JP5324346B2 - Measuring apparatus and measuring method - Google Patents

Description

  The present invention relates to a measuring apparatus and a measuring method for measuring antioxidant properties such as juice and edible oil.

  The qualitative and quantitative determination of a chemical substance or the like can be performed by measuring the relative absorption light intensity with respect to a reference color for a sample to be measured that has undergone color development. Such a relative absorbance measurement apparatus includes, for example, a measurement cell in which a sample to be measured is arranged, a light emitting unit that irradiates the sample to be measured with monochromatic light, and transmitted light that is irradiated from the light emitting unit and passes through the sample to be measured. A light receiving portion for receiving light. In such a measuring apparatus, the relative absorbance is calculated by measuring the amount of transmitted light of each sample to which the reference solution and the reagent are added. Alternatively, the measuring device is provided with light emitting portions having two different wavelengths, and the amount of transmitted light when each of the two wavelengths is irradiated to one measured sample is measured, and the light amount measured at one wavelength is used as the reference light. Absorbance is calculated (see, for example, Patent Document 1).

JP 2007-271437 A (paragraphs [0024], [0028], [0030], [0031], FIGS. 5 and 6)

  However, in the measurement using the above-described measurement apparatus, the measurement result may be changed depending on the amount of reagent, for example. In particular, when measuring in a place that does not allow accurate measurement of reagents and samples, such as in laboratories, the result may vary from measurement to measurement even for the same measurement object, so it is stable and accurate. Measurement cannot be performed.

  In view of the circumstances as described above, an object of the present invention is to provide a measuring apparatus and a measuring method capable of performing stable measurement.

  A measuring apparatus according to an aspect of the present invention includes a first irradiation unit, a second irradiation unit, a first light receiving unit, a second light receiving unit, a third irradiation unit, a fourth irradiation unit, and a third light receiving unit. Part, a 4th light-receiving part, and a calculating part. The first irradiation unit irradiates light having a first wavelength to a first container containing a mixture of a sample and a reagent. The second irradiation unit irradiates the first container with light having a second wavelength. The first light receiving unit is disposed to face the first irradiation unit via the first container, and receives light irradiated from the first irradiation unit and transmitted through the first container. The second light receiving unit is disposed to face the second irradiation unit via the first container, and receives light irradiated from the second irradiation unit and transmitted through the first container. The third irradiation unit irradiates light having the first wavelength with respect to a second container containing a sample of the same type as the sample. The fourth irradiation unit irradiates the second container with light having the second wavelength. The third light receiving unit is disposed opposite to the third irradiation unit via the second container, and receives light irradiated from the third irradiation unit and transmitted through the second container. The fourth light receiving unit is disposed to face the fourth irradiation unit via the second container, and receives light irradiated from the fourth irradiation unit and transmitted through the second container. The calculation unit calculates the absorbance of the sample by adding the reagent based on the amount of light received by the first light receiving unit, the second light receiving unit, the third light receiving unit, and the fourth light receiving unit. Calculate the change.

  A measuring apparatus according to another aspect of the present invention includes a first irradiation unit, a second irradiation unit, a first light receiving unit, a third irradiation unit, a fourth irradiation unit, a second light receiving unit, and a calculation unit. It comprises. The first irradiation unit irradiates light having a first wavelength to a first container containing a mixture of a sample and a reagent. The second irradiation unit irradiates the first container with light having a second wavelength. The first light receiving unit is disposed to face the first irradiation unit and the second irradiation unit via the first container, and the light irradiated from the first irradiation unit and transmitted through the first container and the second irradiation. Receiving the light emitted from the section and transmitted through the first container. A 3rd irradiation part irradiates the light which has the said 1st wavelength with respect to the 2nd container which accommodates the sample of the same kind as the said sample. The fourth irradiation unit irradiates the second container with light having the second wavelength. The second light receiving unit is disposed opposite to the third irradiation unit and the fourth irradiation unit above the second container, and the light irradiated from the third irradiation unit and transmitted through the second container and the fourth irradiation The light irradiated from the part and transmitted through the second container is received. The calculation unit calculates a change in absorbance of the sample due to the addition of the reagent based on the amount of light received by the first light receiving unit and the second light receiving unit.

  In the measurement method according to another aspect of the present invention, light having a first wavelength is irradiated to a first container that contains a mixture of a sample and a reagent, and the light having the first wavelength transmitted through the first container is irradiated. Measuring the first light quantity signal in the received first light receiving section. Irradiating the first container containing the mixture with light having a second wavelength, and measuring a second light quantity signal in the second light receiving unit that has received the light having the second wavelength transmitted through the first container. . A third light quantity in a third light receiving unit that irradiates light having a first wavelength to a second container that contains a sample of the same type as the sample and receives light having the first wavelength that has passed through the second container. Measure the signal. The fourth light receiving unit receives the light having the second wavelength by irradiating the second container containing the sample of the same type as the sample and receiving the light having the second wavelength transmitted through the second container. Measure the light intensity signal. The ratio of the first light quantity signal and the second light quantity signal is logarithmically converted to calculate the absorbance of the mixture. The ratio of the third light quantity signal and the fourth light quantity signal is logarithmically converted to calculate the absorbance of the sample. From the difference between the absorbance of the mixture and the absorbance of the sample, the change in absorbance due to the addition of the reagent of the sample is calculated.

It is a top view of the antioxidant measuring device of one embodiment concerning the present invention. It is a partial enlarged plan view of the antioxidant value measuring apparatus of FIG. It is a partial schematic sectional drawing of the antioxidant value measuring apparatus of FIG. It is a figure which shows the optical path at the time of the measurement in the antioxidant value measuring apparatus of FIG. It is a circuit diagram of the control part of the antioxidant value measuring apparatus of FIG. It is a schematic sectional drawing which shows the positional relationship of the irradiation part in another embodiment, a container, and a light-receiving part. It is a schematic sectional drawing which shows the positional relationship of the irradiation part in another embodiment, a container, and a light-receiving part.

