JP2004157018A - Sensitivity calibration method of fluorescence detection apparatus and fluorescence detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensitivity calibration method of a fluorescence detection apparatus for conveniently calibrating sensitivity of the fluorescence detection apparatus without using a reagent, and the fluorescence detection apparatus for adopting the method. <P>SOLUTION: The sensitivity calibration method of the fluorescence detection apparatus 1 for detecting fluorescence emitted from a sample by using a photodetector 21a, uses a fixed reference fluorescent material 100 as a sensitivity calibration reference having previously found information of fluorescence intensity detected on predetermined conditions, and corrects an output from the photodetector 21a based on the information and the output when the photodetector 21a detects the fluorescence emitted from the fixed reference fluorescent material 100. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for calibrating the sensitivity of a fluorescence detection device that detects fluorescence emitted from a sample by a photodetector, and a fluorescence detection device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, fluorescence analysis for measuring the presence and / or concentration of a measurement target by measuring fluorescence (including intensity and quenching time) of a measurement target, a reaction product of the measurement target, or a reagent reacting with the measurement target has been performed. Widely used. Fluorescence analysis has high sensitivity if the fluorescence characteristics of the measurement target are specified, and is one of important measurement means for analysis of trace components.
[0003]
For example, in Patent Document 1, the present inventor measures a water quality index such as an anionic surfactant concentration and BOD (biochemical oxygen demand) in a sample water, for example, river water or lake water using fluorescence measurement. Suggested how to.
[0004]
As a method for measuring an anionic surfactant in a sample water, a methylene blue absorption spectrophotometry (JIS K 0102, 30.1) is conventionally used. However, this method requires many reagents such as methylene blue solution, chloroform, acids, alkalis, etc., and involves complicated operations such as extraction operations, which is time-consuming and requires considerable skill. is there. Moreover, such a method cannot respond to continuous measurement. On the other hand, as a method for measuring the BOD of sample water, a standard dilution method (21 of JIS K 0102) is widely used. However, this method requires a long time of 5 days to obtain a measurement result, requires many reagents, planting, and the like, requires complicated operations, and requires considerable skill. And this method cannot respond to continuous measurement at all.
[0005]
On the other hand, according to the water quality measuring method and apparatus using the fluorescence measurement proposed by the present inventors (Patent Document 1), an anionic surfactant (particularly, a sulfonic acid type anionic surfactant) of sample water is used. Water quality indicators such as certain linear alkylbenzene sulfonates (LAS)) and BOD can be measured in a non-contact, non-reagent-less manner, and can be used for continuous measurement.
[0006]
In this method, the correlation (calibration curve) between the fluorescence intensity of a specific wavelength emitted by the standard sample water and the LAS concentration or BOD of the standard sample water when the excitation light of the specific wavelength is irradiated is obtained in advance. By utilizing this relationship, the LAS concentration or the BOD of the actual sample water is measured by performing fluorescence measurement under the same conditions.
[0007]
According to such a method, by using a calibration curve obtained in advance, when measuring the actual sample water, by simply irradiating the sample water with excitation light of a specific wavelength and measuring the fluorescence of a specific wavelength, no reagent is required. The LAS concentration can be measured without contact, and continuous measurement is possible.
[0008]
[Patent Document 1]
Japanese Patent Application No. 2001-265089
[0009]
[Problems to be solved by the invention]
However, the sensitivity of a photodetector such as a photomultiplier tube included in the fluorescence detection device may change with time. Therefore, it is desirable to periodically calibrate the sensitivity of the photodetector.
[0010]
Conventionally, sensitivity calibration of a photodetector in a fluorescence detection apparatus (hereinafter, simply referred to as “sensitivity calibration”) is performed using a sensitivity calibration reagent such as a quinine sulfate solution. Alternatively, it is conceivable to re-create a calibration curve periodically using a standard sample of the component to be measured.
[0011]
However, such a periodic calibration of the sensitivity using reagents or the rebuilding of a calibration curve using standard samples makes the operation complicated and increases running costs, and in particular, In the water quality measurement method and apparatus proposed by the inventor, the merit that the water quality index can be measured very easily without a reagent is reduced by half.
[0012]
In addition, some reagents used for sensitivity calibration change with time or are deteriorated by ultraviolet light to change their fluorescence characteristics, so that the stability as a sensitivity calibration standard cannot be maintained.
[0013]
Further, in the above-mentioned water quality measuring device, LAS, which is a component to be measured, is decomposed by ultraviolet rays. Therefore, if sensitivity calibration is performed by LAS, LAS must always be supplied, and running costs and There is a problem in terms of operation complexity.
[0014]
Further, it has been found that the sensitivity calibration reagent as described above, for example, a quinine sulfate solution, has an extremely high fluorescence intensity with respect to temperature. Therefore, when the fluorescence detection device such as the above-mentioned water quality measurement device is installed in a place where the temperature change is large, such as outdoors, the sensitivity calibration itself using the reagent becomes impossible. Alternatively, a complicated mechanism must be provided for temperature control.
[0015]
Accordingly, an object of the present invention is to provide a method for calibrating the sensitivity of a fluorescence detection device, which can extremely easily perform the sensitivity calibration of the fluorescence detection device without using any reagent, and a fluorescence detection device employing the method.
[0016]
It is another object of the present invention to provide a sensitivity calibration method capable of always performing stable sensitivity calibration without being affected by a temperature change, and a fluorescence detection apparatus employing the method.
[0017]
[Means for Solving the Problems]
The above object is achieved by a method for calibrating the sensitivity of a fluorescence detection device and a fluorescence detection device according to the present invention. In summary, a first aspect of the present invention is a method for calibrating the sensitivity of a fluorescence detection device that detects fluorescence emitted from a sample by a photodetector, wherein the information on the fluorescence intensity detected under predetermined conditions is obtained in advance. Using as a sensitivity calibration standard, correcting the output of the photodetector based on the output when the photodetector detects the fluorescence emitted by the solid standard phosphor and the information. This is a method for calibrating the sensitivity of the device. According to another embodiment of the present invention, the solid standard phosphor is disposed on an optical path from the sample to the photodetector when the photodetector detects fluorescence emitted by the sample, and Fluorescence is detected with the photodetector. In one embodiment, the solid standard phosphor is arranged on substantially the same plane as the surface of the sample facing the photodetector when the photodetector detects the fluorescence emitted from the sample.
