WO2019069526A1

WO2019069526A1 - Spectrometer

Info

Publication number: WO2019069526A1
Application number: PCT/JP2018/026263
Authority: WO
Inventors: 小田　竜太郎
Original assignee: 株式会社島津製作所
Priority date: 2017-10-04
Filing date: 2018-07-12
Publication date: 2019-04-11

Abstract

A slit plate 10 constituting a variable slit portion and an aperture plate 12 constituting a numerical aperture adjustment portion are arranged between a mirror 8 and a spectroscope 14. A slit drive mechanism 11 drives the slit plate 10 on the basis of a signal from a control unit 18 and arranges, on the optical axis of light from the mirror 8, one of a plurality of slits 10a provided in the slit plate 10. An aperture drive mechanism 13 arranges an aperture 12a corresponding to the slit 10a arranged on the optical axis of the light from the mirror 8, on the same optical axis on the basis of a signal from the control unit 18.

Description

Spectrometer

The present invention relates to a spectrometry apparatus for analyzing a sample in a sample cell by irradiating light from a light source to a sample cell, and splitting the light from the sample cell with a spectrometer and guiding the light to a light detector for detection. It is a thing.

FIG. 8 shows an example of a conventional spectrometer.

This spectrometer measures the light from the light source 2 to the sample cell 6, guides the light transmitted through the sample cell 6 to the light detector 16, and measures the absorbance of the light of a specific wavelength of the sample in the sample cell 6. It is. A mirror 4 is provided as an irradiation optical system for guiding the light from the light source 2 to the sample cell 6, and a mirror 8, a slit 10a, and a measurement optical system for guiding the light transmitted through the sample cell 6 to the light detector 16. A diffraction grating 14 is provided. The slit 10 a is provided in the slit plate 10. The slit plate 10 is disposed between the mirror 8 and the diffraction grating 14.

The light emitted from the light source 2 is irradiated to the sample cell 6 by the mirror 4, and the light transmitted through the sample cell 6 is reflected by the mirror 8, passes through the slit 10 a, and is dispersed by the diffraction grating 14 onto the light detector 16. It is imaged and detected.

The sample cell 6 is connected to, for example, the downstream side of the analysis column of the separation channel of the liquid chromatograph, and a liquid containing the sample separated for each component in the separation column flows. The photodetector 16 detects a temporal change in the intensity of light transmitted through the sample cell 6, and detects the component concentration of each sample contained in the sample by the temporal change in absorbance based on the detected data. .

Among such spectrometers, there is one in which the width of a slit provided in front of a spectrometer is configured to be changeable (see, for example, Patent Document 1). When the slit width is narrowed, the light entering the spectrometer is limited to the light near the center of the light beam of the measurement light, and the wavelength resolution of the spectrometer is enhanced. Conversely, increasing the slit width increases the amount of measurement light incident on the spectrometer and increases the detection sensitivity of the measurement (signal intensity), but also takes in light at a position distant from the center of the measurement light beam. The resolution is reduced.

Unexamined-Japanese-Patent No. 5-215604

There is a numerical aperture (aperture stop) of the spectrometer as an element other than the slit width that affects the wavelength resolution and detection sensitivity of the spectrometer. The numerical aperture of a spectroscope is the range of the spectroscope of the spectroscope used for spectroscopy. When the numerical aperture is reduced, spectroscopy is performed using a limited range on the center side of the spectral surface, and when the numerical aperture is increased, spectroscopy is performed using a wide range of the spectral surface. Therefore, if the numerical aperture is increased, light dispersed in a wide range of the spectral surface of the spectroscope can be guided to the detector, and the detection sensitivity becomes high, but at a position of poor spectral accuracy away from the center of the spectral surface The wavelength resolution is lowered because the split light is also used. Conversely, if the numerical aperture is reduced, the wavelength resolution will be high but the detection sensitivity will be low.

Therefore, there is a problem that the desired wavelength resolution can not be obtained unless the numerical aperture is sufficiently reduced even if the slit width is narrowed. Therefore, in order to obtain high wavelength resolution, it is necessary to set the numerical aperture of the spectroscope to a small numerical aperture such that sufficient wavelength resolution can be obtained when the slit width is minimized.

However, if the numerical aperture is set to a smaller value, even if the slit width is broadened to increase the detection sensitivity, only light incident on a narrow range of the spectral surface of the spectroscope can be used for measurement. Can not raise. That is, in the conventional apparatus, the high sensitivity measurement is limited in the spectrometric apparatus set to obtain high wavelength resolution, and the high wavelength resolution is set in the high sensitivity measurement possible. There was a problem that was not obtained.

