JP5358466B2 - Liquid chromatograph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid chromatograph device capable of keeping a heat quantity generated from a light source in a constant state even if a room temperature is fluctuated, and suppressing fluctuation of a base line of a detection signal. <P>SOLUTION: The device includes: a fan provided on a detector for detecting a sample component, for sending air to a light source unit for irradiating the component with light; a temperature sensor for measuring the temperature of the air; a heat exchanger for exchanging heat with the air; and a control unit for controlling the heat exchanging amount exchanged with the air by the heat exchanger based on a rotational frequency of the fan and the temperature of the air measured by the temperature sensor. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a liquid chromatograph apparatus.

  A liquid chromatograph device circulates a liquid containing a sample in a cylindrical tube filled with microparticles called a column, and the sample is separated or purified into a target component when passing through the column. It is an apparatus which detects using the optical means.

  The liquid chromatograph was separated and purified by a pump for feeding the liquid, a sampler for introducing the sample into the liquid, a column oven for holding the column in a constant temperature atmosphere, and the column. It consists of a detector for detecting the target component of the sample. Each component connects piping in the order of pump, sampler, column, and detector. The liquid sent from the pump is usually called a mobile phase. The sample introduced from the sampler contains multiple components, and these components are separated by the column and pass through the detector at different times. Therefore, in the detector, the concentration of the target component contained in the mobile phase Changes are detected using optical means.

  As a detector for a liquid chromatograph apparatus, a UV detector that measures absorbance by ultraviolet light is widely used. In the UV detector, a deuterium lamp that emits ultraviolet light including light having a wavelength of 190 to 400 nanometers is used as a light source. A UV detector generally performs detection as follows. First, ultraviolet light emitted from a deuterium lamp is dispersed by a grating. Only light having a specific wavelength is extracted from the split light through a slit. The extracted light of a specific wavelength is collected by a lens, a curved mirror, etc., and irradiated to the flow path in which the mobile phase flows. The flow path irradiated with this light is called a flow cell. The light transmitted through the flow cell is received by a photosensor and converted into an electrical signal. Since the intensity of the transmitted light passing through the flow cell depends on the concentration of the target component contained in the mobile phase flowing through the flow cell, the concentration of the target component passing through the flow cell is the final intensity of the electrical signal in the photocell. Detected.

  In addition to the UV detector, there is a diode array detector as a detector for detecting a target component with light. The UV detector irradiates the flow cell with the dispersed light and measures the absorbance at each wavelength, while the diode array detector irradiates the flow cell with light that contains the unspectrulated multi-wavelength component, The transmitted light is dispersed by a grating and detected for each wavelength by a photodiode array detector composed of a plurality of photodiodes. The diode array detector has an advantage that a plurality of wavelengths can be detected simultaneously.

  In the UV detector and the diode array detector, the deuterium lamp described above and a tungsten lamp that emits light in the visible light region are used as a light source. Since deuterium lamps and tungsten lamps generate heat, heat is applied to the surrounding optical components and structures constituting the optical system. When heat is transmitted to the optical component or the optical system structure and the temperature rises, the optical characteristics change, and the detection signal intensity varies. This variation results in a baseline variation, which is the signal strength detected when no signal component is included, reducing the detection capability of the detector. Therefore, conventionally, an attempt has been made to remove the influence of such a temperature rise by cooling the light source. In the exhaust heat system by air cooling, the air cooling efficiency varies depending on the surface area, air volume, air temperature, etc. of the air-cooled part. Since the air cooling mechanism takes in air around the apparatus and performs air cooling, the temperature of the air used for air cooling is linked to the environmental temperature where the apparatus is installed, for example, room temperature. That is, the efficiency of air cooling changes with room temperature. As a result, the temperature of the optical system constituent material changes in conjunction with the room temperature, and the baseline of the detection signal also changes in conjunction with the room temperature. Baseline fluctuations in the detection signal are detrimental to high-sensitivity analysis and quantitative analysis. Thus, a technique for controlling the operation of the cooling fan in accordance with the room temperature has been proposed (see, for example, Patent Document 1).