[0018]
According to the second aspect of the present invention, a photodetector for detecting fluorescence emitted from a sample, a solid standard phosphor for which information on the intensity of fluorescence detected under predetermined conditions has been obtained in advance, and There is provided a fluorescence detection device, comprising: a correction unit that corrects an output of the photodetector based on an output when detecting fluorescence emitted from a body and the information. According to one embodiment of the present invention, the fluorescence detection device further includes a moving unit that moves the solid standard phosphor between a detection position where fluorescence can be detected by the photodetector and a retreat position where fluorescence cannot be detected. Have.
[0019]
According to the third aspect of the present invention, the photodetector for detecting the fluorescence emitted from the sample, the solid standard phosphor for which the information of the fluorescence intensity detected under predetermined conditions has been obtained in advance, and the solid standard phosphor, There is provided a fluorescence detection device comprising: a moving unit that moves between a detection position where fluorescence can be detected by a detector and a retreat position where fluorescence cannot be detected. According to one embodiment of the present invention, the fluorescence detection device further corrects the output of the photodetector based on the output when the photodetector detects the fluorescence emitted by the solid standard phosphor and the information. It has correction means.
[0020]
In one embodiment of the second and third aspects of the present invention, the fluorescence detection device further includes an excitation light source, and at the detection position, the solid standard phosphor emits fluorescence upon receiving excitation light from the excitation light source. The fluorescence is detected by the photodetector. In one embodiment, the moving means introduces the solid standard phosphor onto an optical path from the sample to the photodetector when detecting fluorescence emitted by the sample with the photodetector, and retracts from the optical path. Let it. In one embodiment, the moving means introduces the solid standard phosphor into substantially the same plane as the surface of the sample facing the light detecting means when detecting the fluorescence emitted by the sample with the photodetector. . Further, the fluorescence detecting device may further include a storage unit for storing the information.
[0021]
According to one embodiment of the present invention, the solid standard phosphor comprises a fluorescent plastic or a fluorescent glass. In a preferred embodiment, the fluorescent plastic is fluorescent acrylic. In another embodiment, the solid standard phosphor is formed by applying a fluorescent paint on a substrate. In still another embodiment, the solid standard phosphor is formed by attaching a sheet member coated with a fluorescent paint or a fluorescent sheet member on a substrate. Further, the solid standard phosphor may be further provided with dimming means. In a preferred embodiment, the solid standard phosphor has a plate shape.
[0022]
Further, according to one embodiment of the present invention, the fluorescence detection device is configured to detect the concentration of linear alkylbenzene sulfonates, BOD or water in the sample based on the output of the photodetector when detecting the fluorescence emitted from the sample. Measure the oil concentration.
[0023]
In the present specification, the term “fluorescence” refers to light emission caused by an excitation stimulus (light quantum, electron, electric field, chemical reaction, mechanical stress), and not only luminescence that disappears immediately after the stimulus is removed, but also luminescence continues thereafter. It shall include light. The excitation stimulus is preferably light (excitation light), and includes radiation such as infrared rays, X-rays, α-rays, and β-rays in addition to visible rays and ultraviolet rays.
[0024]
Further, in the present specification, ultraviolet light refers to light having a wavelength of 190 nm to 400 nm.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the sensitivity calibration method and the fluorescence detection device of the fluorescence detection device according to the present invention will be described in more detail with reference to the drawings.
[0026]
Example 1
One embodiment of a fluorescence detection apparatus to which the present invention can be applied will be described with reference to FIGS. In the present embodiment, the present invention is applied to a water quality measuring device basically the same as that described in Patent Document 1.
[0027]
This water quality measuring device irradiates sample water with ultraviolet rays of at least two different wavelengths, measures the fluorescence intensity of the specific wavelength emitted from the sample water by the ultraviolet rays of each wavelength, and obtains the fluorescence intensity information of the specific wavelength for the ultraviolet rays of each wavelength. The specific water quality index of the sample water, for example, the concentration of the anionic surfactant in the sample water and the BOD can be measured based on the above.
[0028]
Here, an example is described in which an anionic surfactant of sample water, particularly a linear alkylbenzene sulfonate (LAS), which is a sulfonic acid type anionic surfactant, is continuously measured (monitored) as a water quality index. I do.
[0029]
As shown in FIG. 10, there is a substantially linear correlation between the concentration of the LAS standard solution (about 0.1 mg / L to 3 mg / L) and the fluorescence intensity at an excitation wavelength of 210 nm and a measurement wavelength of 290 nm (correlation 1). . Similarly, the fluorescence intensities at an excitation wavelength of 230 nm and a measurement wavelength of 290 nm also have a substantially linear relationship (correlation 2). Therefore, LAS in the sample water can be quantified by measuring the fluorescence intensity at 290 nm as the measurement wavelength using 210 nm or 230 nm as the excitation wavelength.
[0030]
However, river water, lake water, and the like have different water qualities depending on the water system, and the fluorescence emitted when excited by ultraviolet rays is greatly different from each other. For this reason, it has been extremely difficult to measure a lower concentration by measuring the fluorescence intensity at a wavelength of 290 nm by any one of the above excitation wavelengths.
[0031]
Therefore, as proposed by the present inventor in Patent Document 1, the difference between the fluorescence intensities at the measurement wavelength of 290 nm when the sample water is irradiated with the excitation wavelengths of 230 nm and 210 nm, respectively, and the correlation between this and the LAS concentration. (Correlation 3) is used as a calibration curve. That is, at the time of measurement, the sample water is irradiated with ultraviolet rays having center wavelengths of 210 nm and 230 nm, and the fluorescence (measurement wavelength of 290 nm) excited by the ultraviolet rays of each wavelength and emitted from the sample water is detected. Then, the difference is determined, and the LAS concentration is determined using the above calibration curve.
[0032]
As a result, even when the blank changes due to sample water of different water quality, the effect can be reduced or eliminated, and the measurement of a lower concentration (for example, 0.2 mg / L or less) can be performed with extremely high accuracy. It can be carried out.
[0033]
As schematically shown in FIG. 1, a water quality measurement device 1 as a fluorescence detection device has a detection unit 2, a control unit 3, a sample tank 4 as a sample water storage unit, and an operation unit 5. The water quality measuring device 1 continuously measures the LAS concentration in the sample water continuously introduced into the sample tank 4 at a predetermined flow rate.