  The measuring device includes a first irradiation unit, a second irradiation unit, a first light receiving unit, a second light receiving unit, a third irradiation unit, a fourth irradiation unit, a third light receiving unit, and a fourth light receiving unit. And an arithmetic unit. The first irradiation unit irradiates light having a first wavelength to a first container containing a mixture of a sample and a reagent. The second irradiation unit irradiates the first container with light having a second wavelength. The first light receiving unit is disposed to face the first irradiation unit via the first container, and receives light irradiated from the first irradiation unit and transmitted through the first container. The second light receiving unit is disposed to face the second irradiation unit via the first container, and receives light irradiated from the second irradiation unit and transmitted through the first container. The third irradiation unit irradiates light having the first wavelength with respect to a second container containing a sample of the same type as the sample. The fourth irradiation unit irradiates the second container with light having the second wavelength. The third light receiving unit is disposed opposite to the third irradiation unit via the second container, and receives light irradiated from the third irradiation unit and transmitted through the second container. The fourth light receiving unit is disposed to face the fourth irradiation unit via the second container, and receives light irradiated from the fourth irradiation unit and transmitted through the second container. The calculation unit calculates the absorbance of the sample by adding the reagent based on the amount of light received by the first light receiving unit, the second light receiving unit, the third light receiving unit, and the fourth light receiving unit. Calculate the change.

  According to this measurement apparatus, the absorbance of the mixture of the sample and the reagent is calculated from the ratio of the light amount signals of the light received by the first light receiving unit and the second light receiving unit. Here, for example, the light having the first wavelength irradiated from the second irradiation unit is calculated as light having a wavelength (reference light) in a region where the transmittance does not change even when the color of the sample is changed by the reagent. The absorbance of the mixture is a value corrected so that the coloration of the sample itself is canceled. Then, by correcting the absorbance in the sample calculated from the ratio of the light quantity signals of the received light at the third light receiving unit and the fourth light receiving unit so as to be subtracted from the absorbance of the mixture, the color of the sample itself is further increased. It is corrected so as to be canceled. Therefore, the correction for canceling the coloring of the sample itself is performed twice, so that accurate measurement can be performed. For example, stable measurement can be performed even if the degree of coloring varies depending on the amount of the sample. In addition, the absorbance of the mixture of the sample and the reagent and the absorbance of the sample can be measured simultaneously with one measuring device.

  In the measurement apparatus, the light emitted from the first irradiation unit is collected by the first container and received by the first light receiving unit, and the light emitted from the second irradiation unit is the first light. Light collected by the container and received by the second light receiving unit, and irradiated from the third irradiation unit is collected by the second container and received by the third light receiving unit, and the fourth irradiation unit. The light emitted from is condensed by the second container and received by the fourth light receiving unit.

  According to this apparatus, the lens effect can be given to the first container and the second container so as to collect the transmitted light. Therefore, it is not necessary to separately provide a lens for condensing light, and the entire measuring apparatus can be reduced in size.

  In the measuring apparatus, the first container and the second container have a circular cylindrical shape or a spherical shape having an inner diameter d of 5 to 12 mm in cross section in a horizontal plane, and each of the irradiation units has a light emitting surface of 2.6 mm or less. Each light receiving part has an effective width of 5.8 mm or less, and the distance between the light emitting surface arranged opposite to each other and the light receiving surface of the light receiving part is not more than 5 times d. When a is the distance between the center of the circle and the light emitting surface corresponding to each of the circles, and b is the distance between the center and the light receiving surface corresponding to each of the circles, a = d × 1. 1 to 4.5 and b = d × 0.5 to 3.9.

  According to this apparatus, the first container and the second container have a circular cylindrical shape or a spherical shape with an outer diameter d of 5 to 12 mm in cross section, and the effective diameter of the light emitting surface of each irradiation unit is 2.6 mm or less, When the effective width of each light receiving part is 5.8 mm or less, and the design range is such that the distance between the light emitting surface arranged opposite to each other and the light receiving surface of the light receiving part is 5 times or less of d, the circular section of the container Where a is the distance between the center of the light emitting surface and the light emitting surface, and b is the distance between the center of the cross-sectional circle and the light receiving portion, a is 1.1 to 4.5 times d and b is 0.5 to 3 d By setting the ratio to 9 times, even if the container thickness or material is different, the physical properties of the sample are different, or the refractive index is different due to the wavelength of the light source, It is possible to collect light appropriately.

  In the measuring apparatus, the first wavelength is set in a wavelength region in which the transmittance of the mixture by the reagent is changed by the irradiation, and the transmittance of the mixture by the reagent is changed by the irradiation of the second wavelength. Not set in the wavelength region.

  According to this apparatus, since the second wavelength becomes light (reference light) in a region where the transmittance does not change even when the color of the sample is changed by the reagent, the first light receiving unit and the second light receiving unit. The absorbance calculated from the amount of received light is a value obtained by canceling the coloration of the sample itself.

  In the measurement unit, the calculation unit is configured to logarithmically convert the ratios of the light amount signals detected by the first light receiving unit and the second light receiving unit, respectively, and to detect the absorbance of the mixture, the third light receiving unit, and the third light receiving unit. The absorbance of the sample is calculated by logarithmically converting the ratio of the light quantity signals respectively detected by the four light receiving sections, and the change in absorbance due to the addition of the reagent of the sample is calculated from the difference between the absorbance of the mixture and the absorbance of the sample. Is calculated.

