JP3609029B2 - Detector and liquid sample measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a detection apparatus and a liquid sample measurement apparatus including a flow cell used for measuring a liquid sample with various analyzers.
[0002]
[Prior art]
The flow cell distributes liquid samples in a dissolution tester for monitoring the state of dissolution of pharmaceutical tablets, a detection device for an analysis device such as a liquid chromatograph, a detection device for a measurement device for monitoring factory waste liquid, etc. It is used to measure the concentration of a predetermined component in a liquid sample by measuring the absorbance.
[0003]
Usually, a flow cell having one optical path length is used. When a liquid sample is measured with a flow cell having a single optical path length, the sensitivity is insufficient when the concentration of the sample component is too low, and conversely, the absorbance becomes saturated when the concentration is too high.
[0004]
Although the purpose is not to eliminate such inconveniences based on the dynamic range of measurement, one flow cell having two optical path lengths has been proposed (see Japanese Patent Laid-Open No. 4-268443). Therefore, the proposed flow cell calculates the ratio of transmittance measured by two flow cells having different optical path lengths, thereby absorbing the measurement light by the components in the sample attached to the glass windows of the two flow cells and the glass window. It is intended to cancel the measurement error of the transmittance due to the reflection of the measurement light in and to measure the exact concentration of the sample component in the flow cell. For this reason, the cells having two optical path lengths are irradiated with light having the same intensity, and the intensity of the light transmitted through each cell is measured. However, if the flow cell has two optical path lengths, a liquid sample can be measured over a wide concentration range.
[0005]
[Problems to be solved by the invention]
In the proposed flow cell, in order to irradiate two cells having different optical path lengths with the same amount of light, the optical system for dividing the light from the light source into two optical paths and adjusting the light amount to the same amount Is required. As a result, not only does the cost of such an optical system increase, but it is not easy to equalize the light quantities of the two divided light beams.
[0006]
Further, in the proposed flow cell, the outer dimensions of two cells having different optical path lengths are different, and the outer dimension of a cell portion having a long optical path length is larger than that of a cell portion having a short optical path length. It has become. This means that the external dimensions of the optical path length in the liquid sample and the optical path length in the vessel wall made of glass or quartz of the flow cell are different. The refractive index of the liquid sample is close to the refractive index of glass or quartz, but the refractive index of air is smaller than them, so the conditions for transmitting light are different in two cell parts with different optical path lengths. An error occurs when obtaining the concentration from the absorbance in both cell portions.
[0007]
With the present invention is to be able to make measurements over a wide concentration range, improve the measurement accuracy, and further for the purpose of easily be Rukoto the optical axis adjustment.
[0008]
[Means for Solving the Problems]
In the flow cell used in the present invention , a plurality of cells having the same light transmission direction and different optical path lengths are integrated and arranged on one liquid sample channel, and the outer dimensions of those cells in the light transmission direction are the same. It has become.
[0009]
Since a plurality of cells having different optical path lengths are arranged on one liquid sample channel, measurement can be performed over a wide concentration range by selecting cells having an appropriate optical path length in accordance with the concentration of the liquid sample. .
Further, since the outer dimensions of the cells in the light transmission direction are the same, the sum of the optical path length in the liquid sample and the optical path length in the flow cell wall is equal.
[0010]
The detection device of the present invention includes this flow cell, an irradiation optical system that includes a light source and irradiates the flow cell with light from the light source as measurement light on a single optical path, and receives and detects light transmitted through the flow cell. A light receiving optical system, a spectroscopic means provided in either the irradiation optical system or the light receiving optical system, and a first one selected from a plurality of cells in the flow cell and positioned on the optical path of the irradiation optical system A cell moving mechanism.