[0034]
The sample water flows into a sample tank 4 from a desired sample water supply source, for example, a river via a pipe 62 connected to the inlet 41 by a pump 61. The sample water introduced into the sample tank 4 overflows and is discharged from the outlet 42 to a predetermined discharge destination, for example, a sample water supply source, through a pipe 63 connected thereto. The introduction of the sample water from the sample water supply source into the pipe 62 and the drainage of the sample water from the pipe 63 are controlled by valves 64 and 65, respectively.
[0035]
The detection unit 2 irradiates the sample water introduced into the sample tank 4 with a predetermined excitation light, that is, ultraviolet rays having a specific wavelength (230 nm, 210 nm) in the present embodiment, and irradiates a specific wavelength (290 nm) emitted by the sample water. ) And outputs an electric signal corresponding to the intensity to the control unit 3.
[0036]
FIG. 2 shows the detecting unit 2 of the water quality measuring device 1 in more detail. The light projecting unit 10 of the detecting unit 2 includes a light source 10a, a lens system 12, an excitation wavelength selecting unit 13, and the like. In this embodiment, a Xe flash lamp (xenon discharge tube) that emits light having a wavelength of 200 nm to 800 nm is used as the light source 10a. The light emitted from the light source 10a is guided to the excitation wavelength selecting means 13 by the lens system 12, and further directed to the dichroic mirror 14. In the present embodiment, the excitation wavelength selecting unit 13 includes a first optical filter 13a serving as an interference film band-pass filter that transmits excitation light having a center wavelength of 210 nm, and a second optical filter that transmits excitation light having a center wavelength of 230 nm. And two optical filters 13b. The excitation wavelength selecting means 13 supports the first and second optical filters 13a and 13b on a filter support 13c which is a rotating body. The filter support 13c is rotationally driven by an instruction from the control unit 3 described later, and sequentially arranges desired optical filters at positions where light beams from the light source 10a pass. Thus, the desired excitation light is irradiated to the sample water at a desired timing.
[0037]
The dichroic mirror 14 transmits light having a wavelength of 260 nm or more and reflects light having a shorter wavelength. Therefore, ultraviolet rays having wavelengths of 210 nm and 230 nm are reflected by the dichroic mirror 14. The excitation light reflected by the dichroic mirror 14 has its optical axis bent at a substantially right angle, and is directed substantially vertically downward in this embodiment. Then, the excitation light is guided along the optical path 16 and irradiates the sample water in the sample tank 4. A lens system 15 is disposed in the optical path 16, and the excitation light is focused on a substantially liquid surface of the sample water.
[0038]
On the other hand, the fluorescence emitted from the sample water irradiated with the excitation light as described above is guided to the dichroic mirror 14 via the lens system 15, further passes through the dichroic mirror 14, and travels to the fluorescence detector 21.
[0039]
The fluorescence detector 21 includes a photodetector 21a, a third optical filter 19 serving as an interference film band-pass filter serving as a spectral unit, a lens system 20, and the like. In this embodiment, the third optical filter 19 transmits light having a center wavelength of 290 nm. Then, the fluorescent light transmitted through the third optical filter 19 is focused by the lens system 20 on the photodetector 21a. In this embodiment, a photomultiplier is used as the photodetector 21a.
[0040]
The photodetector 21a emits an electric signal corresponding to the detected fluorescence intensity. This signal is input to the control unit 3 via a detection circuit (not shown) including a current-voltage converter (amplifier) and an A / D converter (FIG. 1).
[0041]
The light emitted from the light projecting unit 10 and transmitted through the dichroic mirror 14 is focused by the lens system 17 on the reference light detector 18a in the reference light receiving unit 18. The reference photodetector 18a emits a signal corresponding to the amount of received light, and this signal is fed back for controlling the amount of light of the light source 10a. Thereby, the light amount of the light source 10a is stabilized. All the optical components in the detection unit 2 are housed in the light shielding case 22, and the light path 16 and the sample tank 4 connected to the light shielding case 22 are also shielded from external light.
[0042]
The control unit 3 includes a calculation unit 31, a storage unit 32, and the like. The control unit 3 comprehensively controls the operation of the apparatus according to a program stored in the recording unit 32, and outputs the output from the detection unit 2 and stores the output in the storage unit 32. Based on the obtained information, a signal corresponding to the LAS concentration in the sample water is generated.
[0043]
That is, the control unit 3 turns on the light source 10a at a predetermined timing, moves the first optical filter 13a and the second optical filter 13b of the excitation wavelength selection unit 13 to the light transmission position, and sequentially sets the excitation wavelength to 210 nm. , 230 nm of ultraviolet light is applied to the sample water introduced into the sample tank 4. When a signal corresponding to the intensity of the fluorescence at the measurement wavelength (290 nm) sensed by the photodetector 10a is input to the control unit 3, the arithmetic unit 31 synchronizes with the operation of the rotating body 13c of the excitation wavelength selection unit 13. Then, while recognizing which of the excitation wavelengths the fluorescence intensity is, the intensity is stored in the storage unit 32 or the arithmetic unit 31 in a built-in storage unit.
[0044]
The storage means 32 previously stores information on a calibration curve as shown in FIG. 10 (information indicating the relationship between the difference in the fluorescence intensity at the measurement wavelength of 290 nm at each of the excitation wavelengths of 230 nm and 210 nm and the LAS concentration (correlation 3). ) Is stored. The calculating means 31 calculates based on the detected value information of the fluorescence intensity obtained as described above and the information of the calibration curve stored in the storage means 32 in advance, and calculates information corresponding to the LAS concentration in the sample water. Generate. Further, the calculating means 31 generates a signal for causing the display means 51 such as a liquid crystal display of the operation unit 5 to display the information indicating the LAS concentration measured value in a desired display form based on the information. The operation unit 5 includes a display unit 51 for displaying a measured value, and an input unit 52 for setting the device, starting and stopping measurement, inputting desired data, and the like.
[0045]
The information on the calibration curve is input, for example, by performing measurement using a predetermined standard sample water before the actual sample water measurement, such as when the water quality measurement device 1 is shipped from a factory, or from the operation unit 5. By doing so, it can be stored in any form such as a table or an arithmetic expression.
[0046]
Note that an external device such as a personal computer, which is communicably connected to the detection unit 2, can be used as the control unit 3. In this case, the display means 51 and the input means 52 may be attached to the computer.