  According to this apparatus, the absorbance of the mixture corrected to cancel the coloring of the sample itself is calculated by logarithmically converting the ratio of the light amount signals detected by the first light receiving unit and the second light receiving unit, respectively. . Then, by obtaining the difference between the absorbance of the mixture and the absorbance of the sample, a change in absorbance due to addition of the reagent of the sample, which is further corrected to cancel the coloring of the sample itself, is calculated.

  The measurement apparatus includes a first optical path of light having the first wavelength from the first irradiation unit until the first light receiving unit receives the light, and the second light receiving unit irradiated from the second irradiation unit. The second optical path of the light having the second wavelength until it is received by the light is orthogonal to the light having the first wavelength that is irradiated from the third irradiation unit and received by the third light receiving unit. The first optical path is orthogonal to the fourth optical path of the light having the second wavelength that is emitted from the fourth irradiation unit and received by the fourth light receiving unit.

  According to this apparatus, the first optical path and the second optical path orthogonal to each other, the third optical path and the fourth optical path can be arranged on the same horizontal plane, for example, and the size of the measuring apparatus in the direction perpendicular to the horizontal plane can be increased. Can be small.

  The measurement apparatus includes a first optical path of light having the first wavelength from the first irradiation unit until the first light receiving unit receives the light, and the second light receiving unit irradiated from the second irradiation unit. The second optical path of the light having the second wavelength until it is received by the first light is arranged on different horizontal planes, and is irradiated from the third irradiation unit and received by the third light receiving unit. The first optical path of light having a wavelength and the fourth optical path of light having the second wavelength until the fourth light receiving section irradiated from the fourth irradiation section is received on different horizontal planes. Is done.

  According to this apparatus, since the first optical path and the second optical path are arranged on different horizontal planes, the first container 41 is irradiated even when the irradiation timings of the first irradiation unit and the second irradiation unit are simultaneously set. Therefore, the first light receiving unit and the second light receiving unit can receive light without being affected by each other's light. Accordingly, the measurement time can be shortened because the irradiation can be performed simultaneously without shifting the timing. Similarly, since the third optical path and the fourth optical path are arranged on different horizontal planes, the location where the second container 31 is irradiated even when the irradiation timings of the third irradiation section and the fourth irradiation section are simultaneously set. Therefore, the third light receiving unit and the fourth light receiving unit can receive light without being affected by each other's light. Accordingly, the measurement time can be shortened because the irradiation can be performed simultaneously without shifting the timing.

  Another measuring apparatus includes a first irradiation unit, a second irradiation unit, a first light receiving unit, a third irradiation unit, a fourth irradiation unit, a second light receiving unit, and a calculation unit. The first irradiation unit irradiates light having a first wavelength to a first container containing a mixture of a sample and a reagent. The second irradiation unit irradiates the first container with light having a second wavelength. The first light receiving unit is disposed to face the first irradiation unit and the second irradiation unit via the first container, and the light irradiated from the first irradiation unit and transmitted through the first container and the second irradiation. Receiving the light emitted from the section and transmitted through the first container. A 3rd irradiation part irradiates the light which has the said 1st wavelength with respect to the 2nd container which accommodates the sample of the same kind as the said sample. The fourth irradiation unit irradiates the second container with light having the second wavelength. The second light receiving unit is disposed opposite to the third irradiation unit and the fourth irradiation unit above the second container, and the light irradiated from the third irradiation unit and transmitted through the second container and the fourth irradiation The light irradiated from the part and transmitted through the second container is received. The calculation unit calculates a change in absorbance of the sample due to the addition of the reagent based on the amount of light received by the first light receiving unit and the second light receiving unit.

  According to this measuring apparatus, the absorbance of the mixture of the sample and the reagent is calculated from the ratio of the light quantity signals of the light irradiated from the first irradiation unit and the second irradiation unit and received by the first light receiving unit. Here, for example, the light having the first wavelength irradiated from the second irradiation unit is calculated as light having a wavelength (reference light) in a region where the transmittance does not change even when the color of the sample is changed by the reagent. The absorbance of the mixture is a value corrected so that the coloration of the sample itself is canceled. Then, by correcting the absorbance of the sample calculated from the ratio of the light amount signals of the light irradiated from the third irradiation unit and the fourth irradiation unit and received by the third light receiving unit so as to be subtracted from the absorbance of the mixture, Further, correction is performed so that coloring of the sample itself is canceled. Therefore, the correction for canceling the coloring of the sample itself is performed twice, so that accurate measurement can be performed. In addition, as compared with a case where a light receiving unit is provided for each irradiation unit, individual element differences in the light receiving unit do not affect the measurement.

  The measurement method includes irradiating light having a first wavelength to a first container containing a mixture of a sample and a reagent, and receiving light having the first wavelength transmitted through the first container. Including measuring a single light quantity signal. Irradiating the first container containing the mixture with light having a second wavelength, and measuring a second light quantity signal in the second light receiving unit that has received the light having the second wavelength transmitted through the first container. . A third light quantity in a third light receiving unit that irradiates light having a first wavelength to a second container that contains a sample of the same type as the sample and receives light having the first wavelength that has passed through the second container. Measure the signal. The fourth light receiving unit receives the light having the second wavelength by irradiating the second container containing the sample of the same type as the sample and receiving the light having the second wavelength transmitted through the second container. Measure the light intensity signal. The ratio of the first light quantity signal and the second light quantity signal is logarithmically converted to calculate the absorbance of the mixture. The ratio of the third light quantity signal and the fourth light quantity signal is logarithmically converted to calculate the absorbance of the sample. From the difference between the absorbance of the mixture and the absorbance of the sample, the change in absorbance due to the addition of the reagent of the sample is calculated.

