Fluorescence analysis cell, fluorescence analysis device, fluorescence analysis method, and method for manufacturing cell to be subjected to analysis

Abstract

Provided is a fluorescence analysis cell 10 for use in fluorescence analysis on a liquid X of interest, the fluorescence analysis cell 10 comprising a pair of translucent portions 11a, 11b opposed to each other with an internal space containing the liquid X of interest therebetween and a spacer portion 12 provided to surround the internal space so that the distance between opposed surfaces 111a, 111b of the pair of translucent portions 11a, 11b is 500 nm to 1 mm inclusive.

Description

Fluorescence analysis cell, fluorescence analysis device, fluorescence analysis method, and method for manufacturing analysis target cell

[0001] The present invention relates to a fluorescence analysis cell, a fluorescence analysis device, a fluorescence analysis method, and a method for manufacturing an analysis target cell.

[0002] A fluorescence analyzer is a device that analyzes substances contained in a test liquid by detecting the fluorescence of the test liquid generated by irradiating the test liquid with excitation light that excites the substances in the test liquid.

[0003] As disclosed in Patent Document 1, a prismatic cell is generally used as a fluorescence analysis cell for use in a fluorescence analyzer, and contains a test liquid to be measured. When excitation light is incident on this prismatic cell, fluorescence is generated from the substances in the test liquid contained in the prismatic cell.

[0004] However, when using a prismatic cell, the fluorescence generated in the test liquid is absorbed by substances in the test liquid before reaching the surface of the prismatic cell (fluorescence reabsorption). This reabsorption of fluorescence occurs even more when the test liquid contains a large amount of substance, such as a highly concentrated test liquid. As a result, the detected fluorescence is weaker than the original fluorescence generated inside the cell, resulting in measurement errors in fluorescence analysis.

[0005] Although there is a method for correcting fluorescence intensity using absorbance, for example, in a test liquid with an absorbance of 2 or more, almost no light passes through the test liquid, making it impossible to detect absorbance and correct fluorescence intensity. Furthermore, there is also a method for diluting the test liquid and performing fluorescence analysis on the diluted test liquid, but dilution may change the properties of the substances contained in the test liquid. In this case, the fluorescence of the substances contained in the test liquid changes from that before dilution, resulting in measurement errors in the fluorescence analysis, and therefore it may not be possible to dilute the test liquid in the first place.

[0006] Japanese Patent Application Laid-Open No. 2020-148547

[0007] The present invention has been made to solve the above problems, and its main object is to reduce measurement errors caused by reabsorption of fluorescence.

[0008] That is, the fluorescence analysis cell of the present invention is a fluorescence analysis cell used for fluorescence analysis of a test liquid, and is characterized by comprising a pair of light-transmitting sections facing each other across an internal space that contains the test liquid, and a spacer section that is arranged to surround the internal space and that sets the distance between the opposing surfaces of the pair of light-transmitting sections to 500 nm or more and 1 mm or less.

[0009] With this configuration, the spacer section sets the distance between the opposing surfaces of the pair of light-transmitting sections to 500 nm or more and 1 mm or less, so the distance that fluorescence generated in the test liquid travels to reach the surface of the fluorescence analysis cell is shorter than in a rectangular cell. As a result, reabsorption of fluorescence from the test liquid can be reduced. Therefore, the effect of fluorescence reabsorption is reduced, and measurement errors caused by fluorescence reabsorption can be reduced.

[0010] Here, for example, in a test liquid with an absorbance of 2, if the distance between the opposing surfaces of a pair of light-transmitting sections is greater than 1 mm, measurement errors will occur due to reabsorption of fluorescence, so the distance between the opposing surfaces of the light-transmitting sections is set to a maximum of 1 mm. When detecting transmitted light that has passed through the fluorescence analysis cell, the transmitted light cannot be detected if the optical path length is greater than 1 mm, so the distance between the opposing surfaces is set to a maximum of 1 mm. Furthermore, the minimum distance between the opposing surfaces of a pair of light-transmitting sections is set to 500 nm, which is the technical limit for forming a spacer section.

