JP2015135251A - Solution analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solution analyzer capable of maintaining a sample temperature constant even when a sample flow rate is large, thereby making appropriate analysis of a sample to be measured possible.SOLUTION: In optically analyzing a sample flowing in a flow cell 2, a heat exchanger 1 for exchanging a heat of the sample is maintained at a constant temperature by a heat exchanger Peltier element 9 which is a heat exchanger temperature adjustment mechanism, and a measurement optical system 3 including the flow cell 2 is maintained at a constant temperature by a measurement optical system Peltier element 14 which is a measurement optical system temperature adjustment mechanism, so that, even when a sample flow rate is large, a sample temperature can be maintained constant, whereby appropriate analysis of the sample to be measured is made possible. Furthermore, due to that the heat exchanger 1 and the measurement optical system 3 are thermally separated, the measurement optical system 3 is made less susceptible to temperature fluctuations in the heat exchanger 1 when the sample flow rate is large.

Description

  The present invention relates to a solution analyzer that optically analyzes a sample (solution) flowing in a flow cell, and is suitable for a solution analyzer that analyzes a sample using, for example, fluorescence spectroscopy.

  In analysis of a sample by fluorescence spectroscopy, the sample is introduced into a flow cell, irradiated with light of a specific wavelength set in advance as excitation light, and the fluorescence of the excited sample is measured with a fluorescence detector. Measure the concentration of the component to be measured. At this time, some samples and components to be measured have large temperature dependence of fluorescence intensity. When the temperature of the sample fluctuates due to environmental temperature, the fluorescence detected by the measurement optical system such as a fluorescence detector Intensity fluctuates and proper analysis is not possible. Therefore, for example, in Patent Document 1 and Patent Document 2 below, heat exchange of the sample is performed with a heat exchanger before flowing into the flow cell, and a constant temperature control mechanism including the measurement optical system including the flow cell and the heat exchanger is used. Adjust to temperature. Specifically, the measurement optical system and the heat exchanger are brought into thermal contact with each other, and they are adjusted to a constant temperature by one temperature control mechanism. In Patent Document 2 below, the fluorescence detector is also adjusted to a constant temperature by the same temperature control mechanism.

JP 2000-346805 A JP 2008-256530 A

  When the flow rate of the sample is small, the temperature of the sample can be kept constant even if the measurement optical system and the heat exchanger are brought into thermal contact with each other and the temperature is adjusted at the same time as in Patent Document 1 and Patent Document 2 described above. Can do. However, in a process analyzer or the like, it is difficult to reduce the flow rate of the sample, or a certain degree of tube diameter and flow rate must be ensured in order to pass cleaning water. Generally, the amount of heat exchange increases as the flow rate of the sample in the heat exchanger increases, and the temperature of the heat exchanger varies due to the exchange heat. At this time, if the heat exchanger and the measurement optical system are in thermal contact, the temperature fluctuation of the heat exchanger is conducted to the measurement optical system and the temperature of the measurement optical system fluctuates. The accuracy cannot be made constant. When the temperature of the sample fluctuates, proper analysis cannot be performed.

  The present invention has been made to solve these various problems, and even when the flow rate of the sample is large, the temperature of the sample can be kept constant, thereby enabling appropriate analysis of the sample to be measured. The object is to provide a solution analyzer.

  In order to solve the above problems, a solution analyzer according to an aspect of the present invention is a solution analyzer that optically analyzes a sample flowing in a flow cell, the heat exchanger performing heat exchange of the sample, A temperature adjustment mechanism for a heat exchanger that makes the temperature of the heat exchanger constant, a measurement optical system that includes the flow cell, and a temperature adjustment mechanism for the measurement optical system that makes the temperature of the measurement optical system constant It is what.

In addition, temperature control means temperature control.
In this solution analyzer, it is desirable that the heat exchanger and the measurement optical system are thermally separated.
In this solution analyzer, it is preferable that the temperature adjustment mechanism for the heat exchanger and the temperature adjustment mechanism for the measurement optical system are Peltier elements.

Thus, according to the solution analyzer of the present invention, the heat exchanger for exchanging the heat of the sample is kept at a constant temperature by the temperature adjustment mechanism for the heat exchanger, and the measurement optical system including the flow cell is the temperature adjustment mechanism for the measurement optical system. Therefore, even if the flow rate of the sample is large, the temperature of the sample can be kept constant, and thus the sample to be measured can be appropriately analyzed.
In addition, by thermally separating the heat exchanger and the measurement optical system, the measurement optical system is less susceptible to the effects of temperature fluctuations of the heat exchanger when the flow rate of the sample is large, and the sample temperature is made more constant. Therefore, it is possible to appropriately analyze the sample to be measured.

  Moreover, a structure can be made easy by using a Peltier element for the temperature control mechanism for heat exchangers, and the temperature control mechanism for measurement optical systems.