A liquid sample measuring device of the present invention includes the above-described detection device including the flow cell, and a sample supply mechanism that supplies a liquid sample to be measured to the detection device, and the irradiation optical system includes the light source A plurality of light sources having different wavelength characteristics, and a common condenser lens for guiding light from these light sources to the single optical path as measurement light, and total reflection of the light from the plurality of light sources, respectively An optical system comprising mirrors for guiding different portions of the condenser lens is provided.
By providing a plurality of light sources having different wavelength characteristics, the measurement wavelength region can be expanded. Then, light from a plurality of light sources is guided to one common optical path using different parts of the common optical element, so that the optical axis can be easily adjusted.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment of the present invention, the irradiation optical system is arranged so that the optical path irradiating the flow cell is in the horizontal direction, the flow cell is installed in the vertical direction so that a plurality of cells having different optical path lengths are arranged up and down, The first cell moving mechanism is a mechanism for positioning the cell on the optical path of the irradiation optical system by moving the flow cell in the vertical direction.
The optical path length can be switched by a simple mechanism that simply moves the flow cell up and down.
[0012]
Another embodiment of the present invention includes a second cell moving mechanism that includes a plurality of flow cells, selects one of the plurality of flow cells, and positions the flow cell on the optical path of the irradiation optical system.
In this embodiment, since a plurality of samples can be measured simultaneously, the operating rate is improved.
[0013]
In the preferred embodiment, the plurality of flow cells are arranged in a horizontal direction along a vertical plane perpendicular to the optical path of the irradiation optical system, and the second cell moving mechanism is moved to a predetermined direction by moving the flow cell in the horizontal direction. The flow cell is positioned on the optical path of the irradiation optical system. Since the second cell moving mechanism only moves the cell in the horizontal direction, the mechanism becomes simple.
[0014]
Light from a plurality of light sources may be simultaneously guided to a common optical path, or one of them may be selected by a shutter and introduced into the common optical path. When light from a plurality of light sources is simultaneously guided to the optical path, a wide wavelength region can be continuously measured without switching the light sources. If the light from one of the light sources interferes with the measurement of the light from the other light source, or if you want to guide only the light from the light source that emits a bright line to the optical path when calibrating using the bright line, use the shutter. Thus, only light from a desired light source may be guided.
[0015]
In the liquid sample measuring apparatus of the present invention, the sample supply mechanism can be an analysis apparatus main body such as a dissolution tester or a liquid chromatograph, or a piping system for supplying a sample to be measured such as a factory waste liquid.
[0016]
【Example】
FIG. 1 shows an example of a flow cell used in the present invention.
The flow cell 2 includes two cells 2a and 2b that are connected vertically. These cells 2a and 2b have the same light transmission direction (in-plane direction in the figure), and the optical path length is 10 mm for the cell 2a. 2b is 1 mm. The outer dimensions T of the two cells 2a and 2b are both equal to 13.0 mm. The optical path width W (width in the direction orthogonal to the light transmission direction) of both the cells 2a and 2b in the light transmission direction is equal to 13.0 mm. The lower end of the lower cell 2 b is connected to the liquid sample inlet 4, and the upper end of the upper cell 2 a is connected to the liquid sample outlet 6. The liquid sample enters from the inlet 4 and is discharged from the outlet 6 through the cells 2b through 2a. The flow cell 2 is made of synthetic quartz, and the wall thickness in the light transmission direction is 1.5 mm for the cell 2 a and 6.0 mm for the cell 2 b.
[0017]
In the detection apparatus using this flow cell, there is one optical path for measurement, and the flow cell 2 is moved vertically according to the concentration of the liquid sample to be measured, and the cell 2a or 2b is positioned on the optical path. Then, measurement is performed in either cell 2a or 2b. That is, the cell 2 is moved up and down to switch so that the low concentration sample is measured in the cell 2a having a long optical path length and the high concentration sample is measured in the cell 2b having a short optical path length. Since the optical path length of the cell 2a is 10 times the optical path length of the cell 2b, the cell 2a is suitable for measuring a 1/10 low-concentration sample with respect to the cell 2b. Suitable for measuring samples of
[0018]
FIG. 2 shows an embodiment of a detection apparatus using the flow cell 2. A liquid sample is supplied to the flow cell 2 from the lower end inlet and discharged from the upper end outlet. The cell 2 is fixed to a cell vertical movement mechanism 10 corresponding to the first cell movement mechanism, and is moved and positioned in the vertical direction.