[0047]
Further, the light source 10a is not limited to a Xe flash lamp (xenon discharge tube). ₂ A lamp (deuterium discharge tube) may be used, or a monochromatic light source such as a laser light source that emits light of a desired wavelength may be used if available. Further, as the photodetector 21a, a photodiode, a phototransistor, an avalanche photodiode, or the like can be appropriately used in addition to the photomultiplier tube.
[0048]
FIG. 3 shows the arrangement relationship between the detection unit 2 and the sample tank 4 in this embodiment in more detail. As described above, the sample water flows into the sample tank main body 40 from the inflow port 41. The sample tank main body 40 has a substantially cylindrical shape and is arranged to be inclined with respect to the direction of gravity. When the sample tank body 40 is filled with the sample water, the sample water overflows from the upper opening (measurement opening) 43 of the sample tank body 40 and is discharged from the outlet 42 through the outflow channel 42a. You. In a state where the sample water is supplied to the measurement tank main body 40 at a predetermined flow rate, a substantially flat upper surface of the sample water (hereinafter, referred to as “measurement surface”) is formed in the measurement opening 43. The detection unit 2 irradiates the measurement surface of the sample water with the excitation light so as to be substantially focused.
[0049]
The detection unit 2 is appropriately positioned and installed on the detector support 71. The detector support 71 can swing about a rotation shaft 73, and the operator can use the handle 72 or the like to move the detector support 71 to the sample in the sample tank 4 when desired. The detection unit 2 can be moved between a predetermined closed position where the fluorescence from water can be detected by the detection unit 2 and an open position where the detection unit 2 (the detector support 71) is retracted from above the sample tank 4. When the detector support 71 is retracted from the upper part of the sample tank 4 in this way, the measurement opening 43 can be opened.
[0050]
According to the above water quality measuring device, an anionic surfactant, particularly a sulfonic acid type anionic surfactant (eg, LAS) is used as a water quality index (water contaminant) for sample water, for example, river water, lake water and the like. The concentration can be measured continuously without contact and without reagents.
[0051]
Now, as described above, the sensitivity of the photodetector 21a may change with time. Therefore, it is desirable to perform sensitivity calibration periodically. In particular, it can be said that this periodic sensitivity calibration is indispensable when trying to measure a low-concentration measurement object with high accuracy.
[0052]
On the other hand, as conventionally described, periodic sensitivity calibration using a sensitivity calibration standard reagent such as a quinine sulfate solution with a fixed concentration, as described above, requires the stability of the reagent over time or ultraviolet light, as described above. There are problems in the stability of fluorescence intensity with respect to temperature, operability, cost, and the like. Particularly, in the water quality measurement device 1 of the present embodiment, the merit of reagent-free measurement is reduced by half.
[0053]
Therefore, in the present embodiment, a sensitivity calibration method described below is adopted.
[0054]
According to the present invention, the sensitivity calibration method according to the present invention uses, as a sensitivity calibration standard, a solid standard phosphor in which information on the fluorescence intensity detected under predetermined conditions is obtained in advance, and the output of the photodetector is based on the information. And correcting.
[0055]
That is, the solid-state standard phosphor emits the fluorescence intensity (light intensity) emitted under predetermined conditions (including excitation conditions, measurement wavelengths, arrangement relations, and the like) using a fluorescence detection device that has been calibrated for sensitivity when shipped from the factory. The output of the detector, the indicator value including the fluorescence intensity value derived from the output and the indicated value of the concentration of the object to be measured are calibrated (hereinafter, the calibrated value is referred to as “calibration value”).
[0056]
Thus, thereafter, by using the calibrated solid standard phosphor as a sensitivity calibration standard, sensitivity calibration can be performed without a reagent.
[0057]
Solid standard phosphors include any available solid phosphor that upon excitation stimulus emits constant fluorescence when guided to a photodetector so that the sensitivity of the photodetector can be calibrated. The excitation stimulus is preferably light (excitation light). Most preferably, when irradiating a predetermined excitation light that is the same as that used at the time of measuring the sample of the fluorescence detection device, the fluorescence detection device includes fluorescence including a measurement wavelength used at the time of measuring the sample of the fluorescence detection device. A solid standard phosphor that emits at an appropriate intensity within the measurement range of the photodetector is used.
[0058]
The theory and technology behind the phosphor (fluorescent material) that can be used in the present invention are well known to those skilled in the art, and any available phosphor is within the scope of the design change of the present invention.
[0059]
Preferred solid standard phosphors include a fluorescent plastic, a fluorescent glass, a phosphor (such as a fluorescent paint) applied on a substrate, or a phosphor having an intermediate phosphor layer between a plurality of substrates.
[0060]
As the fluorescent plastic, there is a plastic molded by adding a phosphor. The phosphor may be any of an inorganic phosphor (inorganic fluorescent pigment), an organic fluorescent pigment, and a fluorescent dye. For example, a fluorescent acrylic plate is available from Kanase Co., Ltd. under the trade name "Canaselite" and from Mitsubishi Rayon Co., Ltd. under the trade name "Acrylite".
[0061]
Inorganic phosphors (inorganic fluorescent pigments) used alone or in combination with other components as an additive of a fluorescent plastic or as a coating material applied to a substrate include Ca, Ba, Mg, Zn, and Cd. Of oxides, sulfides, silicates, phosphates, tungstates and the like as main components, to which Mn, Ag, Cu, Sb, Pb, etc. are added as an activator and calcined; Phosphate phosphors and rare earth phosphors using a rare earth element as an activator. For example, fluorescent powder materials that can be processed into powder coatings, paints, inks, dyes, resin moldings, glazes, etc., under the trade name “Ultra Glow Series” from Nichia Corporation it can.
[0062]
The organic fluorescent pigment used alone or in combination with other components as an additive of a fluorescent plastic or as a paint applied to a substrate typically comprises colorless resin particles. Some include dyes that are colored and can emit strong fluorescence in solution. In such a fluorescent pigment, fluorescence from the pigment is added to the reflected light. Many fluorescent pigments are made by bulk polymerization of a dye-loaded polymer. For example, a dye having fluorescence is produced by dissolving in water together with a synthetic resin having good light transmittance and not hindering the dye, polymerizing and solidifying, and then pulverizing. Examples of the dye used for the fluorescent pigment include Rhodamine B (registered trademark), Rhodamine F5G (registered trademark) (BASF), Xylene Red B (registered trademark) (Sandoz Chemical Company), and Fluorescent Yellow Y (registered trademark) (L. B. Holliday), Maxilon Brilliant Flavine 10 GFF (registered trademark) (CIBA-GEIGY), Alberta Yellow (registered trademark), Potomac Yellow (registered trademark) (registered trademark of Day-GloColor), MacroFlow Trademark, YellowMacRox (Bayer). These fluorescent pigments can be used as fluorescent paints and printing inks, and can also be used in the production of synthetic resins (fluorescent plastics).