Therefore, an object of the present invention is to provide a spectrometry device capable of performing measurement with wavelength resolution or sensitivity according to purpose from measurement with high wavelength resolution to measurement with high sensitivity.

The present invention comprises a light source, a light detector, a sample cell made of a light transmitting material, for circulating or containing a sample, an irradiation optical system for guiding light from the light source to the sample cell, a sample cell And a measurement optical system having a spectroscope for separating light from the sample cell and guiding the light from the sample cell to the light detector, wherein the measurement optical systems have widths relative to one another. A variable slit section for arranging a slit selected as a use slit among the slits on the optical path of light guided to the spectroscope, and a numerical aperture of the spectroscope corresponding to a width of the use slit It is characterized by having a numerical aperture adjustment part which changes into a thing.

The spectroscopic measurement device of the present invention can be applied to one in which the measurement optical system is configured to guide the light transmitted through the sample cell to the light detector.

In addition, the irradiation optical system is configured to take out the excitation component for exciting the sample contained in the sample cell among the light from the light source and guide it to the sample cell, and the measurement optical system separates the light from the sample cell The present invention can also be applied to one configured to take out fluorescence components emitted from a sample by means of a light source and to guide it to a light detector.

The variable slit portion is composed of a light shielding slit plate disposed perpendicular to the light path of light guided to the spectroscope and provided with a plurality of slits having different widths, and a slit driving mechanism for driving the slit plate The slit drive mechanism may drive the slit plate so that the slit selected as the use slit is on the optical path of the light guided to the spectroscope, in which case the numerical aperture adjustment unit It is composed of a light shielding aperture plate disposed perpendicular to the light path of light guided to the spectroscope and provided with apertures corresponding to the slits of the slit plate, and an aperture drive mechanism for driving the aperture plate. The aperture drive mechanism may drive the aperture plate so that the aperture corresponding to the light is on the optical path of the light guided to the spectroscope.

One example of a preferred embodiment is one in which the aperture drive mechanism is configured to move the aperture plate in a direction perpendicular to the light path.

Another example of the preferred embodiment is that the aperture drive mechanism is configured to rotationally drive the aperture plate, and each aperture is provided on the same track on the aperture plate drawn by the aperture plate being rotationally driven. It is

In the above two examples, the slit plate is held by the same holding member as the aperture plate, and the aperture drive mechanism drives the slit plate as the slit drive mechanism together with the aperture plate by driving the holding member. Is preferred. Then, the slit and the aperture can be changed by one drive mechanism, and the cost of the apparatus can be reduced and the apparatus can be miniaturized.

In the present invention, in the measurement optical system for separating the light from the sample cell by the spectroscope and guiding the light to the light detector, the numerical aperture of the spectroscope is disposed on the light path of the light guided to the spectroscope by the variable slit portion. Since the numerical aperture adjustment part which changes it into a thing according to the use slit is provided, the numerical aperture of a spectrometer can be made into the numerical aperture suitable for the width | variety of a slit. Thereby, when the slit width is narrowed and analysis is performed with high resolution, the numerical aperture of the spectrometer can be reduced to sufficiently enhance the wavelength resolution, and conversely, the slit width is expanded to perform high sensitivity analysis. When this is done, the numerical aperture of the spectroscope can be increased to increase the amount of light incident on the detector, and sufficient detection sensitivity can be obtained.

It is a block diagram which shows roughly one Example of a spectrometry apparatus. It is a perspective view which shows an example of the numerical aperture adjustment part of the Example. It is a perspective view which shows the other example of the numerical aperture adjustment part of the Example. It is a block diagram which shows roughly the other Example of a spectrometry apparatus. It is a perspective view which shows an example of the numerical aperture adjustment part of the Example. FIG. 7 schematically shows still another embodiment of a spectrometry apparatus. It is a perspective view which shows an example of the slit variable mechanism and numerical aperture adjustment part in the Example. It is a block diagram which shows roughly an example of the conventional spectroscopy apparatus.

One embodiment of the spectrometer will be described with reference to FIG.

This spectrometric device irradiates the sample cell 6 with the light from the light source 2 composed of, for example, a deuterium lamp, disperses the light transmitted through the sample cell 6 with the spectroscope 14 and makes the light enter the light detector 16 The detection is performed to analyze the sample components flowing through the sample cell 6. For example, a sample which has passed through a separation column of liquid chromatograph flows in the sample cell 6.

