Detector for liquid chromatograph

Abstract

To provide a detector for liquid chromatograph that facilitates lamp replacing work and suppresses the baseline of a detector signal from varying due to fluctuation in environmental temperature.SOLUTION: A detector for liquid chromatograph comprises: a lamp house 6; a lamp which has a light-emitting part 16 and a base end part 18 where a lead wire from the light-emitting part is led out, the light-emitting part being housed in the lamp house; a housing 2 which has an inner space and air vents 24, 32 for taking the outside air into the inner space and exhausting the air from the inner space; a fan 12 for forming a flow of the air in the inner space of the housing; and a heater 10 for heating the air taken into the inner space of the housing. The detector for liquid chromatograph is so configured that the air flowing in the inner space of the housing is heated by the heater before passing through the base end part 8 of the lamp 8.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a detector for liquid chromatography, such as an absorbance detector. [Background technology]

[0002] An absorbance detector, which is a detector for liquid chromatography, detects and quantifies components contained in a sample flowing through a cell by irradiating light emitted from a lamp onto the cell in which the sample flows and measuring the intensity of light of a specific wavelength transmitted through the cell. It is known that the emission intensity of a lamp is temperature dependent. If the temperature of the lamp fluctuates due to the influence of the environmental temperature, the intensity of the light irradiated onto the cell fluctuates, causing the baseline of the detector signal to fluctuate, making it impossible to obtain accurate analysis results. For this reason, it is common to attach a heater and a temperature sensor to the lamp house that houses the lamp to control the temperature of the lamp house to a constant value so that the temperature of the lamp is not affected by fluctuations in the environmental temperature (see Patent Document 1).

[0003] Incidentally, a lamp for a liquid chromatograph detector has a light-emitting part that emits light, and a base end part from which lead wires are drawn out from the light-emitting part. Lamps are consumable items that deteriorate over time and must be replaced when the deterioration progresses. Therefore, in order to facilitate the work of replacing lamps, a structure is sometimes adopted in which the lamp is fixed to the lamp house with the light-emitting part inserted from the outside of the lamp house into the lamp house (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 016846 [Patent Document 2] Patent No. 4269997 Summary of the Invention [Problem to be solved by the invention]

[0005] It has been found that in a detector having a structure that allows easy lamp replacement as described above, even if a heater and temperature sensor are attached to the lamp house to control the temperature of the lamp house, when the environmental temperature changes suddenly, the baseline of the detector signal may fluctuate before the temperature fluctuation of the lamp house is detected by the temperature sensor.

[0006] The present invention has been made in consideration of the above problems, and aims to suppress fluctuations in the baseline of the detector signal due to fluctuations in environmental temperature while adopting a structure that facilitates lamp replacement work. [Means for solving the problem]

[0007] In the above-mentioned structure that allows easy lamp replacement, the base end of the lamp is exposed to the outside of the lamp house, and even if the temperature of the lamp house is controlled to a constant value, the temperature of the base end of the lamp and the lead wires are likely to fluctuate. The inventors have found through their investigations that the reason why the baseline of the detector signal fluctuates due to changes in the environmental temperature, even though the temperature of the lamp house is controlled, is because the outside air taken into the housing passes over the base end of the lamp at the same temperature, fluctuating the temperature of the base end of the lamp. The present invention is based on this finding.

[0008] That is, the liquid chromatograph detector of the present invention comprises a lamp house, a lamp having a light-emitting unit that emits light and a base end from which lead wires from the light-emitting unit are pulled out, the light-emitting unit being contained inside the lamp house and the base end being attached to the lamp house with the light-emitting unit exposed to the outside of the lamp house, a housing that has an internal space and an air vent for taking in outside air into the internal space and exhausting air from the internal space, and that houses the lamp house in the internal space such that the lamp house and the base end of the lamp are positioned on the circulation path of air flowing through the internal space, a fan for forming an air flow in the internal space of the housing, and a heater for heating the air taken in to the internal space of the housing, and is configured so that the air flowing through the internal space of the housing is heated by the heater before passing through the base end of the lamp. Effect of the Invention