  According to this measurement method, the absorbance of the mixture corrected to cancel the coloring of the sample itself is calculated by logarithmically converting the ratio of the first light amount signal and the second light amount signal. Then, by obtaining the difference between the absorbance of the mixture and the absorbance of the sample, a change in absorbance due to addition of the reagent of the sample, which is further corrected to cancel the coloring of the sample itself, is calculated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Configuration of Antioxidation Value Measuring Device]
FIG. 1 is a plan view of an antioxidant value measuring apparatus according to an embodiment. FIG. 2 is a partially enlarged plan view of a measuring unit constituting a part of the antioxidant value measuring apparatus of FIG. FIG. 3 is a partial schematic cross-sectional view of the measurement unit shown in FIG. 2, and is a diagram showing a positional relationship among the photodiode, the container, and the light emitting diode. The antioxidant value measuring apparatus according to the present embodiment is for measuring the antioxidant value of a beverage such as orange juice, and has a portable size of, for example, A5 size and can be measured at a desired location. is there.

  As shown in FIG. 1, the antioxidant value measuring apparatus 1 includes a main body 20 and an AC adapter 10 electrically connected to the main body 20.

  The main body 20 includes a measurement unit 21, a switch button 22 for instructing the start of measurement, a liquid crystal display 23 for displaying a measurement result, and a control unit (not shown) described later.

  As shown in FIGS. 1 and 2, the measurement unit 21 includes a first measurement unit 40 and a measurement second measurement unit 30. The first measurement unit 40 and the second measurement unit 30 have the same configuration except for the measurement object. The first measurement unit 40 measures the absorbance of the sample to which the reagent has been added, and the second measurement unit 30 measures the absorbance of the sample to which no reagent has been added. The antioxidant value measuring apparatus 1 measures the antioxidant value of a sample by utilizing the fact that the color of the sample changes due to the addition of a reagent, in other words, the absorbance at a certain wavelength changes. In the present embodiment, the antioxidant value of the sample is measured from the difference in absorbance measured by each of the first measurement unit 40 and the second measurement unit 30. As a sample to be measured, for example, a beverage such as orange juice or tea can be used, but is not limited thereto.

In the present embodiment, PAO (trade name, manufactured by Niken Senile Co., Ltd., Japan Aging Control Laboratory) was used as a reagent. PAO contains Cu ²⁺ , Cu ^+, and a coloring reagent that absorbs light at a first wavelength of 450 nm to 490 nm. In this reagent, the antioxidation property of the sample can be measured by utilizing the fact that Cu ²⁺ undergoes a reduction reaction upon addition of the sample to become Cu ⁺ and the color is changed by the coloring reagent. Thus, in addition to the reagent utilizing the copper reduction reaction, a reagent utilizing the iron reduction reaction can also be used.

  The first measuring unit 40 includes a first holding unit 48, a light emitting diode a (LEDa) 44 as a first irradiation unit, a light emitting diode b (LEDb) 45 as a second irradiation unit, and a first light receiving unit. A photodiode a (PDa) 43 and a photodiode b (PDb) 42 as a second light receiving unit are provided.

  The 1st holding | maintenance part 48 hold | maintains the 1st container 41 in which the mixture of the sample and reagent which are a measuring object is accommodated. In the first holding unit 48, a portion corresponding to the first optical path 46 from the light emitted from the light emitting diode a 44 to the first container 41 and further passing through the first container 41 and received by the photodiode a 43. Is a through hole. Similarly, the portion corresponding to the second optical path 47 from the light emitted from the light emitting diode b45 to the first container 41 and further passing through the first container 41 and received by the photodiode b42 is also a through hole. It has become. The light emitting diode a44, the light emitting diode b45, the photodiode a43, and the photodiode b42 are arranged so that the first optical path 46 and the second optical path 47 are orthogonal to each other.

  The light emitting diode a44 irradiates light having a first wavelength of 490 nm. As the first wavelength, a wavelength at which a color change due to the addition of the reagent can be detected, that is, a wavelength in a region where the transmittance measured by the addition of the reagent is changed is used, and a wavelength of 450 nm to 490 nm is used. it can. In this embodiment, a wavelength of 490 nm is adopted.

  The light emitting diode b45 emits light having a second wavelength of 625 nm. As the second wavelength, a wavelength in a region where a color change due to the addition of the reagent is not detected, that is, a wavelength in a region where the transmittance measured by the addition of the reagent does not occur is used.

  As shown in FIGS. 2 and 3, the photodiode a43 is disposed to face the light emitting diode a44 via the first container 41 held by the first holding unit 48, and is irradiated from the light emitting diode a44 to cause the first container 41 to pass through. Light having a wavelength of 490 nm that is transmitted and collected by the first container 41 is received. The photodiode b42 is disposed to face the light emitting diode b45 via the first container 41 held by the first holding unit 48, is irradiated from the light emitting diode b45, passes through the first container 41, and is condensed by the first container 41. Receiving light having a wavelength of 625 nm.

  As shown in FIG. 2, the second measuring unit 30 includes a second holding unit 38, a light emitting diode c (LEDc) 34 as a third irradiation unit, and a light emitting diode d (LEDd) 35 as a fourth irradiation unit. And a photodiode c (PDc) 33 as a third light receiving part and a photodiode d (PDd) 32 as a fourth light receiving part.

  The second holding unit 38 holds the second container 31 in which a sample that is a measurement target is stored. The sample stored in the second container 31 is the same as the sample included in the mixture stored in the first container 41. In the second holding unit 38, a portion corresponding to the third optical path 36 from the light emitted from the light emitting diode c34 to the second container 31 and further transmitted through the second container 31 and received by the photodiode c33. Is a through hole. Similarly, a portion corresponding to the fourth optical path 37 from the light emitted from the light emitting diode d35 to the second container 31 and further transmitted through the second container 31 and received by the photodiode d32 is also a through hole. It has become. The light emitting diode c34, the light emitting diode d35, the photodiode c33, and the photodiode d32 are arranged so that the third optical path 36 and the fourth optical path 37 are orthogonal to each other.