A mirror 4 is provided as an illumination optical system for guiding light emitted from the light source 2 to the sample cell 6. Light emitted from the light source 2 is collected by the mirror 4 and guided to the sample cell 6. A mirror 8, a slit plate 10, an aperture plate 12 and a spectroscope 14 are provided as a measurement optical system for guiding the light from the sample cell 6 to the light detector 16. The light transmitted through the sample cell 6 is reflected by the mirror 8, passes through the slit 10 a provided in the slit plate 10 and the aperture 12 a provided in the aperture plate 12, and enters the spectroscope 14 and is separated by the spectroscope 14 Light is directed to the light detector 16. The spectroscope 14 is, for example, a diffraction grating.

The slit plate 10 disposed between the mirror 8 and the spectroscope 14 is provided with a plurality of slits 10 a in a light shielding plate member. The slit plate 10 is disposed perpendicularly to the optical axis of the light guided from the mirror 8 to the spectroscope 14. The aperture plate 12 disposed closer to the spectroscope 14 than the slit plate 10 between the mirror 8 and the spectroscope 14 has a plurality of apertures 12 a provided in a light shielding plate member. In this example, the aperture plate 12 is disposed in parallel with the slit plate 10.

The slit plate 10 is driven by the slit drive mechanism 11, and the slit drive mechanism 11 is controlled by the control unit 18. The slit drive mechanism 11 drives the slit plate 10 based on a signal from the control unit 18 and arranges one of the plurality of slits 10 a provided in the slit plate 10 on the optical axis of the light from the mirror 8 Do. The aperture plate 12 is driven by the aperture drive mechanism 13, and the aperture drive mechanism 13 is also controlled by the control unit 18. The aperture drive mechanism 13 arranges the aperture 12a corresponding to the slit 10a disposed on the optical axis from the mirror 8 on the same optical axis based on the signal from the control unit 18.

An example of the configuration of the variable slit portion and the numerical aperture adjustment portion will be described with reference to FIG.

In this example, the slit plate 10 is formed of a flat plate-like member made of a light shielding material, and slits 10a-1, 10a-2 and 10a-3 having different widths are provided in a line in the vertical direction in the plane. ing. The slit plate 10 is arranged perpendicularly to the optical axis so that the slits 10a-1, 10a-2 and 10a-3 are on a straight line perpendicular to the optical axis of the light from the mirror 8. .

The aperture plate 12 is also formed of a flat plate-like member made of a light shielding material like the slit plate 10, and the apertures 12a-1, 12a-2 and 12a- corresponding to the respective slits of the slit plate 10 in the plane thereof. 3 are provided in a line in the vertical direction. The aperture plate 12 is disposed opposite to the slit plate 10 in parallel. The aperture 12a-1 is disposed at a position corresponding to the slit 10a-1, the aperture 12a-2 is disposed at a position corresponding to the slit 10a-2, and the aperture 12a-3 is disposed at a position corresponding to the slit 10a-3. The corresponding position means a position where the slit of interest is disposed on the same optical path when the slit is disposed on the optical axis of the light from the mirror 8. The size of each aperture 12a-1, 12a-2 and 12a-3 optimizes the numerical aperture of the spectroscope 14 when the target slit 10a-1, 10a-2 or 10a-3 is used The size is set.

The slit plate 10 and the aperture plate 12 are held by a spacer 20 which is a common holding member. The spacer 20 is moved in the vertical direction by the vertical drive mechanism 22 to drive the slit plate 10 and the aperture plate 12 in the vertical direction. In this example, the slit drive mechanism 11 and the aperture drive mechanism 13 shown in FIG. 1 are realized by the vertical drive mechanism 22. Examples of the configuration of the vertical drive mechanism 22 include one that moves the spacer 20 up and down by rotating a ball screw with a motor.

With the above configuration, when the slit 10a-1 is disposed on the optical axis of the light from the mirror 8, the aperture 12a-1 is automatically disposed on the same optical axis, and when the slit 10a-2 is disposed, the automatic operation is performed. Specifically, the aperture 12a-2 is disposed on the same optical axis, and when the slit 10a-3 is disposed, the aperture 12a-3 is automatically disposed on the same optical axis. That is, by arranging the slit 10a used on the optical axis according to the purpose of measurement, the aperture 12a corresponding to the slit 10a is automatically arranged on the same optical axis, and the numerical aperture of the spectroscope 14 is used It is automatically adjusted to a suitable one for the slit 10a.