[0011] The fluorescence analysis cell preferably includes a pair of flat-plate-shaped light-transmitting members that respectively constitute a pair of light-transmitting sections, and a spacer that is provided between the pair of light-transmitting members and that constitutes the spacer section. In this case, the fluorescence analysis cell is composed of the pair of flat-plate-shaped light-transmitting members and the spacer, so that the fluorescence analysis cell can be manufactured with a simple structure.

[0012] Furthermore, it is preferable that the fluorescence analysis cell further includes a clamping member that sandwiches and fixes the pair of light-transmitting members. With this configuration, the clamping member sandwiches and fixes the pair of light-transmitting members, thereby fixing the distance between the opposing surfaces of the pair of light-transmitting members. Therefore, the optical path length of the incident excitation light is constant, allowing for accurate detection of fluorescence from the test liquid excited by the excitation light. The cell mounting section on which the fluorescence analysis cell is mounted typically has a fixing section that fixes the fluorescence analysis cell. When the fluorescence analysis cell is mounted on the fixing section of the cell mounting section, the clamping member sandwiches and fixes the pair of light-transmitting members, preventing the pair of light-transmitting members from shifting and causing the test liquid to leak out of the cell. Furthermore, when performing fluorescence analysis after mounting the fluorescence analysis cell on the cell mounting section, the clamping member sandwiches and fixes the pair of light-transmitting members, preventing the test liquid from leaking out of the cell and reducing measurement errors in fluorescence analysis.

[0013] Furthermore, the light-transmitting portion is preferably made of quartz glass, which allows the sample liquid to be analyzed, the sample liquid emitting or absorbing light in the ultraviolet region.

[0014] The effect of the fluorescence analysis cell becomes even more pronounced when the fluorescence analysis cell contains a test liquid having an absorbance of 2 or more.

[0015] Furthermore, a fluorescence analyzing device using the fluorescence analysis cell preferably includes an excitation light irradiation unit that condenses and irradiates excitation light toward the fluorescence analysis cell, and a cell installation unit that installs the fluorescence analysis cell so that a plane perpendicular to the surfaces of the pair of light-transmitting members on the side where the excitation light is incident is inclined with respect to the irradiation direction of the excitation light. With such a fluorescence analyzing device, the distance that fluorescence generated in the test liquid travels to reach the surface of the fluorescence analysis cell is shorter than with a rectangular cell, thereby reducing reabsorption of fluorescence from the test liquid. Furthermore, since the fluorescence analysis cell is installed so that a plane perpendicular to the surfaces of the pair of light-transmitting members on the side where the excitation light is incident is inclined with respect to the irradiation direction of the excitation light, fluorescence and transmitted light can be generated in the fluorescence analysis cell.

[0016] A fluorescence analyzer having the fluorescence analysis cell preferably includes a cell mounting section in which the fluorescence analysis cell is mounted, an excitation light irradiation section that focuses and irradiates excitation light toward the fluorescence analysis cell mounted on the cell mounting section, and an adjustment mechanism that adjusts the relative position between the focusing position of the excitation light and the position of the fluorescence analysis cell. With this configuration, the adjustment mechanism adjusts the relative position between the focusing position of the excitation light and the position of the fluorescence analysis cell, thereby aligning the focusing position of the excitation light with the position of the surface of the test liquid on the side where the excitation light is incident. As a result, more fluorescence is generated at the surface of the test liquid, making it less likely that fluorescence reabsorption will occur. This reduces measurement errors caused by fluorescence reabsorption.