  In order to obtain the antioxidant value from the comparison between the measurement result of the first measurement unit 40 and the measurement result of the second measurement unit 30, the second measurement unit 30 calculates the absorbance of the sample by the same method as the first measurement unit 40. Therefore, the light emitting diode c34 is assumed to emit light having a first wavelength of 490 nm, and the light emitting diode d35 is assumed to emit light having a second wavelength of 625 nm.

  As shown in FIGS. 2 and 3, the photodiode c <b> 33 is disposed to face the light emitting diode c <b> 34 via the second container 31 held by the second holding unit 38, and is irradiated from the light emitting diode c <b> 34 to pass through the second container 31. Light having a wavelength of 490 nm that is transmitted and collected by the second container 31 is received. The photodiode d32 is disposed to face the light emitting diode d35 via the second container 31 held by the second holding unit 38, is irradiated from the light emitting diode d35, passes through the second container 31, and is collected by the second container 31. Receiving light having a wavelength of 625 nm.

  The first container 41 and the second container 31 are made of a transparent material such as glass or plastic.

  FIG. 4 shows the light path from the light emitting diode 35 (34, 45, 44) to the light passing through the first container 31 (second container 41) and being received by the photodiode 32 (33, 42, 43). FIG. As shown in FIG. 4, each of the first container 41 and the second container 31 has a cylindrical shape or a spherical shape having a circular cross section with an inner diameter d in the horizontal direction. In the present embodiment, the first container 41 and the second container 31 have a cylindrical shape. ing. As shown in FIG. 4, the light emitted from the light emitting diode 35 (34, 45, 44) is collected by the first container 31 (second container 41), and then the photodiode 32 (33, 42, 43). ). In this way, by providing the first container 31 and the second container 41 with a lens effect and condensing the transmitted light, the output detected by the photodiode 32 (33, 42, 43) is increased, and the accuracy is increased. It can measure well. By providing the lens effect to the container for storing the sample in this way, it is not necessary to separately provide a lens for condensing light, and the entire measuring apparatus can be reduced in size.

  In this embodiment, the circular diameter d of the cross section of the 1st container 41 and the 2nd container 31 is 5-12 mm, and the light source surface 35a (34a, 45a, 44a) of the light emitting diode 35 (34, 45, 44) which is a light source. The effective diameter of the photodiode 32 (33, 34, 45, 44), which is a light receiving element, is 5.8 mm or less, and from the light emitting surface 32a (33a, 34a, 45a, 44a) of the photodiode. The distance to the light receiving surface was 5 times the diameter d. Within this design range, as shown in FIG. 4, the distance between the circular center of the first container 41 and the second container 31 and the light emitting diode 35 (34, 45, 44) is a, and the center of the circular section And the distance between the photodiode 32 (33, 42, 43) and b are preferably 1.1 to 4.5 times d and b is 0.5 to 3.9 times d. . Thereby, within the above-mentioned design range, the thickness and material of the container (the first container 41 and the second container 31) for storing the sample are different, the physical properties of the sample are different, or the difference in refractive index due to the wavelength of the light source or the like. Even if there is, it is possible to appropriately collect light on the photodiode 32 (33, 34, 45, 44).

  Next, the control part 60 built in the antioxidant value measuring apparatus 1 is demonstrated using FIG. FIG. 5 is a diagram illustrating the control unit.

  As shown in FIG. 5, the control unit 60 includes an LED power circuit 65 to which power is supplied via the AC adapter 10, an analog power circuit 76, a digital power circuit 85, and a light emitting diode (LED) drive. A circuit a61, a light emitting diode (LED) drive circuit b62, a light emitting diode (LED) drive circuit c63, a light emitting diode (LED) drive circuit d64, a current-voltage conversion / amplification circuit a71, and a current-voltage conversion / amplification circuit b72. A current-voltage conversion / amplification circuit c73, a current-voltage conversion / amplification circuit d74, a multiplexer / AD conversion circuit 75, a CPU (Central Processing Unit) 80 as an arithmetic unit, an EEPROM 81, and an LCD drive circuit 82 The command button I / F circuit 83 and the USB-232CI / F circuit 84 are provided.

  The LED power supply circuit 65 includes a light emitting diode (LED) drive circuit a61, a light emitting diode (LED) drive circuit b62, a light emitting diode (LED) that controls lighting of the light emitting diodes a to d (reference numerals 44, 45, 34, and 35). ) It is connected to a drive circuit c63 and a light emitting diode (LED) drive circuit d64.

  The analog power supply circuit 76 includes a current-voltage conversion / amplification circuit a71, a current-voltage conversion / amplification circuit b72, a current-voltage conversion / amplification circuit c73, a current-voltage conversion / amplification circuit d74, and a multiplexer / AD conversion circuit 75. It is connected to the. The current-voltage conversion / amplification circuits a to d (71 to 74) are connected to the photodiodes a to d (reference numerals 43, 42, 33, and 32), respectively.

  The digital power supply circuit 85 is connected to the multiplexer / AD conversion circuit 75, the CPU 80, the LCD drive circuit 82, and the USB-RS232CI / F circuit 84.

  The CPU 80 serving as a calculation unit that calculates the change in absorbance due to the addition of the reagent of the sample includes LED drive circuits a to d (reference numerals 61 to 64), a multiplexer / AD conversion circuit 75, an EEPROM 81, an LCD drive circuit 82, and a command button I. / F circuit 83 and USB-232CI / F circuit 84 are connected.

