And a step of obtaining the concentration of the analysis object in the sample solution by comparing the obtained concentration of the analysis object and a calibration curve based on a difference value at each concentration. .

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