[0017] The fluorescence analyzer preferably further includes a fluorescence detection unit that detects the fluorescence intensity of the fluorescence generated from the fluorescence analysis cell, a transmitted light detection unit that detects transmitted light generated by the excitation light passing through the fluorescence analysis cell, and a calculation unit that performs correction for the fluorescence intensity using absorbance determined from the transmitted light detected by the transmitted light detection unit. With this fluorescence analyzer, the distance between the opposing surfaces of the pair of light-transmitting units of the fluorescence analysis cell is 500 nm or more and 1 mm or less, so that it is possible to detect the fluorescence generated in the fluorescence analysis cell by the excitation light incident on the fluorescence analysis cell and the transmitted light that has passed through the fluorescence analysis cell. Furthermore, since the absorbance is calculated from the transmitted light and the fluorescence intensity is corrected using the absorbance, correction is possible even when the concentration of the test solution is high.

[0018] In the fluorescence analyzer, the fluorescence analysis cell is preferably a flow cell having an inlet portion for introducing the test liquid into the internal space and an outlet portion for discharging the test liquid from the internal space. With this configuration, the fluorescence analysis cell is a flow cell having an inlet portion and an outlet portion, so that the test liquid can be continuously or intermittently flowed through the fluorescence analysis cell. As a result, it is not necessary to prepare a batch-type cell in which the test liquid is placed in the fluorescence analysis cell for each analysis and fluorescence analysis is performed.

[0019] The analytical method of the present invention is characterized by using the above-described fluorescence analysis cell. This analytical method allows a test liquid to be contained in an internal space formed by a pair of light-transmitting sections and a spacer section with a distance between the opposing surfaces of the pair of light-transmitting sections of 500 nm to 1 mm. Therefore, the distance that fluorescence generated inside the cell travels to the cell surface is shorter than in the case of a rectangular cell. As a result, reabsorption of fluorescence in the test liquid can be reduced, thereby reducing measurement errors due to fluorescence reabsorption without diluting the test liquid or correcting the fluorescence intensity.

[0020] A method for fabricating an analysis cell for fluorescence analysis includes sandwiching a test liquid positioned inside an annular spacer having a thickness of 500 nm to 1 mm between a pair of light-transmitting members. This fabrication method allows the test liquid to be contained in the internal space formed by the spacer, with the distance between the opposing surfaces of the pair of light-transmitting members being 500 nm to 1 mm, and the pair of light-transmitting members, thereby reducing reabsorption of fluorescence generated inside the cell.

[0021] According to the present invention as described above, it is possible to reduce measurement errors caused by reabsorption of fluorescence without diluting the test liquid or correcting the fluorescence intensity.

[0022] FIG. 1 is an overall schematic diagram of a fluorescence analysis device having a fluorescence analysis cell according to the present embodiment. FIG. 2 is a perspective view of the fluorescence analysis cell according to the same embodiment. FIG. 3 is a cross-sectional view of the fluorescence analysis cell according to the same embodiment, taken along the line AA'. FIG. 4 is a manufacturing method for the fluorescence analysis cell according to the same embodiment. FIG. 5 is a cross-sectional view of a cell mounting portion according to a modified embodiment, taken along the line AA'. FIG. 6 is a perspective view of the fluorescence analysis cell according to the modified embodiment. FIG. 7 is a cross-sectional view of the fluorescence analysis cell according to the modified embodiment, taken along the line AA'. FIG. 8 is a cross-sectional view of the fluorescence analysis cell according to the modified embodiment, taken along the line AA'. FIG. 9 is a cross-sectional view of the fluorescence analysis cell according to the modified embodiment, taken along the line AA'.

[0023] A fluorescence analyzer according to one embodiment of the present invention will be described below with reference to the drawings. Note that, for ease of understanding, all of the drawings shown below are drawn in a schematic manner, with appropriate omissions or exaggerations. Identical components are designated by the same reference numerals, and their description will be omitted where appropriate.

[0024] 1, the fluorescence analyzing device 100 of this embodiment analyzes substances contained in the test liquid X by detecting fluorescence emitted by the substances contained in the test liquid X. The test liquid X has, for example, an absorbance of 2 or more, and specific examples of the test liquid X include bio-products (e.g., culture solutions or media for cells or microorganisms, liquids containing biological materials or metabolic products, etc.), beverages (e.g., fruit juice, fruit juice drinks, beverages containing coloring agents, coffee, sake, beer, etc.), foods (e.g., jelly, health foods, seasonings, etc.), oils, electrolyte solutions, etc.