  In the CPU 80, control of the lighting start time and end time of each of the light emitting diodes a to d (reference numerals 44, 45, 34, and 35) and the output result of the photodiodes a to d (reference numerals 43, 42, 33, and 32) are performed. Thus, the absorbance in each of the first measurement unit 40 and the second measurement unit 30 is calculated, and the antioxidant value is calculated from the difference in absorbance in each of the first measurement unit 40 and the second measurement unit 30.

  The current-voltage conversion / amplification circuits a to d (71 to 74) convert the current detected from the photodiodes a to d (43, 42, 33, 32) into voltage values, amplify them, and use them as light quantity signals. It is.

  The multiplexer / AD conversion circuit 75 digitally outputs the light amount signals input from the current-voltage conversion / amplification circuits a to d (71 to 74) and outputs them to the CPU 80.

  The EEPROM 81 is written with calibration curve data, light quantity signals measured by the photodiodes a to d (reference numerals 43, 42, 33, and 32), and absorbances at the first measurement unit 40 and the second measurement unit 30, respectively. It is.

  The LCD drive circuit 82 displays the calculated antioxidant value on the liquid crystal display unit (LCD) 23.

  The command button I / F circuit 83 instructs the start of measurement when the switch button 22 is pressed by the operator.

  The USB-232CI / F circuit 84 connects the main body 20 and an external device such as a personal computer via a USB terminal 86 (USB CN) provided in the main body 20 of the antioxidant value measuring apparatus 1 as necessary. It is.

[Operation Method of Antioxidation Value Measuring Device and Control Unit Operation During Operation]
Next, the operation method of the antioxidant value measuring apparatus 1 and the operation of the control unit during operation in the above-described embodiment of the present invention will be described.

  First, the first container 41 and the second container 31 are prepared. Only the first container 41 contains the reagent in advance. Next, for example, orange juice, which is a measurement object, is put in each of the first container 41 and the second container 31 as a sample. Moreover, the power supply of the antioxidant value measuring apparatus 1 is turned on.

  Next, the measurement is started by holding the first container 41 in the first holding part 48 and the second container 31 in the second holding part 38 and pressing the switch button 22.

  In the control unit 60, a measurement start instruction is given to the CPU 80 by the command button I / F circuit 84, and the timing of the lighting start time and end time of each light emitting diode is controlled by the CPU 80. First, in each of the first measurement unit 40 and the second measurement unit 30, lighting of the light emitting diode a44 and the light emitting diode c34 is started. The light having a wavelength of 490 nm emitted from each of the light emitting diode a44 and the light emitting diode c34 is irradiated to the first container 41 and the second container 31, respectively, passes through each container, and is collected by each container, and the photodiode a43. The light is received by the photodiode c33. The current detected from the photodiode a43 and the photodiode c33 by light reception is converted into a voltage value and amplified by the current-voltage conversion / amplification circuit a71 and the current-voltage conversion / amplification circuit c73, respectively, and is supplied to the multiplexer / AD conversion circuit 75. The first light amount signal and the second light amount signal are input. Each light amount signal input to the multiplexer / AD conversion circuit 75 is converted into a digital signal and output to the CPU 80. Each digitized light amount signal is written into a RAM in the CPU 80. Thereafter, the lighting of the light emitting diode a44 and the light emitting diode c34 is terminated.

  Next, in each of the first measurement unit 40 and the second measurement unit 30, lighting of the light emitting diode b45 and the light emitting diode d35 is started. Light having a wavelength of 625 nm emitted from each of the light emitting diode b45 and the light emitting diode d35 is irradiated to the first container 41 and the second container 31, passes through the container, and is collected by the container. Light is received by the diode d32. The current detected from the photodiode b42 and the photodiode d32 by light reception is converted into a voltage value and amplified by the current-voltage conversion / amplification circuit b72 and the current-voltage conversion / amplification circuit d74, respectively, and is supplied to the multiplexer / AD conversion circuit 75. The third light amount signal and the fourth light amount signal are input. Each light amount signal input to the multiplexer / AD conversion circuit 75 is converted into a digital signal and output to the CPU 80. Each digitized light amount signal is written into the internal RAM by the CPU 80. Thereafter, the lighting of the light emitting diode b45 and the light emitting diode c35 is terminated.

  Next, the CPU 80 calculates the absorbance of the mixture in the first container 41 by logarithmically converting the ratio of the first light amount signal and the third light amount signal detected by the photodiode a43 and the photodiode b42, respectively. Thereby, the light absorbency by which correction | amendment which cancels coloring of sample itself was made can be obtained. Further, the absorbance of the sample in the second container 31 is calculated by logarithmically converting the ratio of the second light amount signal and the fourth light amount signal detected by the photodiode c33 and the photodiode d32.

  Next, the CPU 80 calculates the antioxidant value of the sample from the difference between the absorbance of the mixture and the absorbance of the sample and a calibration curve written in advance in the EEPROM 81. Thus, by calculating from the difference between the absorbance of the mixture and the absorbance of the sample, correction is further performed so as to cancel the coloring of the sample itself. The calculated antioxidant value is displayed on the liquid crystal display (LCD) 23 by the LCD drive circuit 82.

  As described above, since the measurement apparatus according to the present embodiment is corrected to cancel the coloring of the sample itself twice, it can perform measurement with high accuracy. In addition, since the measuring device itself is miniaturized to be portable and can perform accurate measurements, for example, the juice that is the measurement object is sold without taking the sample back to the laboratory. In the immediate vicinity of the vending machine, it is possible to easily, stably and accurately measure the antioxidant value of the juice. In addition, an inexpensive photodiode can be used as the light receiving unit, and an inexpensive measuring device can be obtained. In addition, by using a light emitting diode that generates a small amount of heat as the irradiating unit, it is not necessary to reduce power consumption or replace it for a long time.