[0063]
As the fluorescent glass, there is a glass in which a fluorescent substance is formed in a glass structure. For example, from Sumita Optical Glass Co., Ltd., trade names "Lumiras-G9" (main emission wavelength 540 nm, excitation wavelength range 200 to 390 nm), "Lumiras-R7" (main emission wavelength 610 nm, excitation wavelength range 200 to 420 nm), As "Lumilas-B" (main emission wavelength: 405 nm, excitation wavelength range: 200 to 400 nm), functional fluorescent glass in which glass contains rare earth ions serving as fluorescent active ions can be obtained.
[0064]
The solid standard phosphor is such that the fluorescence emitted when the predetermined excitation light is irradiated is within a predetermined measurement range of the photodetector provided in the fluorescence detection device, alone or with an appropriate dimming means. They can be used in combination.
[0065]
As the dimming unit, for example, a material that absorbs fluorescence including light having a measurement wavelength or absorbs excitation light, such as glass or plastic, can be used. In use, such a material may be disposed between the solid phosphor main body and the photodetector or between the excitation light source and the solid phosphor main body.
[0066]
The shape of the solid standard phosphor is not particularly limited, but design such as easy setting (adjustment) of the intensity of the fluorescence emitted by the solid standard phosphor, easy handling in a fluorescence detection device, and easy availability. What is necessary is just to select suitably from the above restrictions. From these viewpoints, the solid standard phosphor preferably has a plate shape.
[0067]
More specifically, FIG. 4 shows an embodiment of the solid standard phosphor 100 which can be used for sensitivity calibration of the water quality measuring device 1 of the present embodiment. The solid standard phosphor 100 of FIG. 4 is formed by fixing a fluorescent plate 101 as a solid phosphor main body and a dimming plate 102 as dimming means with screws 103 as fixing means.
[0068]
The combination of the fluorescent plate 101 and the dimming plate 102 and the setting of the thickness may be appropriately set so as to obtain the fluorescence intensity within the measurement range of the photodetector. For example, a desired fluorescent intensity can be obtained by changing the type and thickness of the dimming plate 102 with respect to the available fluorescent plate 101.
[0069]
The fixing means is not limited to the screwing, and any appropriate means such as heat bonding and an adhesive can be used.
[0070]
As shown in FIG. 5, if the fluorescent plate 101 alone can obtain a fluorescent intensity within a desired range, there is no need to provide the dimming plate 102. Further, as the fluorescent plate 101, a plurality of the same type or different types may be used.
[0071]
As shown in FIG. 6A, a fluorescent paint (for example, including the above-described fluorescent pigment as a solid phosphor body) is formed on a base 104 made of a suitable plastic plate, glass plate, metal plate or the like. The solid standard phosphor 100 may be formed by applying a fluorescent thin film) 101a. Alternatively, as shown in FIG. 6B, a seal (a resin or the like) coated with a fluorescent paint or a fluorescent sheet (a resin or the like) itself 101b to which the adhesive 105 is applied is used as a phosphor body. It may be attached to the base 104. Further, as shown in FIG. 6C, for example, a solid phosphor main body is provided between a plurality of substrates 104a and 104b made of, for example, a plastic plate, a glass plate, or the like (which may function as dimming means). For example, a fluorescent coating (fluorescent thin film) 101c containing a fluorescent pigment as described above may be held as an intermediate layer. 6 (a), (b) and (c) can also be used in combination with the dimming means as appropriate.
[0072]
In the case where the base member 104 is provided with a fluorescent paint or a fluorescent seal 104, the fluorescent plate 101 such as a fluorescent plastic or a fluorescent glass (FIG. 4 or FIG. 5) is considered because peeling or turning over may occur due to long-term use. It is more preferable that a phosphor is incorporated in the structure (composition).
[0073]
(Specific example 1)
As a fluorescent plate 101 shown in FIG. 6996 (manufactured by Kanase Industries, Ltd.), and as the dimming plate 102, a 3 mm-thick Sumipex E No. transparent acrylic plate. 000 (manufactured by Sumitomo Chemical Co., Ltd.), screws 103 were used to close each of the four corners of a 85 mm × 72 mm rectangular plate.
[0074]
(Specific example 2)
As a fluorescent plate 101 shown in FIG. 993 (manufactured by Mitsubishi Rayon Co., Ltd.), and as the dimming plate 102, Sumipex E No. Using 915 (Sumitomo Chemical Co., Ltd.), the vicinity of each of the four corners of the rectangular plate material of 85 mm × 72 mm was fixed with screws 103.
[0075]
(Specific example 3)
As the fluorescent screen 101 shown in FIG. 4, Lumiras B (Sumita Optical Glass Co., Ltd.) having a thickness of 2 mm, which is a fluorescent glass, is used. Using 993 (manufactured by Mitsubishi Rayon Co., Ltd.), the vicinity of each of the four corners of a rectangular plate of 85 mm × 72 mm was bonded.
[0076]
Next, the sensitivity calibration operation in the water quality measuring device 1 of the present embodiment will be further described.
[0077]
For example, at the time of shipment from a factory, the solid standard phosphor 100 uses a standard fluorescence detector that has been sensitivity-calibrated with a standard reagent for sensitivity calibration, and uses a standard fluorescence detector that has been subjected to the same conditions as when the sample is measured in the water quality measurement device 1 to solid-state. By irradiating the standard phosphor, fluorescence under the same conditions as when measuring the sample in the water quality measuring device 1 is detected, and information on the fluorescence intensity (output of the photodetector, the fluorescence intensity value derived from the output, and the concentration of the measurement object) Is included as calibration value information unique to the solid-state standard phosphor 100.
[0078]
More specifically, in the present embodiment, a standard device having the same configuration as that of the water quality measuring device 1 is used, and the same position (the optical path length between the light source 10a and the photodetector 21a, etc.) ), The solid standard phosphor 100 is arranged. The solid standard phosphor 100 is irradiated with ultraviolet rays having excitation wavelengths of 210 nm and 230 nm, and the difference in the fluorescence intensity at the measurement wavelength of 290 nm at that time is detected, and the LAS concentration value (mg / L) indicated by the water quality measurement device 1 is obtained. The solid standard phosphor 100 was graduated. However, the calibration value is not limited to being calibrated as the LAS concentration indication value, but may be calibrated in another form such as the output voltage value of the photodetector 21a.