[0025] Specifically, the fluorescence analyzing apparatus 100 of this embodiment comprises a fluorescence analysis cell 10 that contains a test liquid X, a cell installation section 20 in which the fluorescence analysis cell 10 is installed, an excitation light irradiation section 30 that irradiates excitation light L1 having a wavelength that excites a substance contained in the test liquid X, a fluorescence measurement section 40 that measures fluorescence L2 generated in the test liquid X, a transmitted light detection section 50 that detects transmitted light L3, which is excitation light that has passed through the fluorescence analysis cell 10, a calculation section 60 that performs calculations using signals of the fluorescence L2 detected by the fluorescence measurement section 40 and signals of the transmitted light L3 detected by the transmitted light detection section 50, and an output section 70 that outputs the results of calculations by the calculation section 60.

[0026] The fluorescence analysis cell 10 contains a test liquid X that is the subject of fluorescence analysis. The cell length of the fluorescence analysis cell 10 that contains the test liquid X is set to a distance of 500 nm to 1 mm, so that, as shown in Fig. 1, excitation light L1 incident on the fluorescence analysis cell 10 becomes fluorescence L2 and also passes through the fluorescence analysis cell 10 to become transmitted light L3. A more detailed configuration will be described later.

[0027] The cell setting section 20 is where the fluorescence analysis cell 10 is set. Specifically, as shown in Fig. 2 , the cell setting section 20 includes a main body setting section 21 on which the fluorescence analysis cell 10 is set in an upright position, and a cell pressing section 22 that is movably provided relative to the main body setting section 21 and presses and fixes the fluorescence analysis cell 10 against the main body setting section 21. The main body setting section 21 has a transmitted light passing section 211 through which the transmitted light L3 passes in order to guide the transmitted light L3 to the transmitted light detection section 50. The transmitted light passing section 211 is, for example, an opening formed in the main body setting section 21, as shown in Fig. 2 .

[0028] Furthermore, the cell mounting unit 20 mounts the fluorescence analysis cell 10 so that a plane perpendicular to the surfaces of the pair of light-transmitting members 110a, 110b on the side where the excitation light L1 is incident is inclined with respect to the irradiation direction of the excitation light L1. In other words, the cell mounting unit 20 positions the fluorescence analysis cell 10 so that a plane perpendicular to the surface of the light-transmitting portion 11a is inclined with respect to the irradiation direction of the excitation light L1. In particular, in this embodiment, as shown in FIG. 1 , the cell mounting unit 20 positions the fluorescence analysis cell 10 so that the angle between the surface of the light-transmitting portion 11a on which the excitation light L1 is incident and the incident direction of the excitation light L1 is 30 degrees or more and 45 degrees or less. Since the cell mounting unit 20 positions the fluorescence analysis cell 10 in this manner, when the excitation light L1 is incident on the fluorescence analysis cell 10, fluorescence L2 and transmitted light L3 are generated from the fluorescence analysis cell 10.

[0029] The excitation light irradiation unit 30 irradiates the test liquid X with excitation light L1 having a wavelength that excites the test liquid X, and includes an excitation light source 31 such as a xenon lamp, a spectroscope 32 that separates the light from the excitation light source 31, and an optical focusing system 33 that focuses the excitation light L1 having a specific wavelength. The excitation light L1 focused by the optical focusing system 33 enters the fluorescence analysis cell 10.

[0030] The fluorescence measurement unit 40 detects fluorescence L2 generated in the test liquid X and transmitted through the fluorescence analysis cell 10. The fluorescence measurement unit 40 includes a detection-side spectroscope 41 that separates the fluorescence L2 from the test liquid X irradiated with excitation light L1, and a fluorescence detection unit 42 that detects the separated fluorescence L2. The fluorescence detection unit 42 further calculates a fluorescence intensity that indicates the intensity of the fluorescence L2 based on the detected fluorescence L2. A specific example of the fluorescence detection unit 42 is a CCD detector that detects fluorescence having a wavelength band of 250 nm or more and 620 nm or less, and is capable of detecting fluorescence in the ultraviolet region with a wavelength of 380 nm or less.

