JPH04105025A - Fluorescence measuring device - Google Patents

Abstract

PURPOSE:To provide precise fluorescence measurability at all times by furnishing a color temp. correction filter between a light source and an opening of an integrating sphere on which a specimen to be measured has been installed, and setting the radiation illuminance ratio of the specimen in the energizing wave-length range to in the fluorescent wave-length range to a specified value. CONSTITUTION:The projection beam of light from a light source 2 stabilized in a constant voltage power supply 1 penetrates a color temp. correcting filter 25 to be projected into an integrating sphere 3. Dispersive beams of light from a reference white plate 15 and a specimen 14 to be fluorescent measured in the integrating sphere 3 are passed through a light chopper 17, triangular mirror 20, and diffraction lattice 21 to be separated into monochromic beams. These beams are passed through a slit 19, and each of the beams is given a specific wave-length, received by a light sensor 10, converted into an electric signal, which undergoes a computational process by a signal processing circuit 4 and a memory circuit 5. To set the energizing wave-length band, a grating 21 is driven by a cam 22 and a motor 23, and white light is separated into monochormic beams, and the projecting direction is controlled, and the radiation illuminance in the energizing wave-length band is determined. To set the fluorescent wave-length band, the white light is separated in the same manner into specified wave-lengths, and the radiation illuminance is determined, and the specified spectral power ratio is obtained.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a fluorescence measuring device for fluorescent materials.

[Prior Art] Conventionally, in fluorescence measuring devices using white light irradiation method and monochromatic light irradiation method for fluorescent materials, even if the type of light source is specified, the optical path length and optical axis are not always the same, and the irradiation light is not always the same. [Fred W. Billmeyer et al.: Color Research and Applications: Volume 5, No. 3]
Billmeyer:C0LORRe5earch
and Application: vol, 5
, No.

3)].

[Problems to be Solved by the Invention] The intensity of fluorescence changes depending on the spectral power of the irradiation light in the excitation wavelength range that enters the measurement sample, but the intensity of the radiation reflected by a perfectly diffuse reflector in the fluorescence wavelength range varies. will be evaluated in comparison to In particular, fluorescent brighteners and the like are evaluated by the intensity of fluorescence emitted in the visible range when excited with near-ultraviolet light, so the ratio to the radiation power of the excitation light irradiated to the measurement sample is important. .

In the above-described conventional technology, when measuring reflected light including fluorescence, light having a wavelength in the near ultraviolet region is affected by the spectral power distribution of the irradiated light from the light source, the spectral transmittance, and the spectral reflectance of the integrating sphere. Sufficient consideration was not given to irradiance or differences in optical path length and optical axis due to differences in measuring devices between monochromatic light illumination methods and white light illumination methods. Therefore, there is a problem in that machine differences between measuring devices or changes over time in the measurement sample affect the measured values.

An object of the present invention is to provide a fluorescence measuring device for fluorescent materials that uses a white light illumination method and a monochromatic light illumination method and has little difference in measured values between measuring devices or due to changes over time.

[Means for Solving the Problems] The gist of the present invention for achieving the above object is as follows.

(1) In a fluorescence measurement device that measures the fluorescence of a fluorescent material using a white light illumination method and a monochromatic light illumination method, a light source and a light receiver are installed at equal distances from the spectrometer, and the light source and the measurement sample are Illuminance control of a light source that can set a ratio of irradiance in the excitation wavelength range and irradiance in the fluorescence wavelength range of the measurement sample to a predetermined value by disposing a color temperature correction filter between the aperture of the attached integrating sphere. A fluorescence measuring device characterized by comprising means.

(2) The method described in (1) above, wherein the measurement sample is a fluorescent whitening agent, the excitation wavelength range is set to the near ultraviolet region of 350 to 400 nm, and the fluorescence wavelength range is set to 430 to 450 nm. Fluorescence measuring device.

(3) The measurement sample is a fluorescent chromatic sample, the excitation wavelength range is around 500nm, and the fluorescence wavelength range is around 600nm.
The fluorescence measurement device according to (1) above, characterized in that the fluorescence measurement device is set at around m.

In the present invention, the excitation wavelength range is 350 to 400 nm, and the excitation wavelength range is 430 to 4 nm, as described above, for the measurement of the fluorescent brightener sample.
The purpose is to select 50 nm as the fluorescence wavelength range.

Furthermore, for measurement of fluorescent chromatic samples, the excitation wavelength range is selected around 500 nm, and the fluorescence wavelength range is selected around 600 nm.