[0019]
Two lamps, a D2 lamp 12 and a halogen lamp 14, are provided as light sources. Lights from the lamps 12 and 14 are collected by condenser lenses 13a and 13b, respectively, and reflected by mirrors 16a and 16b to be collected. The light lenses 18 are arranged so as to be condensed on a common single optical path through different portions. Shutters 15a and 15b (see FIG. 3) are provided between the lamp 12 and the mirror 16a and between the lamp 14 and the mirror 16b, respectively, and only the light from one of the lamps 12 or 14 is obtained by opening and closing these shutters. The light can be introduced into the optical path for measurement, or the light from both lamps 12 and 14 can be introduced into the optical path for measurement at the same time. When the lights from both lamps 12 and 14 are always introduced simultaneously into the optical path for measurement, the shutters 15a and 15b are unnecessary. The light collected by the lens 18 is converted into parallel light by the lens 20 and irradiates the flow cell 2. The lamps 12 and 14, lenses 13a, 13b, 18, and 20, mirrors 16a and 16b, condenser lens 18, and shutters 15a and 15b constitute an irradiation optical system.
[0020]
The parallel light transmitted through the flow cell 2 is collected by the lens 22, introduced into the optical fiber 24, and guided to the spectroscope 26 through the optical fiber 24. The light guided to the spectroscope 26 is split in the spectroscope 26 and detected by a photodetector. The lens 22 light, the fiber 24, and the photodetector in the spectroscope 26 constitute a light receiving optical system.
[0021]
The flow cell 2 is moved by the cell vertical movement mechanism 10 so that the cell 2a is on the measurement optical path when the sample is a low concentration sample, and the cell 2b is on the measurement optical path when the sample is a high concentration sample. Positioned.
[0022]
FIG. 3 is an enlarged view of the irradiation optical system and the light receiving optical system. The flow cell 2 is disposed in a direction perpendicular to the paper surface, and the lamps 12 and 14 of the light receiving optical system are disposed in a horizontal plane so as to be aligned with each other. The lens 18 is arranged such that its optical axis is orthogonal to the straight line on which the lamps 12 and 14 are arranged. The mirrors 16a and 16b are configured so that the respective lights collected by the condenser lenses 13a and 13b are reflected by the mirrors 16a and 16b and condensed on the same optical path on the horizontal plane by using half of the lenses 18. Has been placed. Shutters 15a and 15b are provided between the lamp 12 and the mirror 16a and between the lamp 14 and the mirror 16b, respectively.
[0023]
FIGS. 4 to 7 show an embodiment of a detection apparatus in which a plurality of flow cells are arranged and sequentially switched and positioned on the optical path. 4 is a plan view of the entire detection apparatus, and FIG. 5 is a side view. 6 is a front view of the cell up / down moving plate 32 portion, and FIG. 7 is a front view of the cell left / right moving plate 30 portion.
[0024]
The light receiving optical system and the irradiation optical system are those shown in FIG. Flow cells 2-1 to 2-n are arranged in a line in the horizontal direction. As shown in FIG. 7, these flow cells 2-1 to 2-n are fixed to a cell left-right moving plate 30, and each cell 2-1 to 2-n flows from each analyzer or pipe. Connected to the road. The cell left / right moving plate 30 is supported by guide grooves 34a and 34b provided in the cell vertical moving plate 32 so as to be movable in the horizontal direction. The cell vertical movement plate 32 is provided with a cell horizontal movement mechanism 36 for moving the cell horizontal movement plate 30. The cell horizontal movement mechanism 36 has a pulse motor 38 and a ball screw 40 whose rotation is driven by the pulse motor. Is provided. A screw is formed at the lower end portion of the cell left / right moving plate 30, and the screw meshes with the ball screw 40. By rotating the ball screw 40 with the pulse motor 38, the cell left / right moving plate 30 is horizontally moved in the left / right direction. The predetermined flow cell can be positioned on the optical path at a predetermined position by being moved.