[0079]
When performing the sensitivity calibration, the measurement unit 43 is retracted from the upper part of the sample tank 4 as described above, thereby opening the measurement opening 43 of the sample tank 4, and the edge of the measurement opening 43. The solid standard phosphor 100 is placed on 43a (FIG. 3).
[0080]
When the solid standard phosphor 100 shown in FIG. 4 is used, the light-reducing plate 102 is placed on the side of the detection unit 2, that is, on the upper side. When using the solid standard phosphors shown in FIGS. 6A and 6B, the solid phosphor main bodies 101 a and 101 b are, of course, placed so as to be on the detection unit 2 side.
[0081]
As a result, when the detection unit 2 is returned to the predetermined closed position, the solid standard phosphor 100 is located at a detection position where fluorescence can be detected by the photodetector 21a. Is arranged on the optical path from the measurement surface of the sample to the photodetector 21a. At this detection position, the solid standard phosphor 100 is irradiated with excitation light from the light source 10a. Further, in the present embodiment, the solid standard phosphor 100 is arranged on substantially the same plane as the measurement surface of the sample in the sample tank 4 when measuring the sample of the water quality measuring device 1.
[0082]
The detection unit 2 is returned to a predetermined measurement position, and in the sensitivity calibration mode, the solid standard phosphor 100 emits excitation light having the same wavelength as that at the time of graduation from the light projecting unit 10, and the solid standard phosphor 100 emits at that time. The intensity of the fluorescence having the same wavelength as that at the time of setting the scale is detected by the photodetector 21a. Then, an input for correcting the output of the photodetector 21a is made from the input means 52 provided in the operation unit 5 so that the indicated value matches the calibration value of the solid standard phosphor 100. After that, until the next sensitivity correction, an arithmetic processing is performed in consideration of the correction value at the time of sample measurement, and the LAS concentration is indicated.
[0083]
For example, when the indicated value is lower than the calibration value, an input for setting a correction value for increasing the output of the photodetector 21a is made so as to compensate for the difference. Thus, the subsequent instruction value is calculated based on the result obtained by adding the correction value to the photodetector 21a.
[0084]
Note that the correction method itself is optional in the present invention. For example, it is possible to provide a key for changing the indicated value so as to have the same value as the calibration value during the sensitivity calibration mode, and the calculation means 31 may calculate the correction value based on the input. Alternatively, by inputting or once inputting the calibration value and storing it in the storage means 32, after the fluorescence measurement is started by the sensitivity calibration start key, the arithmetic means 31 automatically detects the fluorescence detection result. The correction value may be calculated. These correction methods themselves are common to those skilled in the art, and may be appropriately selected from available methods and used.
[0085]
(Test Example 1)
Next, the stability of the sensitivity calibration using the solid standard phosphor 100 was tested.
[0086]
The chart shown in FIG. 7 shows the result of detecting the difference in the fluorescence intensity at the measurement wavelength of 290 nm emitted by the solid standard phosphor 100 of the specific example 1 due to the excitation wavelengths 210 nm and 230 nm while changing the environmental temperature of the water quality measurement device 1. Show.
[0087]
As shown in the figure, even when the environmental temperature of the water quality measuring device 1 is changed from about −5 ° C. to 45 ° C. and the bottom temperature of the detection unit 2 is changed from about 1 ° C. to 42 ° C., It can be seen that the fluorescence intensity is extremely stable (the fluctuation is about 1.9% with respect to the full scale (100%) of the detector sensitivity), and is hardly affected by the temperature.
[0088]
Similar tests were performed for Examples 2 and 3, but the fluorescence intensity was extremely stable with temperature change.
[0089]
On the other hand, the chart in FIG. 8 shows the fluorescence at an excitation wavelength of 320 nm and a measurement wavelength of 440 nm when an aqueous quinine sulfate solution (100 μg / l) was used as a sensitivity calibration reagent and the temperature was changed to 27 ° C., 6 ° C., and 45 ° C. Indicates strength.
[0090]
As shown in the figure, the fluorescence intensity of the aqueous quinine sulfate solution is extremely sensitive to temperature change (the fluctuation is 36.5% with respect to the full scale (100%) of the detector sensitivity), and it is difficult to obtain a stable fluorescence intensity. could not.
[0091]
As described above, the solid standard phosphor 100 has extremely stable fluorescence intensity with respect to temperature changes. For example, like the water quality measuring device 1 of the present embodiment, the fluorescence detection device is installed outdoors, Even when it is expected that the temperature changes drastically, it is possible to always perform stable sensitivity calibration without being affected by the temperature. Thus, there is no need to provide special temperature control means, and there is also an effect of cost reduction.
[0092]
As described above, according to the present embodiment, sensitivity calibration can be performed extremely easily without a reagent and stably without being affected by a change in temperature.
[0093]
Example 2
In the present embodiment, a water quality measuring device substantially similar to that of the first embodiment is provided with an automatic sensitivity calibration mechanism. Elements having the same configurations and functions as those of the water quality measurement device 1 of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0094]
FIG. 9 schematically shows the automatic sensitivity calibration mechanism of the present embodiment.
[0095]
In the present embodiment, the water quality measuring device 1 includes a moving unit 80 for moving the solid standard phosphor 100 between a detection position where fluorescence can be detected by the photodetector 21a and a retreat position where fluorescence cannot be detected. In the present embodiment, at the detection position, the solid standard phosphor 100 receives the excitation light from the excitation light source 10a and emits fluorescence, and the fluorescence is detected by the photodetector 21a. When the fluorescence emitted from the sample in the sample tank 4 is detected by the photodetector 21a, a solid standard phosphor can be introduced on the optical path from the sample to the photodetector 21a, and can be evacuated from the optical path. As in the first embodiment, the solid standard phosphor 100 can be configured to be introduced on substantially the same plane as the measurement plane of the sample when measuring the sample.
[0096]
More specifically, in this embodiment, the moving means 80 of the solid standard phosphor 100 is a driving source 81, a driving transmitting means 82, and a support member for the solid standard phosphor that is moved by the driving source 81 via the driving transmitting means 82. 83.