It is a schematic block diagram which shows one Embodiment of the solution analyzer of this invention. It is explanatory drawing of sample temperature in case the flow volume of a sample is small in the solution analyzer of FIG. It is explanatory drawing of sample temperature when the flow volume of a sample is large in the solution analyzer of FIG.

  FIG. 1 is a schematic configuration diagram showing an embodiment of a solution analyzer of the present invention. The solution analyzer of this embodiment is in a state in which the heat exchanger 1 for keeping the temperature of the sample constant and the measurement optical system 3 including the flow cell 2 are thermally separated, specifically in a non-contact state. Provided, they are covered with a heat insulating material 4 and are respectively joined to the inner wall of the heat insulating material 4. A flow path 5 for introducing a sample from the outside of the heat insulating material 4 and sending the sample to the outside of the heat insulating material 4 is formed in series so as to pass from the heat exchanger 1 to the flow cell 2 in the measurement optical system 3. Yes.

  The flow path 5 is connected to the inside of the heat exchanger 1 from the upper side of the heat exchanger 1 in the figure, passes through the inside of the heat exchanger 1 so as to meander, and protrudes from the lower side of the heat exchanger 1 in the figure. The measurement optical system 3 is connected to the inside from the lower side of the drawing, passes through the flow cell 2 and protrudes from the upper side of the measurement optical system 3 in the drawing. Samples flow in this order within the solution analyzer. The flow path 5 between the heat exchanger 1 and the measurement optical system 3 is covered with a heat insulating tube 19 to minimize heat exchange that occurs between the sample passing through the interior and the internal space air of the heat insulating material 4. It is limited. As a material of the flow path 5, it is conceivable to use PTFE (polytetrafluoroethylene) or the like from the viewpoint of preventing sample contamination.

  In the measurement optical system 3, a flow cell holder 6 that holds the flow cell 2, a light source 7 that irradiates the flow cell 6 that is held by the flow cell holder 6 with excitation light of a specific wavelength, and fluorescence detection that detects fluorescence generated from the sample in the flow cell 6. A vessel 8 is provided. Although illustration is omitted in FIG. 1 for easy understanding, the light source 7 and the fluorescence detector 8 are configured to include a condensing mirror, a slit, an analysis grid, and the like, as is well known. Yes. In FIG. 1, the light source 7 and the fluorescence detector 8 are arranged on a straight line. However, the light source 7 and the fluorescence detector 8 are actually arranged at positions shifted from each other by 90 °. .

  As a material of the heat exchanger 1, it is conceivable to use, for example, an aluminum block having good thermal conductivity. The heat exchanger 1 is joined with a Peltier element 9 for heat exchanger as a temperature control mechanism for the heat exchanger, and the Peltier element 9 for heat exchanger is attached to the wall portion of the heat insulating material 4 to which the heat exchanger 1 is joined. Buried. As is well known, the Peltier element is a semiconductor element that can heat or cool the surface to which the heat exchanger 1 is bonded in accordance with the direction of the applied current, for example, in this embodiment. Also called an element. A heat exchanger radiating fin 10 is joined to the outer surface of the heat exchanger Peltier element 9 exposed on the outer wall surface of the heat insulating material 4, and the heat exchanger radiating fan 10 is opposed to the heat exchanger radiating fin 10. 11 is arranged.

  A heat exchanger temperature sensor 12 for detecting the temperature of the heat exchanger 1 itself is attached to the heat exchanger 1, and its output is input to the heat exchanger control circuit 13. As this heat exchanger temperature sensor 12, it is conceivable to use a platinum resistor, a thermocouple, a thermistor, or the like. The heat exchanger control circuit 13 controls the current applied to the Peltier element 9 for the heat exchanger based on the temperature of the heat exchanger 1 detected by the temperature sensor 12 for the heat exchanger, and the heat radiating fan 11 for the heat exchanger. The operating state is controlled so that the temperature of the heat exchanger 1 is maintained at a preset constant temperature. As a result, the temperature of the sample can be adjusted to a preset constant temperature or a constant temperature region at the outlet from the heat exchanger 1 in the flow path 5.

  In the present embodiment, a measurement optical system Peltier element 14 as a temperature adjustment mechanism for the measurement optical system is joined to the measurement optical system 3, and the measurement optical system Peltier element 14 is a heat insulation to which the measurement optical system 3 is joined. It is embedded in the wall portion of the material 4. The measurement optical system Peltier element 14 only needs to be bonded to any of the constituent members of the measurement optical system 3, and is bonded to the flow cell holder 6 in this embodiment. As a material of the flow cell holder 6, for example, it is conceivable to use an aluminum block having good thermal conductivity. Further, as the material of the flow cell 2 held by the flow cell holder 6, it is conceivable to use quartz or the like that has excellent light transmission and good thermal conductivity.