[0031] The transmitted light detection unit 50 detects the transmitted light L3. The detector (not shown) in the transmitted light detection unit 50 is, for example, a silicon photodiode that detects wavelengths of 230 nm or more and 800 nm or less. Since the fluorescence analysis cell 10 in this embodiment has a cell length of 500 nm or more and 1 mm or less, the transmitted light L3 passes through the fluorescence analysis cell 10, and the detector in the transmitted light detection unit 50 detects the transmitted light L3.

[0032] The calculation unit 60 performs calculations using the fluorescence intensity detected by the fluorescence detection unit 42 and the transmitted light L3 detected by the transmitted light detection unit 50 to analyze the properties of the substances contained in the test liquid X. Specifically, the calculation unit 60 is a calculation device equipped with a CPU, an A / D converter, etc., and converts the detected fluorescence intensity and transmitted light L3 using the A / D converter and performs calculations using the CPU to calculate the properties of the substances contained in the test liquid X, for example, the concentration of the test liquid X and the absorbance indicating the intensity of the transmitted light L3 relative to the excitation light L1.

[0033] Furthermore, the calculation unit 60 corrects the fluorescence intensity using the calculated absorbance. In this embodiment, the test liquid X has an absorbance of 2 or more. Therefore, when the test liquid X is irradiated with excitation light L1 having a short wavelength, such as 400 nm or less, due to the reabsorption of fluorescence by absorbing components in the test liquid X (the inner filter effect), the detected fluorescence intensity may be lower than the actual fluorescence intensity. To correct this fluorescence intensity, the calculation unit 60 performs, for example, IFE correction. Note that, when the test liquid is highly concentrated, IFE correction refers to correcting the fluorescence intensity by taking into account the reabsorption of fluorescence by absorbing components in the test liquid (the inner filter effect). Furthermore, the correction performed on the fluorescence intensity using the absorbance is not limited to IFE correction and may be other corrections.

[0034] The specific details of the IFE correction are described below. The calculation unit 60 calculates the influence of the inner filter effect from the absorbance calculated by the calculation unit 60. The calculation unit 60 then calculates the fluorescence intensity taking into account the influence of the inner filter effect, thereby correcting the detected fluorescence intensity to the actual fluorescence intensity.

[0035] The output unit 70 outputs data relating to the properties of the substance analyzed by the calculation unit 60, and the output data is displayed on a display, for example.

[0036] <Specific Configuration of Fluorescence Analysis Cell> The fluorescence analysis cell 10 contains the test liquid X and is used for fluorescence analysis. Specifically, as shown in Fig. 3, the fluorescence analysis cell 10 includes a pair of flat light-transmitting members 110a, 110b that respectively constitute the pair of light-transmitting portions 11a, 11b, and a spacer 120 that is provided between the pair of light-transmitting members 110a, 110b and that constitutes the spacer portion 12 having a thickness of 500 nm to 1 mm. Furthermore, the thickness of the spacer portion 12 is preferably in the range of 1 µm to 500 µm, more preferably in the range of 1 µm to 10 µm, so that transmitted light L3 can be transmitted through the fluorescence analysis cell 10 and detected.

[0037] The pair of light-transmitting members 110a, 110b have, for example, a rectangular shape, and constitute a pair of light-transmitting sections 11a, 11b that transmit the excitation light L1 emitted from the excitation light irradiation unit 30. The pair of light-transmitting members 110a, 110b are made of a material that transmits the excitation light L1 and the fluorescence L2, such as quartz glass.

[0038] 2 and 3, the light-transmitting member 110a is disposed on the excitation light irradiation unit 30 side, and the fluorescence L2 is emitted from the light-transmitting portion 11a constituting the light-transmitting member 110a. The light-transmitting member 110b is disposed on the transmitted light detection unit 50 side, and the transmitted light L3 is emitted from the light-transmitting portion 11b constituting the light-transmitting member 110b.