In the example of FIG. 2, the slits 10 a-1, 10 a-2 and 10 a-3 and the apertures 12 a-1, 12 a-2 and 12 a-3 are respectively arranged in a line in the vertical direction. 10a-2 and 10a-3 and the apertures 12a-1, 12a-2 and 12a-3 may be arranged in a line in the left-right direction. In that case, the slit drive mechanism 11 and the aperture drive mechanism 13 can be realized by providing a mechanism for driving the slit plate 10 and the aperture plate 12 in the left-right direction instead of the vertical drive mechanism 22.

As another example of the configuration of the variable slit portion and the numerical aperture adjustment portion, as shown in FIG. 3, the slit 10 a and the aperture used by rotating the slit plate 10 and the aperture plate 12 by the rotation drive mechanism 26. There is one that switches 12a. In this example, the slit plate 10 and the aperture plate 12 are both formed by a fan-shaped plate member and fixed to a common shaft 24. The rotary drive mechanism 26 rotationally drives both the slit plate 10 and the aperture plate 12 at the same time by rotationally driving the shaft 24 to realize the slit drive mechanism 11 and the aperture drive mechanism 13 of FIG. 1.

The slits 10a-1, 10a-2 and 10a-3 are disposed on the path of the optical axis of the light from the mirror 8 which is drawn on the plane of the slit plate 10 as the slit plate 10 is rotationally driven. The apertures 12a-1, 12a-2 and 12a-3 have corresponding slits 10a on the path of the optical axis of the light from the mirror 8 which is drawn on the plane of the aperture plate 12 when the aperture plate 12 is rotationally driven. It is disposed at a position facing -1, 10a-2 and 10a-3.

According to the above configuration, as in the example of FIG. 2, by arranging the slit 10a used on the optical axis according to the purpose of measurement, the aperture 12a corresponding to the slit 10a is automatically arranged on the same optical axis. Once placed, the numerical aperture of the spectroscope 14 is automatically adjusted to one suitable for the slit 10a used.

In the two embodiments, the slit drive mechanism 11 and the aperture drive mechanism 13 in FIG. 1 are commonly used by the vertical drive mechanism 22 or the rotary drive mechanism 26. However, the slit drive mechanism 11 and the aperture drive mechanism 13 are separately provided. It may be an independent drive mechanism.

Also, the numerical aperture adjustment unit is not limited to one that switches the aperture (aperture 12a) disposed on the optical axis of the light from the mirror 8 as in the example of FIG. 2 or FIG. The incident area of the spectroscope 14 may be limited by the aperture plate 12. In this example, the aperture plate 12 is composed of a pair of L-shaped plates 12-1 and 12-2, as shown in FIG.

In this example, the aperture drive mechanism 13 is provided independently of the slit drive mechanism 11, and the inner opening region (in the in-plane direction by moving the pair of L-shaped plates 12-1 and 12-2) Adjust the size of the aperture 12a. The controller 18 controls the plates 12-1 and 12-2 through the aperture drive mechanism 13 so as to form an opening area 12a having a size corresponding to the size of the slit 10a disposed on the optical axis of the light from the mirror 8. Drive. The slit plate 10 may be the same as the example of FIG. 2 or FIG. 3

FIG. 6 shows another embodiment of the spectrometer.

The spectrometer of this embodiment extracts a wavelength component (excitation light) corresponding to excitation light from the light emitted from the light source 30 and guides it to the sample cell 38, and detects the fluorescence emitted from the excited sample. The concentration of the specific component in the sample is measured by guiding it to 44 and measuring its fluorescence intensity. In this spectrometric measurement apparatus, a mirror 31, an entrance slit 32, a spectroscope 34, and an exit slit 36 are provided as an irradiation optical system for extracting excitation light from light from the light source 30 and guiding it to the sample cell 38. A mirror 40, an entrance slit 10a, an aperture 12a, a spectroscope 42, and an exit slit 10b are provided as a measurement optical system for guiding the fluorescence emitted from the excited sample to the photodetector 44. The inlet slit 10 a and the outlet slit 10 b are provided in one slit plate 10 as a variable slit portion. The aperture 12 a is provided on the aperture plate 12 as a numerical aperture adjustment unit disposed closer to the spectroscope 42 than the slit plate 10.

The light emitted from the light source 30 is guided by the mirror 31 to the spectroscope 34 through the entrance slit 32 and dispersed, and only the wavelength component corresponding to the excitation light among the light dispersed by the spectroscope 34 is the exit slit 36. The sample cell 38 is irradiated through. The fluorescence emitted from the excited sample is reflected by the mirror 40 and guided to the spectroscope 42 through the entrance slit 10a and the aperture 12a. Of the light separated by the spectroscope 42, only the wavelength component corresponding to the fluorescence is guided to the light detector 44 through the exit slit 10b, and the intensity is detected.