JP 2007-064632 A

  In the above-described method of controlling the operation of the cooling fan based on the fluctuation of the room temperature, which is the temperature of the cooling air, the amount of heat generated by the light source is made constant, and the difference from the amount of heat that does not affect the surrounding optical system is cooled. The air volume is set to be removed by the wind. Therefore, when there is a change in room temperature, the air volume of the cooling air also changes accordingly.

  However, after detecting the room temperature, the rotation speed of the cooling fan is changed and the light source is cooled by changing the air volume of the cooling air, so there is a time delay between the change in the room temperature and the amount of heat generated by the light source. Since some influence of heat on the optical system is inevitable, the baseline of the detection signal is changed although it is small, and the detection accuracy is lowered.

  An object of the present invention is to provide a liquid chromatograph that can keep the amount of heat generated by a light source constant even when there is a change in room temperature, and can suppress a change in the baseline of a detection signal.

  In order to solve the above-described problems, the embodiment of the present invention includes a device that keeps the temperature of air introduced by the cooling fan constant, and obtains in advance the amount of heat to be removed from the amount of heat generated by the light source. The air volume and temperature to be set are set as target values for control.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid chromatograph apparatus which can maintain the calorie | heat amount which generate | occur | produces with a light source uniformly even if there exists a fluctuation | variation of room temperature, and can suppress the fluctuation | variation of the baseline of a detection signal can be provided.

The longitudinal cross-sectional view which shows the outline of a liquid chromatograph apparatus. The longitudinal cross-sectional view which shows the outline of a liquid chromatograph apparatus. The longitudinal cross-sectional view which shows the outline of a liquid chromatograph apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

〔Example〕
A first embodiment of the present invention will be described. FIG. 1 is a longitudinal sectional view showing an outline of a liquid chromatograph apparatus. In the liquid chromatograph apparatus 100, a light source unit 101 containing a light source and a spectroscope 102 that performs light detection using light emitted from the light source. And a fan 103 for air-cooling the light source unit 101 and a duct 104 for guiding the wind of the fan 103 to the light source unit 101 are installed. First, a case where the temperature sensor 105 is not provided will be described.

  A heater 106 is provided in the duct 104 to exchange heat with air flowing in the duct. For example, a heating wire can be used as the heater 106. When the temperature of the outside air taken into the fan 103 is lower than the temperature of the heater 106 and the outside air is heated by the heater 106 and supplied to the light source unit 101 for cooling, the outside air does not exceed the temperature of the heater 106. The control by the measurement of the temperature sensor 105 is unnecessary, and therefore the temperature sensor 105 is not provided. If the temperature of the air heated by the heater 106 is lower than the temperature of the light source unit 101, the light source unit 101 is cooled. Therefore, by keeping the temperature of the heater 106 constant, air having a constant temperature can be supplied to the light source unit 101 for cooling.

  Next, the control when the temperature sensor 105 for measuring the temperature of the ambient air taken into the fan 103 is installed will be described. The temperature of the air blown to the light source unit 101 is determined by the temperature of the air taken in by the fan 103 and the amount of heat exchange performed when the air passes through the heater 106. If the air volume of air is constant, the temperature of air striking the light source unit 101 can be kept constant by changing the heat exchange amount according to fluctuations in the temperature of air. Therefore, if the amount of heat generated from the light source is constant and the flow rate and temperature of the air that cools the light are constant, a certain amount of heat can always be removed from the light source. The above control is performed by a processor provided in the control unit 107. With the above configuration, the light source unit 101 can be kept at a constant temperature, so that fluctuations in the baseline of the detection signal can be suppressed.

  The fact that heat is not transferred from the light source unit 101 to the surrounding optical system is a reference for obtaining the heat exchange amount. If the amount of heat generated by the light source unit 101 cannot be kept constant only by the amount of heat exchange by the heater 106, the control unit 107 performs adjustment by changing the rotational speed of the fan 103.

  FIG. 2 is a longitudinal sectional view showing an outline of the liquid chromatograph apparatus, in which a temperature sensor 201 and a control unit 202 are further provided with respect to the liquid chromatograph apparatus 100 shown in FIG.