[0039] The spacer 120 is annular, and in this embodiment, has a rectangular frame shape. The spacer 120 constitutes the spacer portion 12 that defines the distance between the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b. The material of the spacer 120 is corrosion-resistant to the test liquid X and does not generate impurities in the test liquid X, and is formed from stainless steel, for example. The shape of the spacer is not limited to a rectangular frame, and may be any hollow shape, such as a circular frame.

[0040] 2 and 3, the spacer 120 is provided in contact with the pair of light-transmitting members 110a, 110b. As a result, the spacer 120 makes the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b parallel to each other and sets the distance between these opposing surfaces 111a, 111b to a predetermined distance (e.g., 500 nm to 1 mm). In this way, the pair of light-transmitting members 110a, 110b respectively constitute the pair of light-transmitting portions 11a, 11b inside the spacer 120.

[0041] Furthermore, the spacer portion 12 and the pair of light-transmitting portions 11a, 11b form an internal space for accommodating the test liquid X. Specifically, as shown in Fig. 3, a spacer 120 is provided between the pair of light-transmitting members 110a, 110b, so that the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b and the inner peripheral surface 12a of the spacer portion 12 form an internal space for accommodating the test liquid X. The fluorescence analysis cell 10 becomes an analysis cell S, which is the target of fluorescence analysis, by accommodating the test liquid X in this internal space.

[0042] <Method of Preparing Analysis Cell S> Next, a method of preparing the analysis cell S in which the sample liquid X is sealed and subjected to fluorescence analysis will be described with reference to FIG.

[0043] An annular spacer 120 having a thickness of 500 nm to 1 mm is provided on the surface of one of the pair of light-transmitting members 110 a, 110 b, for example, the surface that will become the opposing surface 111 a of the light-transmitting member 110 a (see FIG. 4A ), thereby forming a space surrounded by the surface that will become the opposing surface 111 a of the light-transmitting member 110 a and the inner peripheral surface 12 a of the annular spacer 120.

[0044] The test liquid X is contained in a space formed by the opposing surface 111a of the light-transmitting member 110a and the inner peripheral surface 12a of the spacer 120 (see FIG. 4(b)).

[0045] The other light-transmitting member 110b is placed on the upper surface of the spacer 120 so as to cover the test liquid X (see FIG. 4(c)). As a result, the test liquid X is sealed in the internal space formed by the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b formed by the pair of light-transmitting members 110a, 110b and the inner peripheral surface 12a of the spacer portion 12 formed by the spacer 120. As a result, an analysis target cell S is produced (see FIG. 4(d)).

[0046] The analysis target cell S prepared by this method is placed upright on the main body placing part 21 of the cell setting part 20, as shown in Figure 2, and is pressed and fixed against the main body placing part 21 by the cell pressing part 22.

[0047] Effect of the Present Embodiment According to the fluorescence analyzer 100 of the present embodiment, the test liquid X is contained in the internal space formed by the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b and the inner peripheral surface 12a of the spacer portion 12 in the fluorescence analysis cell 10. Because the spacer portion 12 has a distance between the opposing surfaces 111a, 111b of 500 nm or more and 1 mm or less, the distance that fluorescence generated in the test liquid X travels to the surface of the fluorescence analysis cell 10 is shorter than that of a rectangular cell. As a result, reabsorption of fluorescence from the test liquid X generated inside the cell can be reduced. Therefore, since reabsorption of fluorescence from the test liquid X is reduced, measurement errors caused by reabsorption of fluorescence can be reduced. The present invention is particularly effective when the physical properties of the test liquid X are affected by dilution, for example, when the physical properties of the test liquid X are affected by changes in the coordination of solvents or coexisting solutes.

[0048] Other Modified Embodiments The present invention is not limited to the above-described embodiments.