The cell left / right moving plate 30, the guide grooves 34a, 34b, the cell left / right moving mechanism 36, and the lower end screw of the cell left / right moving plate 30 constitute a second cell moving mechanism.
[0025]
Further, as shown in FIGS. 5 and 6, the cell vertical movement plate 32 is supported by a cell vertical movement support column 42 so as to be movable in the vertical direction. A cell vertical movement mechanism 46 is provided at 44. The cell vertical movement mechanism 46 includes a pulse motor 48 and a crankshaft 50 driven by the pulse motor 48. The cell vertical movement plate 32 is moved vertically by the crankshaft 50 and is arranged above and below each flow cell. One of the two cells 2a and 2b is positioned on the optical path for measurement. Reference numeral 52 denotes a hole provided in the cell vertical movement plate 32 to transmit measurement light.
The cell vertical movement plate 32, the cell vertical movement support column 42, and the cell vertical movement mechanism 46 constitute a first cell movement mechanism.
[0026]
In this detection device, a pipe from the analyzer or a pipe for introducing a factory waste liquid is connected to each flow cell 2-1 to 2-n, and a liquid sample is distributed. In order to select a predetermined flow cell and position it on the optical path for measurement, the cell left / right moving plate 30 is selected and moved by the pulse motor 38 of the cell left / right moving mechanism 36, and the cell is selected according to the concentration of the sample. The cell vertical movement plate 32 is moved in the vertical direction by the pulse motor 48 of the vertical movement mechanism 46, and the cell 2a or 2b is positioned on the optical path for measurement.
[0027]
FIG. 8 is a block diagram schematically showing an embodiment of the liquid sample measuring apparatus of the present invention. Reference numeral 60 denotes an embodiment of the detection apparatus according to the present invention as shown in FIG. 4 to FIG. 7, and is named a measurement apparatus main body here. A sample is supplied to the measuring device main body 60 through an analyzer or piping 62 and discharged through the flow cell of the measuring device main body 60. A detection signal obtained by the spectroscope of the measuring device main body 60 is introduced into a personal computer 64 as a data processing device and processed as a measurement result representing absorbance or further concentration. The personal computer 64 also controls the positioning of the flow cell, the wavelength scanning of the spectrometer, and the selection of the light source.
As the analyzer, for example, a liquid chromatograph or a dissolution tester is connected, and as a pipe or the like, a pipe for guiding a factory waste liquid or environmental water is connected.
[0028]
【The invention's effect】
In the flow cell used in the present invention, a plurality of cells having the same light transmission direction and different optical path lengths are integrated and arranged on one liquid sample channel, and the outer dimensions of those cells in the light transmission direction are the same. Therefore, by selecting a cell having an appropriate optical path length according to the concentration of the liquid sample, measurement can be performed over a wide concentration range. Also, since the external dimensions of those cells in the light transmission direction are the same, the sum of the optical path length in the liquid sample and the optical path length in the flow cell wall is the same, and the cell is switched. In addition, the concentration measurement can be performed with high accuracy. For example, it is possible to use a common calibration curve in cells having different optical path lengths, thereby facilitating calibration.
The detection apparatus and liquid sample measurement apparatus of the present invention provided with this flow cell not only have the advantages of this flow cell, but also the irradiation optical system includes a plurality of light sources having different wavelength characteristics as light sources, An optical system that totally reflects light with a mirror and guides it to the optical path using different parts of a common condensing lens can be used to enlarge the measurement wavelength region and facilitate adjustment of the optical axis. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a flow cell used in the present invention.