  The amount and temperature of air given to the light source unit 101, that is, the amount of heat, is a predetermined constant amount. Therefore, if the flow rate of air introduced by the fan 103 is constant, the temperature sensor 201 introduces it into the light source unit 101. By measuring the temperature of the air immediately before being performed, the amount of heat exchanged by the heater 106 can be calculated and controlled by the processor of the control unit 202. The amount of heat exchanged by the heater 106 can be replaced with the temperature of a heat exchange medium such as hot water flowing through the heater 106 by obtaining the air volume, inlet air temperature, and outlet air temperature in advance.

  The input signal of the control unit 202 is the rotation speed of the fan 103 and the temperature of the air measured by the temperature sensor 201, and the output signal is the amount of heat exchanged by the heater 106 or the temperature of the heat exchange medium.

  If the temperature sensor does not measure the room temperature at which the air is taken in by the fan 103, but measures the temperature of the air at the introduction part to the light source unit 101 as in this embodiment, the light source unit 101 Since the heat quantity of the air given to is directly measured, the calculation in the control unit 202 is simplified. Furthermore, it is not necessary to consider the temperature change of the air from the fan 103 to the outlet of the heater 106 as compared to when measuring the room temperature.

  FIG. 3 is a longitudinal sectional view showing an outline of the liquid chromatograph apparatus, in which a heat sink 301 is provided in place of the heater 106 with respect to the liquid chromatograph apparatus 100 shown in FIG.

  If the room temperature is high enough to cause insufficient cooling with respect to the amount of heat generated by the light source, it is necessary to stop heating the air by the heater 106 and increase the rotation speed of the fan 103 to increase the amount of air. However, when the cooling is insufficient only by increasing the amount of air, the configuration shown in FIG. 1 cannot cope. Therefore, the light source unit 101 is cooled by providing a heat sink 301 using Peltier as a heat source and lowering the temperature of the air introduced into the light source unit 101 below room temperature. As in the embodiment shown in FIG. 2, the temperature control of the air is performed by the heat sink 301 based on the temperature of the air sent from the temperature sensor 201 by the control unit 302 by providing the temperature sensor 201 at the air inlet of the light source unit 101. Control the amount of heat exchange.

  Further, when the cooling by the heat sink 301 is insufficient, the control unit 302 adjusts to increase the air volume by increasing the rotation speed of the fan 103.

  With the above configuration, the light source unit 101 can always be given a constant temperature or a constant amount of air, so that the amount of heat generated by the light source can be kept constant even when the room temperature varies, and the baseline of the detection signal can be varied. A liquid chromatograph apparatus that can be suppressed can be provided.

DESCRIPTION OF SYMBOLS 101 Light source unit 102 Spectrometer 103 Fan 104 Duct 105, 201 Temperature sensor 106 Heater 107, 202, 302 Control unit 301 Heat sink

Claims (8)

A column for separating the sample components;
A light source unit that emits light to the component;
In a liquid chromatograph apparatus comprising a spectrometer that detects a component based on light irradiated to the component,
A fan for blowing air to the light source unit;
A duct for guiding the air as a flow path of the air from the fan to the light source unit;
A heat exchanger provided in the middle of the duct for exchanging heat with the air;
The liquid chromatograph apparatus, wherein the air sent by the fan is heated to the temperature of the heat exchanger and sent to the light source unit. The description of claim 1, further comprising:
A temperature sensor for measuring the temperature of the air;
A liquid comprising: a rotation speed of the fan; and a control unit for controlling a heat exchange amount exchanged with the air by the heat exchanger based on a temperature of the air measured by the temperature sensor. Chromatographic device. In the description of claim 2,
The amount of heat exchange is
The liquid chromatograph apparatus is controlled by controlling a temperature of a heat medium of the heat exchanger. In the description of claim 2,
Furthermore, the liquid chromatograph apparatus which controls the rotation speed of the said fan. In the description of claim 2,
The temperature sensor is
A liquid chromatograph apparatus that is provided in the fan and measures the temperature of air taken into the fan. In the description of claim 2,
The temperature sensor is
A liquid chromatograph apparatus for measuring a temperature of air introduced into the light source unit. In the description of claim 2,
The liquid chromatograph apparatus, wherein the control unit controls a temperature of air introduced into the light source unit to be lower than a temperature of air around the fan. In the description of claim 2,
The liquid chromatograph apparatus, wherein the control unit controls a temperature of air introduced into the light source unit to be lower than a temperature of air around the fan.

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