[0049] The fluorescence analyzer 100 may further include an adjustment mechanism 23 that adjusts the relative position between the focusing position of the excitation light L1 and the position of the fluorescence analysis cell 10. For example, as shown in FIG. 5B, an adjustment spacer 231 having a thickness that aligns the focusing position of the excitation light L1 with the surface position of the test liquid X can be provided between the main body mounting portion 21 and the fluorescence analysis cell 10. Compared to the case shown in FIG. 5A, the light-transmitting member 110a moves in the direction of incidence of the excitation light L1 according to the thickness of the adjustment spacer 231, thereby aligning the focusing position of the excitation light L1 with the surface position of the test liquid X. As a result, the excitation light L1 is focused on the surface of the test liquid X, which generates more fluorescence on the surface of the test liquid X and reduces the likelihood of fluorescence reabsorption. This reduces measurement errors caused by fluorescence reabsorption.

[0050] Although the adjustment mechanism 23 is provided with an adjustment spacer 231 having a thickness that aligns the focusing position of the excitation light L1 with the surface position of the test liquid X, the adjustment mechanism 23 is not limited to this adjustment spacer 231. For example, the adjustment mechanism 23 may be an adjustment mechanism 23 that adjusts the relative position by moving the cell mounting unit 20 itself with respect to the incident direction of the excitation light L1. Furthermore, the adjustment mechanism 23 may adjust the relative position by moving the focusing position of the excitation light L1 of the excitation light irradiation unit 30.

[0051] 6, the fluorescence analysis cell 10 may further include a clamping member 13 that clamps and fixes the pair of light-transmitting members 110a, 110b. In this case, the distance between the opposing surfaces of the pair of light-transmitting members 11a, 11b is fixed, and therefore the optical path length of the excitation light L1 is also fixed. As a result, it is possible to reduce measurement errors in fluorescence caused by the excitation light L1 exciting a substance in the test liquid X.

[0052] The clamping members 13 clamp and fix the pair of light-transmitting members 110a, 110b, thereby preventing the pair of light-transmitting members 110a, 110b from shifting, which would otherwise cause the test liquid X to leak out of the fluorescence analysis cell 10. Furthermore, because the clamping members 13 can prevent the pair of light-transmitting members 110a, 110b from shifting, the work from producing the fluorescence analysis cell 10 to installing the fluorescence analysis cell 10 in the cell installation part 20 can be performed more easily.

[0053] Furthermore, in the above embodiment, the spacer 120 constitutes the spacer portion 12 having a thickness of 500 nm to 1 mm, but the thickness of the spacer 120 is not limited to this. In this case, as shown in Fig. 7 , the thickness of the light-transmitting member around the pair of light-transmitting portions 11a, 11b may be reduced and the thickness of the spacer 120 may be increased so that the distance between the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b is 500 nm to 1 mm.

[0054] The fluorescence analysis cell 10 may also be configured such that the spacer portion 12 is integrally formed in at least one of the pair of light-transmitting members 110a, 110b. In this case, as shown in Fig. 8, for example, the spacer portion 12 may be integrally formed in one of the pair of light-transmitting members, the light-transmitting member 110a, such that the distance between the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b is 500 nm or more and 1 mm or less. With this configuration, the fluorescence analysis cell 10 can be provided with the spacer portion 12 without providing the spacer 120. Note that both of the pair of light-transmitting members 110a, 110b may be configured to have protrusions that form the spacer portion 12.

[0055] Furthermore, in the above embodiment, the fluorescence analysis cell 10 is configured as a batch cell in which the test liquid X is placed in the fluorescence analysis cell 10 and fluorescence analyzed for each analysis, but it may also be configured as a flow cell in which the test liquid X is introduced into and discharged from the fluorescence analysis cell 10. That is, as shown in Fig. 9, the fluorescence analysis cell 10 may be configured to include an inlet 14 for introducing the test liquid X into the internal space and an outlet 15 for discharging the test liquid X from the internal space. In this case, the fluorescence analyzer 100 can perform fluorescence analysis by continuously or intermittently circulating the test liquid X through the fluorescence analysis cell 10.