  A measurement optical system radiation fin 15 is joined to the outer surface of the measurement optical system Peltier element 14 exposed on the outer wall surface of the heat insulating material 4, and the measurement optical radiation fan 15 faces the measurement optical radiation fin 15. 16 is arranged. The flow cell holder 6 is provided with a measurement optical system temperature sensor 17 for detecting the temperature of the flow cell holder 6 itself, and its output is input to the measurement optical system control circuit 18. As the measurement optical system temperature sensor 17, a platinum resistor, a thermocouple, a thermistor, or the like may be used in the same manner as the heat exchanger temperature sensor 12. The measurement optical system control circuit 18 controls the current applied to the measurement optical system Peltier element 14 based on the temperature of the flow cell holder 6 detected by the measurement optical system temperature sensor 17 and also dissipates the measurement optical system heat. The operating state of the fan 16 is controlled so that the temperature of the flow cell holder 6 is maintained at a predetermined constant temperature. As a result, the temperature of the sample can be adjusted to a preset constant temperature or a constant temperature region at the sample measurement position in the flow cell 2.

  The sample that has been adjusted to a preset constant temperature or a constant temperature region and has reached the sample measurement position of the flow cell 2 in this manner is irradiated with excitation light of a specific wavelength from the light source 7, and the fluorescence is detected by the fluorescence detector 12. Detected. Since the temperature of the sample is a constant temperature or a constant temperature region, the fluorescence intensity detected by the fluorescence detector 12 accurately reflects the component concentration of the sample, and the component concentration of the sample is properly detected from the detected fluorescence intensity. It becomes possible to do.

  FIG. 2 is an explanatory diagram of sample temperature when the sample flow rate is small in the solution analyzer of FIG. 1, and FIG. 3 is an explanatory diagram of sample temperature when the sample flow rate is large in the solution analyzer of FIG. In both cases, the horizontal axis indicates the sample flow direction position, the vertical axis indicates the temperature, and the allowable range of the set temperature of the sample at the measurement position is shaded. Further, the temperature change of the high temperature sample is indicated by a solid line, and the temperature change of the low temperature sample is indicated by a broken line. As shown in FIG. 2, when the flow rate of the sample is small, the temperature of the sample is within the allowable range before reaching the outlet of the heat exchanger 1, and, of course, also within the allowable range at the measurement position. ing. On the other hand, as shown in FIG. 3, when the flow rate of the sample is large, the temperature of the sample is not within the allowable range until it reaches the outlet of the heat exchanger 1. However, in this embodiment, since the temperature of the measurement optical system 3 is adjusted by the measurement optical system Peltier element 14, the temperature of the sample changes even after flowing into the flow cell holder 6, and the temperature of the sample at the measurement position is It is within the allowable range. From this, in the solution analyzer of this embodiment, the component concentration of a sample can be detected appropriately and an analysis result with high reproducibility can be obtained.

  As described above, in the solution analyzer of this embodiment, the heat exchanger 1 that performs heat exchange of the sample is set to a constant temperature by the Peltier element 9 for heat exchanger that is a temperature control mechanism for the heat exchanger, and includes a measurement optical system including the flow cell 2. 3 is set to a constant temperature by the measurement optical system Peltier element 14 which is a temperature control mechanism for the measurement optical system, so that the temperature of the sample can be made constant even when the flow rate of the sample is large, and the object to be measured Proper analysis of the sample becomes possible.

Further, by thermally separating the heat exchanger 1 and the measurement optical system 3, the measurement optical system 3 becomes less susceptible to the influence of temperature fluctuations of the heat exchanger 1 when the flow rate of the sample is large. Can be made even more constant, so that it is possible to appropriately analyze the sample to be measured.
Further, by using Peltier elements for the heat exchanger temperature control mechanism and the measurement optical system temperature control mechanism, the configuration can be made easier as compared with the case of using a heater or a refrigeration cycle.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Flow cell 3 Measurement optical system 4 Heat insulating material 5 Flow path 6 Flow cell holder 7 Light source 8 Fluorescence detector 9 Peltier device for heat exchanger (Temperature control mechanism for heat exchanger)
DESCRIPTION OF SYMBOLS 10 Heat dissipation fin for heat exchanger 11 Heat dissipation fan for heat exchanger 12 Temperature sensor for heat exchanger 13 Control circuit for heat exchanger 14 Peltier element for measurement optical system (temperature control mechanism for measurement optical system)
15 Radiation fin for measurement optical system 16 Radiation fan for measurement optical system 17 Temperature sensor for measurement optical system 18 Control circuit for measurement optical system 19 Insulation tube

Claims (3)

A solution analyzer for optically analyzing a sample flowing in a flow cell,
A heat exchanger for heat exchange of the sample;
A temperature adjustment mechanism for a heat exchanger that makes the temperature of the heat exchanger constant;
A measurement optical system including the flow cell;
A temperature control mechanism for the measurement optical system that makes the temperature of the measurement optical system constant;
A solution analyzer comprising:   The solution analyzer according to claim 1, wherein the heat exchanger and the measurement optical system are thermally separated.   The solution analyzer according to claim 1 or 2, wherein the temperature adjustment mechanism for the heat exchanger and the temperature adjustment mechanism for the measurement optical system are Peltier elements.

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