[0009] According to the liquid chromatograph detector of the present invention, the base end of the lamp exposed to the outside of the lamp house is arranged in the circulation path of the air flowing through the internal space of the housing, and the air flowing inside the housing is heated by the heater before passing through the base end of the lamp, so that the outside air taken into the housing does not pass through the base end of the lamp at its original temperature, and the temperature of the base end of the lamp is less susceptible to changes in the environmental temperature. As a result, while adopting a structure that makes it easy to replace the lamp, it is possible to suppress fluctuations in the baseline of the detector signal due to fluctuations in the environmental temperature. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic internal configuration diagram showing one embodiment of a liquid chromatograph detector. [Diagram 2] FIG. 2 is a diagram for explaining the structure of a lamp. [Diagram 3] FIG. 2 is a schematic diagram showing a control system according to the embodiment. [Figure 4] FIG. 11 is a schematic internal configuration diagram showing another embodiment of a liquid chromatograph detector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a liquid chromatograph detector according to the present invention will be described with reference to the drawings.

[0012] FIG. 1 shows an embodiment of a liquid chromatograph detector (hereinafter, simply referred to as a detector).

[0013] The detector 1 includes a housing 2, a spectroscope 4, a lamp house 6, a lamp 8, a heater 10, a fan 12, and a temperature sensor 14. The spectroscope 4, the lamp house 6, the lamp 8, the heater 10, the fan 12, and the temperature sensor 14 are accommodated in the internal space of the housing 2.

[0014] 1, the left side is the front side and the right side is the back side of the housing 2. An openable front panel 30 is provided on the front side of the housing 2, and ventilation holes 32 are provided at the top and bottom of the front panel 30. A ventilation hole 24 is provided at the top of the back side of the housing 2.

[0015] A flow cell, a light receiving element, etc. are provided inside the spectrometer 4 (not shown). The lamp house 6 is disposed on top of the spectrometer 4. The lamp house 6 is a metal member, with a cavity provided in the lower part for accommodating the light emitting part 16 of the lamp 8 and a fin structure on the upper part. Light emitted from the light emitting part 16 of the lamp 8 attached to the lamp house 6 is taken into the inside of the spectrometer 4 and guided to the flow cell, and the light that has passed through the flow cell or the light emitted from the sample in the flow cell is guided to the light receiving element.

[0016] Here, the structure of the lamp 8 will be described with reference to Fig. 2. The lamp 8 has a structure in which an electrode portion 17 is accommodated inside a glass tube 15, and a lead wire 20 for electrical conduction with the electrode portion 17 is drawn out from the base end (the left end in the figure) of the glass tube 15. A flange portion 22 is provided on the base end side of the glass tube 15. The portion on the tip side (the right side in the figure) of the flange portion 22 constitutes the light-emitting portion 16. The portion on the base end side (the left side in the figure) of the flange portion 22 is referred to as the base end portion 18. The electrode portion 17 is accommodated inside the light-emitting portion 16, and the light-emitting portion 16 emits light when a current is passed through the electrode portion 17 via the lead wire 20.

[0017] 1, the flange portion 22 of the lamp 8 is screwed to the outer surface of the lamp house 6 facing the front panel 30 of the housing 2, so that the light-emitting portion 16 is housed inside the lamp house 6 and the base end portion 16 is exposed to the outside of the lamp house 6 facing the front panel 30 of the housing 2. This structure makes it easy to open the front panel 30 of the housing 2 and to attach and detach the lamp 8 to and from the lamp house 6, i.e., to replace the lamp 8.

[0018] The heater 10 is attached to the lamp house 6 and heats the lamp house 6. The fan 12 is provided on the rear side of the housing 2 so as to take in outside air from the vent 24 and send it to the front side. The air sent by the fan 12 to the front panel 30 passes through the duct 26 and the fin structure at the top of the lamp house 6, passes through a space 28 on the front side inside the housing 2, and is exhausted to the outside of the housing 2 from the vent 32. The base end 18, the lead wires 20, and the flange portion 22 of the lamp 8 are present in the space 28, and the air indirectly heated by the heater 10 through the lamp house 6 by passing through the lamp house 6 passes through the base end 18, the lead wires 20, and the flange portion 22 of the lamp 8, and the base end 18, the lead wires 20, and the flange portion 22 of the lamp 8 are heated.