Under these conditions, the white light emitted from the light source is used as diffuse illumination light to irradiate the measurement sample through the color temperature correction filter, and the reflected light is received by the photomultiplier tube and converted into photocurrent. Similarly, even when an excitation wavelength band is set, light is received by a photomultiplier tube through the color temperature correction filter and converted into a photocurrent.

The spectral power distribution of the sample irradiation light is defined from the ratio of the intensities of the two diffused irradiation lights. This makes it possible to obtain measured values that are free from differences between measuring instruments or due to changes in measurement over time.

[Operations] The reason why the present invention can always perform highly accurate fluorescence measurement is that the excitation wavelength band and fluorescence wavelength band of the sample are set, the wavelength of the fluorescence measurement device is set to these, and the irradiation intensity of the light source is adjusted. The reason lies in the fact that the spectral power distribution of synchrotron radiation is defined through control.

[Example] The present invention will be specifically explained using FIGS. 1 to 5.

FIG. 1 is a schematic diagram illustrating an embodiment of the fluorescence measuring device of the present invention.

The irradiation light emitted from the light source 2, which is stabilized by the constant voltage power supply section 1 and turned on with a voltage controlled to obtain a predetermined illuminance, passes through the color temperature correction filter 25 and is irradiated into the integrating sphere 3. Ru. The inner wall surface of the integrating sphere 3 is coated with a white diffusion coating of barium sulfate or the like.

Fluorescence measurement sample 1 attached to a predetermined position within the integrating sphere 3
4 and the reference white plate 15 are split by an optical chopper mirror 17, then passed through a triangular mirror 20 and a diffraction grating 2.
1, it is split into monochromatic light.

The monochromatic light is made into monochromatic light of a predetermined wavelength by a predetermined slit 19, and is received by a photodetector 10 and its intensity is measured. The signal converted into an electrical signal by the photodetector 10 is processed by a signal processing circuit 4 and a memory circuit 5.

The signal processing circuit 4 and the memory circuit 5 also include processing such as amplification of the converted electrical signal, digitization, memory, program control of the light source, output display, or printing to a printer (not shown). It is something that

Incidentally, a color temperature correction filter 25 is slidably attached to the opening of the integrating sphere 3 by a filter holding member 26 in order to remove the influence of the longer wavelength side of the irradiated light when measuring the 1-minute optical power ratio. The filter holding member 2
6 can be installed in a sliding manner to make the spectrometer dustproof.

The opening of the integrating sphere 3 is located at a position where reflected light reflected at a small angle, for example about 8 degrees, with respect to the normal to each surface of the measurement sample 4 and reference white plate 15 can be incident.

Next, to set the excitation wavelength band, move the grating 21 to the cam 2.
2 and a motor 23, the white light is separated into monochromatic light, the irradiation direction is controlled, and the irradiance in the excitation wavelength band is determined.

Next, in the same manner, in order to set a fluorescence wavelength band, white light is separated into predetermined wavelengths to obtain irradiance, and a predetermined spectral power ratio is obtained.

The light source 2 is housed in a light source case 6 and is connected to the constant voltage power source 1 via a movable light source cable 9. The photodetector 0 is housed in a light receiving case 7, and is also connected to the signal processing circuit 4 by a movable signal cable 8.

The light source part case 6 and the light receiving part case 7 are fixed by a common guide member 13, 13' which fixes the integrating sphere 3 and the spectrometer part 18 so that there is no deviation on the optical axis.

In the above, the photodetector 1 is connected from the end surface of the common guide member 13.
By making the distance to the photocell surface of 0 and the distance from the end surface of the common guide member 13' to the light emitting point of the light source 2 equal, the white light illumination method shown in FIG. 1 and the monochrome illumination method shown in FIG. It is easy to replace the optical illumination method, and there is no difference in optical path length or deviation in the optical axis.

In addition, in this embodiment, the integrating sphere 3 and the optical chopper section 1 are
6. Although the spectrometer section 18 and the wavelength drive system 24 constitute the optical system of the measuring device, it is also possible to use an optical system composed of a plurality of interference filters as a simple type.

FIG. 2 is a schematic diagram illustrating the monochromatic light illumination method of the present invention.

This is the measuring instrument shown in FIG. 1, with the light source section and light receiving section replaced. As mentioned above, the distance from the end face of the common guide member 13 to the photocell surface of the photodetector 10 is equal to the distance from the end face of the common guide member 13' to the light emitting point of the light source 2, so they are replaced. It is.