  The measuring device in the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the antioxidant value is obtained, but it is also possible to quantitatively measure a specific chemical substance by changing the reagent and measuring the color change caused by the reagent. In the above-described embodiment, the first optical path and the second optical path, and the third optical path and the fourth optical path are arranged orthogonally on the same horizontal plane, but the present invention is not limited to this. For example, as shown in FIG. 6, the first light emitted from the first light emitting diode 135 (third light emitting diode 235) until the first photodiode 132 (third photodiode 232) receives the light having the first wavelength. The light having the second wavelength emitted from the first optical path 137 (third optical path 237) and the second light emitting diode 134 (fourth light emitting diode 234) is received by the third photodiode 133 (fourth photodiode 233). The second optical path 136 (fourth optical path 236) may be positioned so as to be positioned in different horizontal planes, in other words, vertically positioned along a direction perpendicular to the horizontal plane. Thereby, when the mixture (or sample) in the first container 41 (or the second container 31) has a uniform concentration, the measurement at each wavelength is simultaneously performed at two different positions on one container. Can do. Therefore, the measurement time can be shortened. In FIG. 6, the first optical path 137 (third optical path 237) and the second optical path 136 (fourth optical path 236) are arranged in parallel, but may be arranged orthogonally.

  In FIG. 6, one photodiode is provided corresponding to each of the light emitting diodes having different wavelengths. However, as shown in FIG. 7, the light emitted from the light emitting diodes 135 (235) and 134 (234). May be received by a common photodiode 332 (333). In this case, the measurement using the light emitting diode 135 (235) and the measurement using the light emitting diode 134 (234) are not performed at the same time, and the measurement is performed at different timings. When such a configuration is adopted in the measurement apparatus, the first irradiation unit 135 that irradiates the first container 41 containing the mixture of the sample and the reagent with light having the first wavelength in the first measurement unit; The second irradiation unit 134 that irradiates the container 41 with light having the second wavelength, and the first irradiation unit 135 and the second irradiation unit 134 that are opposed to the first irradiation unit 135 via the first container 41, are irradiated from the first irradiation unit 135. A first light receiving unit 332 that receives the light transmitted through the first container 41 and the light irradiated from the second irradiation unit 134 and transmitted through the first container 41 is provided. The second measurement unit irradiates the second container 31 containing a sample of the same type as the sample with the third irradiation unit 235 that irradiates light having the first wavelength, and the second container 31 receives light having the second wavelength. The fourth irradiation unit 234 that irradiates, the third irradiation unit 235 and the fourth irradiation unit 234 through the second container 31, and the light that has been irradiated from the third irradiation unit 235 and transmitted through the second container 31. A second light receiving unit 333 that receives the light irradiated from the four irradiation unit 234 and transmitted through the second container 31 is provided. Then, based on the amount of light received by the first light receiving unit 332 and the second light receiving unit 333, a change in absorbance due to addition of the reagent of the sample may be calculated. Thus, in each measurement part, the number of parts can be reduced by using one light receiving part, and the cost can be reduced. Furthermore, compared with the case where a light receiving part is provided for each irradiation part, the individual difference of the light receiving part does not affect the measurement.

  In the above-described embodiment, PAO is used as a reagent. However, when another reagent is used, the first wavelength is 340 nm to 950 nm, more preferably 400 nm to 600 nm, and still more preferably 450 nm to 490 nm. Can be used.

DESCRIPTION OF SYMBOLS 1 ... Antioxidation measuring device 31 ... 2nd container 32 ... Photodiode d
32a, 33a, 34a, 45a, 44a ... Light emitting surface 33 ... Photo diode c
34 ... Light-emitting diode c
34a, 35a, 45a, 44a ... Light source surface 35 ... Light emitting diode d
36 ... 4th optical path 37 ... 3rd optical path 38 ... 2nd holding | maintenance part 41 ... 1st container 42 ... Photodiode b
43 ... Photodiode a
44. Light emitting diode a
45. Light emitting diode b
46 ... 2nd optical path 47 ... 1st optical path 48 ... 1st holding | maintenance part 80 ... CPU
132: 1st photodiode 133 ... 2nd photodiode 134 ... 2nd light emitting diode 135 ... 1st light emitting diode 136 ... 2nd optical path 137 ... 1st optical path 232 ... 3rd photodiode 233 ... 4th photodiode 234 ... 4th Light emitting diode 235... Third light emitting diode 236... Second optical path 237... First optical path 332... First photodiode 333.

Claims (7)