[0019] The temperature sensor 14 is provided in the space 28 near the base end 18, the lead wires 20, and the flange portion 22 of the lamp 8. The temperature sensor 14 detects the temperature of the air indirectly heated by the heater 10 via the lamp house 6.

[0020] 3, the detector 1 includes a control unit 100 that controls the output of the temperature sensor 14 and the fan 12. The control unit 100 controls the output of the heater 10 and the fan 12 so that the temperature detected by the temperature sensor 14 is maintained constant at a set temperature. The temperature detected by the temperature sensor 14, i.e., the temperature of the air passing through the base end 18, lead wire 20, and flange portion 22 of the lamp 8, is maintained constant, thereby maintaining the temperatures of the base end 18, lead wire 20, and flange portion 22 of the lamp 8 constant.

[0021] In this embodiment, the output of the heater 10 and the fan 12 is not controlled based on the temperature of the lamp house 6, but the temperature of the air indirectly heated by the heater 10 via the lamp house 6 is controlled to a constant temperature, thereby stabilizing the temperature of the lamp house 6 and, as a result, stabilizing the temperature of the light-emitting portion 16 of the lamp 8.

[0022] As described above, in the detector 1 of this embodiment, the temperatures of not only the light-emitting part 16 of the lamp 8 but also the base end 18, lead wire 20 and flange part 22 are maintained constant by controlling the output of the heater 10 and fan 12 based on the temperature detected by the temperature sensor 14. Therefore, the light emission intensity of the light-emitting part 16 is less susceptible to the influence of the environmental temperature compared to a case in which the outside air taken into the housing 2 passes through the base end 18, lead wire 20 and flange part 22 of the lamp 8 at the same temperature, and fluctuations in the baseline of the detector signal caused by fluctuations in the environmental temperature are suppressed.

[0023] Although the ventilation hole 32 is provided in the front panel 30 in the above embodiment, the ventilation hole 32 may be provided in any position such as a side surface, upper surface, or lower surface close to the front panel 30 of the housing 2, as long as the air that has passed through the lamp house 6 is exhausted to the outside of the housing 2 after passing through the base end portion 18, the lead wires 20, and the flange portion 22. By providing the ventilation hole 32 in a position other than the front panel 30, it is possible to prevent the air that has been heated by passing through the lamp house 6 from being exhausted to the front side of the housing 2.

[0024] Furthermore, in the above embodiment, the heater 10 is attached to the lamp house 6, but the present invention is not limited to this, and the heater may be attached to any position as long as it is possible to heat the air before it passes through the base end 18 of the lamp 8, the lead wires 20, and the flange portion 22.

[0025] FIG. 4 shows another embodiment of the detector.

[0026] In the detector 1' shown in Fig. 4, a heater 10' is provided at the vent 32 of the front panel 30 of the housing 2, and a fan 12' is provided to form an air flow inside the housing 2 such that outside air is taken in through the vent 32 and exhausted through the vent 24. The air taken into the housing 2 from the vent 32 is heated by the heater 10', passes through the base end 18 of the lamp 8, the lead wire 20, and the flange 22, then passes through the fin structure at the top of the lamp house 6, and is exhausted from the vent 24 through the duct 26. In other words, the base end 18 of the lamp 8, the lead wire 20, and the flange 22 are provided downstream of the heater 10' on the path of the air flowing inside the housing 2.

[0027] The temperature sensor 14 is provided to detect the temperature of air taken into the housing 2 through the ventilation opening 32 and heated by the heater 10'. The outputs of the heater 10' and the fan 12' are controlled so that the temperature detected by the temperature sensor 14 remains constant at a set temperature. With this configuration, the temperature of the air passing through the base end 18, the lead wires 20 and the flange portion 22 of the lamp 8 and further through the lamp house 6 is controlled to be constant, and as a result, the temperatures of the lamp house 6, the base end 18, the lead wires 20 and the flange portion 22 of the lamp 8 are maintained constant, and the light emission intensity from the light emitting portion 16 of the lamp 8 is stabilized.