As the slit plate 10 and the aperture plate 12, an example shown in FIG. 7 can be mentioned. The slit plate 10 in this example is formed of a disk-shaped plate-like member, and the inlet slits 10a-1, 10a-2 and 10a-3 arranged in the circumferential direction in the plane and the outlet slits corresponding to them. 10b-1, 10b-2 and 10b-3 are provided. The center of the slit plate 10 is fixed to the rotation shaft 24. The aperture plate 12 is also fixed to the rotating shaft 24, and is configured to be rotationally driven together with the slit plate 10 by a common drive mechanism.

The aperture plate 12 is provided with apertures 12a-1, 12a-2 and 12a-3 at positions corresponding to the inlet slits 10a-1, 10a-2 and 10a-3, respectively.

The exit slits 10b-1, 10b-2 and 10b-3 lead from the spectroscope 42 to the light detector 44 also when the corresponding entrance slits 10a-1, 10a-2 or 10a-3 respectively are used. It is provided in the position which can be arrange | positioned on the optical axis of the fluorescence component to be mixed. In this example, corresponding inlet and outlet slits are arranged in symmetrical positions about the axis of rotation 24.

Although illustration is omitted, as in the example of FIG. 3, the rotation shaft 24 is driven by a rotation drive mechanism. By rotationally driving the rotary shaft 24 by the rotary drive mechanism, the inlet slit 10a is switched to any of 10a-1, 10a-2 and 10a-3, and at the same time the outlet slit 10b and the aperture 12a correspond to the inlet slit It is automatically switched to things.

In the embodiment described above, three types of slits 10a and apertures 12a are provided and switched, but two types or four or more types of slits 10a and apertures 12a may be used.

2, 30

light source

4, 8, 31, 40

mirrors

6, 38 sample cell 10 slit plate 10 a slit (inlet slit)
10b Exit Slit 11 Slit Driving Mechanism 12 Aperture Plate 12a Aperture 13 Aperture Driving Mechanism 14

Spectroscope

16, 44 Photo Detector 18 Control Unit 20 Spacer (Holding Member)
22 Vertical drive mechanism 24 Rotary shaft 26 Rotary drive mechanism

Claims

A light source, a light detector, a sample cell made of a light transmissive material for circulating or containing a sample, an irradiation optical system for guiding light from the light source to the sample cell, and the sample cell And a measurement optical system having a spectroscope for spectrally separating light from the sample cell and guiding the light from the sample cell to the light detector,
The measurement optical system includes a plurality of slits different in width from each other, and a variable slit unit that arranges a slit selected as a use slit among the slits on an optical path of light guided to the spectroscope, and the spectroscope And a numerical aperture adjustment unit configured to change the numerical aperture of the aperture to a value corresponding to the width of the slit used.
The spectrometry apparatus according to claim 1, wherein the measurement optical system guides light transmitted through the sample cell to the light detector.
The irradiation optical system takes out, from the light from the light source, an excitation component for exciting a sample contained in the sample cell, and guides it to the sample cell.
The spectrometric measurement apparatus according to claim 1, wherein the measurement optical system separates the light from the sample cell with the spectroscope, takes out the fluorescent component emitted from the sample, and guides the fluorescence component to the light detector.
The variable slit portion includes a light shielding slit plate disposed perpendicular to the light path of light guided to the spectroscope and provided with a plurality of slits having different widths, and a slit driving mechanism for driving the slit plate. Driving the slit plate by the slit drive mechanism so that the slit selected as the use slit is on the optical path of the light guided to the spectroscope,
The numerical aperture adjustment unit is disposed perpendicular to the optical path of light guided to the spectroscope, and has a light shielding aperture plate provided with apertures corresponding to the slits of the slit plate and an aperture for driving the aperture plate 4. The driving device according to claim 1, wherein the aperture drive mechanism drives the aperture plate such that the aperture corresponding to the use slit is on the optical path of light guided to the spectroscope. The spectrometer according to any one of the preceding claims.
5. The spectrometer according to claim 4, wherein the aperture drive mechanism moves the aperture plate in a direction perpendicular to a light path of light guided to the spectroscope.
The aperture drive mechanism according to claim 5, wherein the aperture drive mechanism rotationally drives the aperture plate, and the respective apertures are provided on the same track on the aperture plate which is drawn by the aperture plate being rotationally driven. Spectroscopic measuring device.
The slit plate is held by a holding member common to the aperture plate,
The spectrometry apparatus according to any one of claims 4 to 6, wherein the aperture drive mechanism drives the slit plate as the slit drive mechanism together with the aperture plate by driving the holding member.