[0056] Furthermore, in the above embodiment, the distance between the opposing surfaces 111a, 111b of the pair of light-transmitting portions 11a, 11b is constant, but the distance between the opposing surfaces may be variable. That is, as shown in Fig. 10, one of the opposing surfaces 111a may be configured as a stepped surface 114, for example, in a stepped shape, thereby enabling the distance between the opposing surfaces to be varied. As a result, there are multiple distances between the opposing surfaces, which are the optical path lengths of the excitation light L1, and therefore it is possible to measure the absorbance of the test liquid X for multiple optical path lengths in a single measurement.

[0057] In the above embodiment, the fluorescence analyzer 100 is configured to include the transmitted light detection unit 50, but it is not necessary to include the transmitted light detection unit 50. In this case, the fluorescence analyzer 100 can perform fluorescence analysis without the need to measure absorbance.

[0058] Furthermore, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0059] According to the present invention, it is possible to reduce measurement errors caused by reabsorption of fluorescence.

[0060] REFERENCE SIGNS LIST 100: Fluorescence analysis device 10: Fluorescence analysis cell 11: Light-transmitting section 12: Spacer section 20: Cell mounting section 30: Excitation light irradiation section 40: Fluorescence measurement section 50: Transmitted light detection section 60: Calculation section 70: Output section

Claims

1. A fluorescence analysis cell used in fluorescence analysis of a test liquid, comprising: a pair of light transmitting sections opposed to each other across an internal space for accommodating the test liquid; a spacer portion provided to surround the internal space and having a distance between opposing surfaces of the pair of light transmitting portions that is 500 nm or more and 1 mm or less; A fluorescence analysis cell comprising:

2. A pair of flat light-transmitting members constituting the pair of light-transmitting portions, respectively; a spacer provided between the pair of light-transmitting members and constituting the spacer portion; The fluorescence analysis cell according to claim 1 , comprising:

3. 3. The fluorescence analysis cell according to claim 2, further comprising a clamping member for clamping and fixing the pair of light-transmitting members.

4. 4. The fluorescence analysis cell according to claim 1, wherein the light transmitting portion is made of quartz glass.

5. 4. The fluorescence analysis cell according to claim 1, wherein the sample liquid has an absorbance of 2 or more.

6. A fluorescence analyzing device comprising the fluorescence analyzing cell according to any one of claims 1 to 3.

7. an excitation light irradiating unit that condenses and irradiates excitation light toward the fluorescence analysis cell; 7. The fluorescence analyzing device according to claim 6, further comprising a cell setting section for setting the fluorescence analysis cell such that a plane perpendicular to a surface of the pair of light-transmitting members on a side where the excitation light is incident is inclined with respect to an irradiation direction of the excitation light.

8. A fluorescence analysis device as described in claim 6, further comprising an adjustment mechanism for adjusting the relative position between the focusing position of the excitation light and the position of the fluorescence analysis cell.

9. A fluorescence detection unit that detects fluorescence generated in the fluorescence analysis cell by irradiating it with excitation light; a transmitted light detection unit that detects transmitted light generated by the excitation light passing through the fluorescence analysis cell; 8. The fluorescence analyzer according to claim 7, further comprising a calculation unit that performs correction for the intensity of the fluorescence detected by the fluorescence detection unit, using the absorbance determined from the transmitted light.

10. 7. The fluorescence analysis device according to claim 6, wherein the fluorescence analysis cell is a flow cell including an inlet portion for introducing the test liquid into the internal space and an outlet portion for discharging the test liquid from the internal space.

11. A fluorescence analysis method using the fluorescence analysis cell according to any one of claims 1 to 3.

12. A method for manufacturing an analysis cell to be subjected to fluorescence analysis, comprising the steps of: A method for manufacturing the analysis cell, comprising sandwiching an annular spacer having a thickness of 500 nm to 1 mm and a sample liquid located inside the spacer between a pair of light-transmitting members.