A first irradiation unit that irradiates light having a first wavelength to a first container containing a mixture of a sample and a reagent;
A second irradiation unit for irradiating the first container with light having a second wavelength;
A first light-receiving unit disposed opposite to the first irradiation unit via the first container and receiving light emitted from the first irradiation unit and transmitted through the first container;
A second light receiving unit that is disposed opposite to the second irradiation unit via the first container and receives light emitted from the second irradiation unit and transmitted through the first container;
A third irradiating unit that irradiates a second container containing a sample of the same type as the sample with light having the first wavelength;
A fourth irradiation unit for irradiating the second container with light having the second wavelength;
A third light receiving unit disposed opposite to the third irradiation unit via the second container and receiving the light irradiated from the third irradiation unit and transmitted through the second container;
A fourth light-receiving unit that is disposed opposite to the fourth irradiation unit via the second container, receives light emitted from the fourth irradiation unit and transmitted through the second container;
An operation for calculating a change in absorbance of the sample due to the addition of the reagent based on the amount of light received by the first light receiving unit, the second light receiving unit, the third light receiving unit, and the fourth light receiving unit. ; and a part,
The first wavelength is set to a wavelength region in which the transmittance of the mixture by the reagent is changed by the irradiation,
The second wavelength is set in a wavelength region where the transmittance of the mixture by the reagent does not change by the irradiation,
In the calculation unit, the absorbance of the mixture is logarithmically converted by the ratio of the light amount signals detected by the first light receiving unit and the second light receiving unit, respectively, and the third light receiving unit and the fourth light receiving unit respectively. Measurement in which the absorbance of the sample is calculated by logarithmically converting the ratio of the detected light quantity signal, and the change in absorbance due to the addition of the reagent of the sample is calculated from the difference between the absorbance of the mixture and the absorbance of the sample apparatus. The measuring device according to claim 1,
The light emitted from the first irradiation unit is collected by the first container and received by the first light receiving unit,
The light emitted from the second irradiation unit is collected by the first container and received by the second light receiving unit,
The light emitted from the third irradiation unit is collected by the second container and received by the third light receiving unit,
The light emitted from the fourth irradiation unit is collected by the second container and received by the fourth light receiving unit. The measuring device according to claim 2,
The first container and the second container have a circular cylindrical shape or a spherical shape with an outer diameter d having a cross-sectional shape of 5 to 12 mm in a horizontal plane,
Each of the irradiation sections has an effective diameter of a light emitting surface of 2.6 mm or less,
Each of the light receiving portions has an effective width of 5.8 mm or less,
The distance between the light-emitting surface and the light-receiving surface of the light-receiving unit that are arranged to face each other is 5 times or less of d,
When the distance between the center of the circle and the light emitting surface corresponding to each of the circles is a, and the distance between the center and the light receiving surface corresponding to each of the circles is b,
A measuring device in which a = d × 1.1 to 4.5 and b = d × 0.5 to 3.9. The measuring device according to claim 1 ,
A first optical path of light having the first wavelength until it is irradiated from the first irradiation unit and received by the first light receiving unit, and until it is irradiated from the second irradiation unit and received by the second light receiving unit Is orthogonal to the second optical path of the light having the second wavelength,
A third optical path of the light having the first wavelength until it is irradiated from the third irradiation unit and received by the third light receiving unit, and until it is irradiated from the fourth irradiation unit and received by the fourth light receiving unit A measuring device orthogonal to the fourth optical path of the light having the second wavelength. The measuring device according to claim 4 ,
A first optical path of light having the first wavelength until it is irradiated from the first irradiation unit and received by the first light receiving unit, and until it is irradiated from the second irradiation unit and received by the second light receiving unit The second optical path of the light having the second wavelength is disposed on different horizontal planes,
The light is received by the third light path of the light having the first wavelength from the third irradiation unit until it is received by the third light receiving unit and the fourth light receiving unit irradiated by the fourth irradiation unit. The measuring apparatus arrange | positioned on a mutually different horizontal surface with the 4th optical path of the light which has the said 2nd wavelength until. A first irradiation unit that irradiates light having a first wavelength to a first container containing a mixture of a sample and a reagent;
A second irradiation unit for irradiating the first container with light having a second wavelength;
The first irradiation unit and the second irradiation unit are disposed opposite to each other through the first container, and the first irradiation unit and the light irradiated from the first irradiation unit and the first irradiation unit are irradiated from the first irradiation unit. A first light receiving portion for receiving light transmitted through the container;
A third irradiating unit that irradiates a second container containing a sample of the same type as the sample with light having the first wavelength;
A fourth irradiation unit for irradiating the second container with light having the second wavelength;
The second irradiation unit is disposed opposite to the third irradiation unit and the fourth irradiation unit via the second container, and is irradiated from the fourth irradiation unit and the light irradiated from the third irradiation unit and transmitted through the second container. A second light receiving portion for receiving light transmitted through the container;
A calculation unit that calculates a change in absorbance of the sample due to the addition of the reagent based on the amount of light received by the first light receiving unit and the second light receiving unit;
The first wavelength is set to a wavelength region in which the transmittance of the mixture by the reagent is changed by the irradiation,
The second wavelength is set in a wavelength region where the transmittance of the mixture by the reagent does not change by the irradiation,
In the calculation unit, a ratio of a light amount signal of light emitted from the first irradiation unit and detected by the first light receiving unit and light emitted from the second irradiation unit and detected by the first light receiving unit is calculated. The absorbance of the mixture by logarithmic conversion, the light emitted from the third irradiation unit and detected by the second light receiving unit, and the light emitted from the fourth irradiation unit and detected by the second light receiving unit A measurement apparatus in which the absorbance of the sample is calculated by logarithmically converting the ratio of the amount of light signal, and the change in absorbance due to the addition of the reagent of the sample is calculated from the difference between the absorbance of the mixture and the absorbance of the sample . A first container containing a mixture of a sample and a reagent was irradiated with light having a first wavelength set in a wavelength region in which the transmittance of the mixture by the reagent changes due to the irradiation, and transmitted through the first container. Measuring a first light amount signal in a first light receiving unit that receives light having the first wavelength;
The first container containing the mixture is irradiated with light having a second wavelength set in a wavelength region in which the transmittance of the mixture by the reagent does not change due to the irradiation, and the first container transmitted through the first container Measuring the second light quantity signal in the second light receiving part that has received light having two wavelengths;
The light having the first wavelength, irradiating the second vessel containing the sample and the type of sample, the third in the third light receiving unit which receives light having the first wavelength transmitted through the second container Measure the light signal,
The light having the second wavelength, irradiating the second vessel containing the sample and the type of sample, the the fourth light receiving portion that receives the light having the second wavelength transmitted through the second container Measure the 4 light quantity signal,
Calculating the absorbance of the mixture by logarithmically converting the ratio of the first light signal and the second light signal;
Calculating the absorbance of the sample by logarithmically converting the ratio of the third light amount signal and the fourth light amount signal;
A measurement method for calculating a change in absorbance of the sample due to addition of the reagent from a difference between the absorbance of the mixture and the absorbance of the sample.

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