FIG. 2 is a schematic configuration diagram showing an embodiment of the detection apparatus of the present invention using the flow cell.
3 is an enlarged schematic plan view showing an irradiation optical system and a light receiving optical system in the embodiment of FIG. 2; FIG.
FIG. 4 is a plan view showing the whole of another embodiment of the detection apparatus of the present invention.
FIG. 5 is a side view of the embodiment.
FIG. 6 is a front view showing a cell vertical movement plate portion in the same embodiment.
FIG. 7 is a front view showing a cell left / right moving plate portion in the same embodiment.
FIG. 8 is a block diagram schematically showing an embodiment of the liquid sample measuring apparatus of the present invention.
[Explanation of symbols]
2,2-1 to 2-n Flow cell 2a, 2b Cell 10 Cell vertical movement mechanism 12 D2 lamp 14 Halogen lamps 13a, 13b, 18, 20, 22 Condensing lenses 15a, 15b Shutters 16a, 16b Mirror 24 Optical fiber 26 Spectroscopy Device 30 Cell left / right moving plate 32 Cell vertical moving plate 34a, 34b Guide groove 36 Cell left / right moving mechanism 38 Pulse motor 40 Ball screw 42 Cell vertical moving column 46 Cell vertical moving mechanism 48 Pulse motor 50 Crankshaft 60 Measuring device main body 62 Analyzer Or piping 64 personal computer

Claims (9)

A flow cell in which a plurality of cells having the same light transmission direction and different optical path lengths are integrated and disposed on one liquid sample channel, and the outer dimensions of those cells in the light transmission direction are the same,
An irradiation optical system that includes a light source and irradiates the flow cell with light from the light source as measurement light on a single optical path;
A light receiving optical system that receives and detects light transmitted through the flow cell;
Spectroscopic means provided in either the irradiation optical system or the light receiving optical system;
A first cell moving mechanism that selects and positions one of the plurality of cells in the flow cell on the optical path of the irradiation optical system,
The irradiation optical system includes a plurality of light sources having different wavelength characteristics as the light source , a common condensing lens for guiding light from the light sources to the single optical path as measurement light, and the plurality of light sources. A detection apparatus comprising an optical system comprising mirrors that totally reflect light and guide it to different portions of the condenser lens . The irradiation optical system is arranged so that the optical path for irradiating the flow cell is in a horizontal direction,
The flow cell is installed in a vertical direction so that a plurality of cells having different optical path lengths are arranged vertically,
The detection apparatus according to claim 1, wherein the first cell moving mechanism is a mechanism that positions the cell on the optical path of an irradiation optical system by moving the flow cell in a vertical direction. The detection apparatus according to claim 1, further comprising a second cell moving mechanism that includes a plurality of the flow cells, and selects any one of the flow cells and positions the flow cell on the optical path of the irradiation optical system. The plurality of flow cells are arranged in a horizontal direction along a vertical plane orthogonal to the optical path of the irradiation optical system,
The detection apparatus according to claim 3, wherein the second cell moving mechanism is a mechanism for positioning a predetermined flow cell on the optical path of an irradiation optical system by moving the flow cell in a horizontal direction. 5. The detection device according to claim 1, wherein the irradiation optical system further includes a shutter that selects light from any one of the light sources and introduces the light into the optical path. A liquid sample measurement device comprising: the detection device according to claim 1; and a sample supply mechanism that supplies a liquid sample to be measured to the detection device. The liquid sample measuring device according to claim 6, wherein the sample supply mechanism is an analyzer main body. The liquid sample measuring device according to claim 7, wherein the analyzer main body is a dissolution tester or a liquid chromatograph. The liquid sample measuring device according to claim 6, wherein the sample supply mechanism is a piping system that supplies a sample to be measured.

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