[0028] The detectors 1 and 1' described above are merely examples of embodiments of the liquid chromatograph detector according to the present invention. The embodiments of the liquid chromatograph detector according to the present invention are as follows.

[0029] In one embodiment of the liquid chromatograph detector according to the present invention, the detector comprises a lamp house, a lamp having a light-emitting unit that emits light and a base end from which lead wires from the light-emitting unit are pulled out, the light-emitting unit being contained inside the lamp house and the base end being attached to the lamp house with the light-emitting unit exposed to the outside of the lamp house, a housing that contains the lamp house in the internal space such that the lamp house and the base end of the lamp are positioned on the flow path of air flowing through the internal space, a fan that forms an air flow in the internal space of the housing, and a heater that heats the air that is taken into the internal space of the housing, wherein the air flowing through the internal space of the housing is heated by the heater before passing through the base end of the lamp.

[0030] In a first aspect of the above embodiment, the lamp further includes a temperature sensor disposed at a position for detecting the temperature of the air heated by the heater, and a control unit for controlling the output of the fan and / or the heater so that the temperature detected by the temperature sensor becomes a set temperature. This controls the temperature of the air passing through the base end of the lamp to be constant, thereby stabilizing the temperature of the base end of the lamp and stabilizing the emission intensity of the lamp.

[0031] In a second aspect of the embodiment, the heater is provided to directly heat the lamp house while being in thermal contact with the lamp house, and the fan is provided to make air flowing through the internal space pass through the lamp house before the base end of the lamp. This second aspect can be combined with the first aspect.

[0032] In a third aspect of the embodiment, the heater is provided near the vent of the housing that functions as an intake port for taking air into the internal space. This third aspect can be combined with the first aspect.

[0033] In a fourth aspect of the embodiment, the base end of the lamp is disposed downstream of the heater in a flow path of air flowing through the internal space. [Explanation of symbols]

[0034] 1,1' detector 2. Chassis 4 Spectrometer 6. Lamp House 8 light source 10,10' Heater 12,12' Fan 14 Temperature Sensor 15 Glass tube 16 Light emitting part 17 Electrode part 18 Proximal end 20 Lead Wire 22 Flange 24,32 Vent 26 Duct 28 Space 30 Front Panel 100 Control section

Claims

1. Lamphouse and a lamp having a light-emitting portion that emits light and a base end portion from which a lead wire is drawn from the light-emitting portion, the light-emitting portion being accommodated inside the lamp house and the base end portion being attached to the lamp house in a state where it is exposed to the outside of the lamp house; a housing having an internal space and an air vent for taking in outside air into the internal space and discharging air from the internal space, the housing housing containing the lamp house in the internal space such that the lamp house and the base end of the lamp are positioned on a flow path of air flowing through the internal space; a fan for forming an air flow in the internal space of the housing; a heater for heating air taken into the internal space of the housing; A liquid chromatography detector configured so that air flowing through the internal space of the housing is heated by the heater before passing through the base end of the lamp.

2. a temperature sensor provided at a position to detect the temperature of the air heated by the heater; 2. The liquid chromatograph detector according to claim 1, further comprising a control unit that controls an output of the fan and / or the heater so that the temperature detected by the temperature sensor becomes a set temperature.

3. the heater is provided to directly heat the lamp house while being in thermal contact with the lamp house; 2. The liquid chromatograph detector according to claim 1, wherein the fan is provided so that air flowing through the internal space passes through the lamp house before passing through the base end of the lamp.

4. 2. The liquid chromatograph detector according to claim 1, wherein the heater is provided near the vent hole of the housing which functions as an intake hole for introducing air into the internal space.

5. 5. The liquid chromatograph detector according to claim 1, wherein the base end of the lamp is disposed downstream of the heater in a flow path of air flowing through the internal space.

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