When measuring a fluorescent sample using the white light illumination method, the spectral energy distribution emitted from the light source 2 can be corrected as illustrated in FIG. 3.

This means that the spectral energy of the light source 2 is the power of light at a short wavelength λ1 (for example, 360 nm) as al, bl, and the power of light at a long wavelength λ2 (for example, 430 nm) as a2,
If b2, it can be defined by the ratios b+/a+ and b2/az.

In addition, as shown in FIG. 4, the excitation wavelength λ of the fluorescent sample is
It can be corrected by finding the ratio with the fluorescence wavelength ^4.

Furthermore, by using the optical system shown in Figures 1 and 2,
Measurements using the white light illumination method and monochromatic light illumination method can be easily performed using the same fluorescence measurement sample.

FIG. 5 illustrates the results of measuring a fluorescent brightener sample using the two illumination methods described above.

In addition, the said fluorescent whitening agent emits fluorescence at 430-450 nm. Further, a fluorescent chromatic sample emits fluorescence at around 600 nm. Therefore, it is determined which category the sample falls under, and in the case of the former, the excitation wavelength range is set to the near ultraviolet range of 350 to 450 nm, and the fluorescence wavelength range is set to 430 to 450 nm. Similarly, in the latter case, the excitation wavelength range is set to around 500 nm and the fluorescence wavelength range is set to around 600 nm.

The spectral reflectance measured in this manner is shown in curve a for the case of the monochromatic light illumination method, and curve A for the case of the white light illumination method.

According to this embodiment, since the excitation wavelength band and the fluorescence wavelength band can be alternately set and measured, measurement values with good reproducibility can be obtained with little influence of changes over time.

[Effects of the Invention] According to the present invention, when measuring the fluorescence of a fluorescent sample, it is possible to easily compare the measured values with the monochromatic light illumination method and the measured values with the white light illumination method.

In addition, fluctuations in the irradiation power of the light source can be corrected based on the ratio of the measured value at a wavelength that emits fluorescence in the visible range and the measured value at a wavelength that emits fluorescence in the excitation wavelength range, so highly accurate measured values can be reproduced. You can get it easily.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are schematic diagrams explaining the present invention in detail;
Figure 3 is a graph showing the relationship between light energy and wavelength, Figure 4 is a graph showing the distribution of spectral reflectance in the excitation wavelength band and fluorescence wavelength band, and Figure 5 is a graph showing the relationship between the monochromatic light irradiation method and the white light irradiation method. It is a graph showing distribution of spectral reflectance. 1... constant voltage power supply section, 2... light source, 3... integrating sphere,
4 signal processing circuit, 5... memory circuit, 6... light source part case, 7... light receiving part case, 8... signal cable, 9... light source cable, 10... photodetector, 11・・・
Common mounting member, 12... Common fixing member, 13...
Common guide member, 14... Fluorescence measurement sample, 15... Reference white plate, 16... Optical chopper section, 17... Optical chopper mirror 18... Spectrometer section, 19... Slit,
20...Mirror 21...Grating, 22...
Cam, 23... Motor, 24... Wavelength drive system, 25
...Color temperature correction filter, 26... Filter holding member, a... Monochromatic light illumination method, b... White light illumination method. Figure 1 Figure 2 Holding member.

Claims (1)

[Claims] 1. In a fluorescence measuring device that measures the fluorescence of a fluorescent material using a white light illumination method and a monochromatic light illumination method, a light source and a light receiver are each installed at an equal distance from a spectrometer, and the light source and the opening of the integrating sphere to which the measurement sample is attached, and the ratio of the irradiance in the excitation wavelength range to the irradiance in the fluorescence wavelength range of the measurement sample is set to a predetermined value. 1. A fluorescence measuring device characterized by comprising means for controlling illuminance of a light source. 2. The measurement sample is a fluorescent whitening agent, and the excitation wavelength range is set in the near ultraviolet region of 350 to 400 nm, and the fluorescence wavelength range is set to 430 to 450 nm. Fluorescence measuring device. 3. The measurement sample is a fluorescent chromatic sample, and the excitation wavelength range is around 500 nm and the fluorescence wavelength range is around 600 nm.
2. The fluorescence measuring device according to claim 1, wherein the fluorescence measuring device is set in the vicinity of the fluorescence measuring device.