[0097]
Such a moving means 80 may have any structure. For example, the moving means 80 moves the solid standard phosphor 100 between the detection position and the retreat position by reciprocating movement on the same straight line, or swinging or rotating. Configuration. That is, for example, the driving force of a driving source 81, which is a motor, is transferred to a supporting member 83 slidable along guide means (rails, columns, etc.) via a drive train 82 such as a gear train and a pulley or a cam. Thus, the solid standard phosphor 100 can be reciprocated between the detection position and the retreat position. Further, the driving force of the driving means 81 as a motor is transmitted to a rotating body as a support member 83 via a gear train as a driving transmitting means, and the solid standard phosphor 100 eccentrically attached to the rotating body is moved. It can be rotated between the detection position and the retracted position. The configuration of the drive mechanism is only a design choice for those skilled in the art and is within the scope of the present invention.
[0098]
Thereby, the solid standard phosphor 100 can be automatically arranged at a predetermined position, and the operability is further improved.
[0099]
In the water quality measuring device 1 of the present embodiment, the control unit 3 controls the output when the photodetector 21a detects the fluorescence emitted from the solid standard phosphor 100 and the fluorescence of the solid standard phosphor 100 that has been calibrated in advance. It functions as correction means for correcting the output of the photodetector 21a based on the intensity information (calibration value), and automatically corrects the output of the photodetector 21a.
[0100]
The control unit 3 executes the sensitivity calibration mode, for example, according to an instruction of the operator from the input unit 52 of the operation unit 5 or every predetermined period while continuously measuring the LAS concentration in the sample water. At this time, the drive mechanism 80 is controlled to introduce the solid standard phosphor 100 to the detection position. Then, the solid-state standard phosphor 100 is irradiated with predetermined excitation light, and the fluorescence at that time is detected by the photodetector 21a.
[0101]
For example, when the water quality measuring device 1 is shipped from a factory, the storage unit 32 of the control unit 3 previously stores the calibration value of the solid standard phosphor 100 graduated as described in the first embodiment, Alternatively, when the operator once stores the data by inputting, the arithmetic unit 31 of the control unit 3 performs the light detection based on the detection result of the photodetector 21a and the calibration value stored in the storage unit 32 in advance. The correction value of the output value of the heater 21a can be automatically calculated. Then, until the next sensitivity calibration, the LAS concentration indication value is calculated in consideration of the correction value.
[0102]
As described above, according to the present embodiment, the arrangement of the sensitivity calibration standard for the solid standard phosphor can be automated, and further, the sensitivity calibration can be automated. In particular, in a fluorescence detection device that performs continuous measurement like the water quality measurement device 1 of the present embodiment, the advantages of continuous measurement and automatic measurement can be obtained to the maximum.
[0103]
In each of the above embodiments, the case where the present invention is applied to the water quality measuring device 1 for measuring the LAS concentration in the sample water has been described, but the present invention is not limited to this. As proposed by the present inventor in Patent Document 1, the BOD of a sample water can be measured by utilizing the correlation between the BOD and the fluorescence intensity of the sample water at a specific excitation wavelength / measurement wavelength ( Patent Document 1). FIG. 11 shows (1) the relationship between the BOD and the fluorescence intensity at an excitation wavelength of 230 nm and a measurement wavelength of 420 nm, (2) the relationship between the BOD and the fluorescence intensity at an excitation wavelength of 210 nm and a measurement wavelength of 420 nm, and (3) the BOD. The relationship between the excitation light wavelengths of 230 nm and 210 nm and the difference in fluorescence intensity at a measurement wavelength of 420 nm is shown. As in the case of the LAS concentration in the above-described embodiment, in particular, by utilizing the correlation of (3), the BOD of the sample water can be measured with high accuracy and continuously without using any reagent ( Patent Document 1). Further, similarly to the measurement of the LAS concentration and the BOD, the oil concentration in the sample water can be measured by utilizing the correlation between the oil concentration in water and the fluorescence intensity of the sample water at the specific excitation wavelength and the measurement wavelength. In this case, by setting the excitation wavelength to 365 nm and the measurement wavelength to 440 nm or more (detecting the maximum light intensity at 440 nm or more), a good correlation is obtained between the oil-in-water concentration and the fluorescence intensity. By applying the sensitivity calibration method according to the present invention also to these BOD and oil-in-water fluorescence measurements, stable sensitivity calibration can be performed without a reagent.
[0104]
Furthermore, in the present invention, the fluorescence (including intensity and quenching time) of the measurement object, the reaction product of the measurement object, or the reagent reacting with the measurement object is measured by detecting the fluorescence emitted from the sample by the photodetector. However, the present invention can be widely applied to any fluorescence detection device that measures the presence and / or concentration of a measurement target or the fluorescence characteristics (fluorescence spectrum, excitation spectrum, and the like) itself.
[0105]
For example, as an example, a method for synthesizing and detecting or quantifying a phosphor containing a test substance includes a uranium quantification method. A method of converting a non-fluorescent substance into a fluorescent substance by a chemical reaction and using the fluorescence for analysis is a method of analyzing aluminum. Further, there is a thallium measurement method by measuring the fluorescence quenching of rhodamine B by utilizing the disappearance of fluorescence due to reaction with a sample using a fluorescent substance as a reagent. In addition, neutralization, oxidation-reduction, precipitation and complex titration using the generation, extinction or discoloration of the fluorescence of the fluorescent indicator to indicate the end point of the titration, or by measuring the luminescence by oxidation of formaldehyde in a basic solution Formaldehyde measurement, sulfur dioxide (SO ₂ ) By measuring the emission intensity of the pyrolysis products ₂ Chemiluminescence measurement such as concentration measurement (dry AP meter) is also mentioned as an example. In a fluorescent immunoassay (fluorescent immunoassay), an antigen or antibody is labeled with a fluorescent substance, and the antigen-antibody reaction is quantitatively traced by utilizing the decrease in fluorescence intensity due to the antigen-antibody reaction to measure the antigen or antibody. .
[0106]
As described above, in the present invention, in a fluorescence detection device used for a wide range of fluorescence analysis methods, for example, the labor of re-creating a calibration curve can be omitted, and low-cost, stable reagent-free and simple sensitivity calibration can be performed. It is extremely useful in that it can be performed.
[0107]
【The invention's effect】
As described above, according to the present invention, a method of calibrating the sensitivity of a fluorescence detection device that detects fluorescence emitted from a sample by a photodetector is a solid-state standard fluorescence in which information on the fluorescence intensity detected under predetermined conditions is obtained in advance. The body is used as a sensitivity calibration standard, and the photodetector is configured to correct the output of the photodetector based on the output when the fluorescence detected by the solid standard phosphor is detected and the above information. Thus, the sensitivity calibration of the fluorescence detection device can be performed extremely easily, and stable sensitivity calibration can be always performed without being affected by a temperature change.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of one embodiment of a fluorescence detection device to which the present invention can be applied.
FIG. 2 is a schematic configuration diagram illustrating a detection unit of the fluorescence detection device of FIG. 1 in more detail;
FIG. 3 is a front view showing a positional relationship between a detection unit of the fluorescence detection device of FIG. 1 and a sample tank.
FIG. 4 is a side view showing one embodiment of a solid standard phosphor.
FIG. 5 is a side view showing another embodiment of the solid standard phosphor.
FIGS. 6A, 6B and 6C are side views showing still another embodiment of the solid standard phosphor.
FIG. 7 is a chart showing the stability of sensitivity calibration when a solid standard phosphor according to the present invention is used as a sensitivity calibration standard.
FIG. 8 is a chart showing the stability of sensitivity calibration when a quinine sulfate solution is used as a sensitivity calibration standard according to a conventional method.
FIG. 9 is a schematic view of another embodiment of the fluorescence detection device according to the present invention.
FIG. 10 is a graph showing the relationship between LAS concentration and fluorescence intensity.
FIG. 11 is a graph showing the relationship between BOD and fluorescence intensity.
[Explanation of symbols]
1 Water quality measurement device (fluorescence detection device)
2 Detector
3 control part
4 Sample tank (sample water storage section)
10 Emitter
10a light source
21 Fluorescence detector
21a Photodetector
31 arithmetic means
32 storage means
100 solid standard phosphor
101 Solid phosphor body (fluorescent acrylic plate, fluorescent glass)
102 Dimming means
103 screw (fixing means)
104 base
105 adhesive (fixing means)

Claims (25)

In a sensitivity calibration method for a fluorescence detection device that detects fluorescence emitted from a sample by a photodetector, information on fluorescence intensity detected under predetermined conditions is obtained in advance using a solid standard phosphor as a sensitivity calibration standard, Correcting the output of the photodetector on the basis of the output when detecting the fluorescence emitted from the solid standard phosphor and the information. 2. The method according to claim 1, wherein the solid standard phosphor includes a fluorescent plastic or a fluorescent glass. 3. The method of claim 2, wherein the fluorescent plastic is fluorescent acrylic. 2. The method according to claim 1, wherein the solid standard phosphor is formed by applying a fluorescent paint on a substrate. 2. The method according to claim 1, wherein the solid standard phosphor is formed by attaching a sheet member coated with a fluorescent paint or a fluorescent sheet member on a substrate. The sensitivity calibration method for a fluorescence detection device according to any one of claims 1 to 5, wherein the solid standard phosphor is further provided with a dimming unit. The sensitivity calibration method for a fluorescence detection device according to claim 1, wherein the solid standard phosphor has a plate shape. The solid standard phosphor is disposed on an optical path from the sample to the photodetector when the photodetector detects the fluorescence emitted by the sample, and the fluorescence is detected by the photodetector. The sensitivity calibration method for a fluorescence detection device according to any one of claims 1 to 7. 9. The fluorescence detection method according to claim 8, wherein the solid standard phosphor is disposed substantially on the same plane as a surface of the sample facing the photodetector when the photodetector detects fluorescence emitted from the sample. How to calibrate the sensitivity of the device. A photodetector that detects the fluorescence emitted from the sample, a solid standard phosphor in which information on the intensity of the fluorescence detected under predetermined conditions is obtained in advance, and when the photodetector detects the fluorescence emitted by the solid standard phosphor. Correction means for correcting the output of the photodetector based on the output of the photodetector and the information. 11. The fluorescence detecting device according to claim 10, further comprising a storage unit for storing the information. 12. The fluorescent light according to claim 10, further comprising moving means for moving the solid standard phosphor between a detection position where fluorescence can be detected by the photodetector and a retreat position where fluorescence cannot be detected. Detection device. A photodetector that detects fluorescence emitted from a sample, a solid standard phosphor in which information on the fluorescence intensity detected under predetermined conditions is obtained in advance, and the solid standard phosphor can be used to detect fluorescence with the photodetector. Moving means for moving between a detection position and a retreat position where detection is not possible. 14. The apparatus according to claim 13, further comprising a correction unit configured to correct an output of the photodetector based on an output when the photodetector detects fluorescence emitted from the solid standard phosphor and the information. Fluorescence detector. 15. The fluorescence detecting device according to claim 14, further comprising a storage unit for storing the information. 13. The apparatus according to claim 12, further comprising an excitation light source, wherein the solid standard phosphor at the detection position emits fluorescence upon receiving the excitation light from the excitation light source, and the fluorescence is detected by the photodetector. 16. The fluorescence detection device according to any one of Items 15 to 15. The moving means introduces the solid standard phosphor onto the optical path from the sample to the photodetector when detecting the fluorescence emitted by the sample with the photodetector, and retreats from the optical path. The fluorescence detection device according to any one of claims 12 to 16. The said movement means introduce | transduces the said solid standard fluorescent substance in the substantially same plane as the surface which opposes the said light detection means of this sample when detecting the fluorescence which a sample emits with the said light detector. 17. Fluorescence detector. The fluorescence detection device according to claim 10, wherein the solid standard phosphor includes a fluorescent plastic or a fluorescent glass. 20. The fluorescence detecting device according to claim 19, wherein the fluorescent plastic is fluorescent acrylic. 19. The fluorescence detecting device according to claim 10, wherein the solid standard phosphor is formed by applying a fluorescent paint on a substrate. 19. The fluorescence detection device according to claim 10, wherein the solid standard phosphor is formed by attaching a sheet member coated with a fluorescent paint or a fluorescent sheet member on a substrate. 23. The fluorescence detecting device according to claim 19, wherein the solid standard phosphor is further provided with a dimming unit. 24. The fluorescence detecting device according to claim 10, wherein the solid standard phosphor has a plate shape. The linear alkylbenzene sulfonic acid salt concentration, BOD or oil-in-water concentration of the sample is measured based on the output of the photodetector when detecting the fluorescence emitted from the sample, any one of claims 10 to 24. Item 7. The fluorescence detection device according to Item 1.

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