Conductivity detector and ion chromatograph

Abstract

The utility model provides a conductivity detector and an ion chromatograph, and the conductivity detector comprises a housing structure which is provided with a containing cavity; the detection structure comprises a detection pool, a preheating group and a heat conduction block, the detection pool is connected with the preheating group, and the detection pool and the preheating group are arranged in an inner cavity of the heat conduction block; the heating structure is arranged in the containing cavity, connected with the heat conduction block and used for heating the heat conduction block and measuring the temperature in the heat conduction block. After being connected into a whole, the detection pool and the preheating group are assembled in the heat conduction block together, the heating structure is connected to the heat conduction block, finally, the detection pool, the heating structure and the heat conduction block are placed in the containing cavity of the shell structure, the heating structure can provide energy needed by heating temperature control, and the preheating group can reduce pressure fluctuation and reduce measurement instability. And the temperature is accurately controlled, and the influence of temperature change on a measurement result is eliminated through temperature compensation.

Description

Technical Field

[0001] This application relates to the technical field of ion chromatography, and more particularly, to a conductivity detector and an ion chromatograph. Background Art

[0002] Ion chromatography is a liquid chromatography method for analyzing anions and cations, and conductivity detection has become the most important detection method in ion chromatography due to its wide linear range, good selectivity, simple structure, and easy automatic operation.

[0003] In related technologies, due to large fluctuations during the measurement process of the conductivity detector, its measurement stability and accuracy are affected. Summary of the Utility Model

[0004] The purpose of this application is to provide a conductivity detector and an ion chromatograph, which can play a buffering role, reduce pressure fluctuations, alleviate measurement instability, and eliminate the influence of temperature changes on measurement results through temperature compensation.

[0005] In a first aspect, an embodiment of this application provides a conductivity detector, including: a housing structure configured with an accommodation cavity; a detection structure disposed in the accommodation cavity, and the detection structure includes a detection cell, a preheating group, and a heat conduction block, the detection cell is connected to the preheating group, and the detection cell and the preheating group are disposed in the inner cavity of the heat conduction block; a heating structure disposed in the accommodation cavity, and the heating structure is connected to the heat conduction block for heating the heat conduction block and measuring the temperature inside the heat conduction block.

[0006] In the above implementation process, after the detection cell and the preheating group are connected as a whole, they are assembled together inside the heat conduction block, and the heating structure is connected to the heat conduction block. Finally, the four are placed in the accommodation cavity of the housing structure. The heating structure can provide the energy required for heating and temperature control. The preheating group can reduce pressure fluctuations, alleviate measurement instability, accurately control the temperature, and eliminate the influence of temperature changes on measurement results through temperature compensation.

[0007] In some embodiments, the detection structure further includes a filler disposed in the inner cavity of the heat conduction block.

[0008] In the above implementation process, after the preheating group and the detection cell are connected, they are placed together inside the heat conduction block, and then filled with the filler to remove the gaps inside the heat conduction block. The filler has high fluidity and becomes a high-strength solid after potting. It can not only conduct energy to make the temperature conduction faster, but also fix the detection cell and the preheating group.

[0009] In some embodiments, the preheating group includes a preheating bracket and a preheating tube. The preheating tube is coiled around the preheating bracket, and the preheating tube is connected to the detection cell.

[0010] In the above implementation process, by coiling, the length of the preheating tube can be increased, which can buffer the pressure, reduce the pressure fluctuation, and increase the preheating area. Moreover, the preheating bracket can also fix the preheating tube to prevent it from moving. When the filler fills all the gaps, the preheating tube can contact the filler, increasing the heat conduction ability and making the heating uniform.

[0011] In some embodiments, the heating structure includes a heating resistor, a thermistor, a circuit board, and a temperature control switch. The heating resistor, the thermistor, and the temperature control switch are connected to the circuit board, and the circuit board is connected to the outside of the heat conducting block.

[0012] In the above implementation process, the heating resistor can be used to provide energy to ensure more uniform supply of the energy required for heating and temperature control. The thermistor, as a temperature probe, can accurately measure the temperature. Under the combined action of the temperature control switch and the thermistor, the start and stop of the heating resistor are controlled to prevent exceeding the high temperature limit.

[0013] In some embodiments, an avoidance hole is arranged on one side of the heat conducting block, the thermistor is arranged in the avoidance hole, and the avoidance hole is filled with a heat conducting material.

[0014] In the above implementation process, the thermistor extends into the interior of the heat conducting block through the avoidance hole, enabling accurate measurement of the temperature inside the heat conducting block, and the heat conducting efficiency can be increased through the heat conducting material.

[0015] In some embodiments, the heating structure further includes a connector. The connector is connected to the circuit board and is exposed on the housing structure. Through this connector, it can be used for subsequent plugging with the main circuit board of the ion chromatograph, which is convenient and fast.

[0016] In some embodiments, the heating structure further includes a heat conducting member. The heat conducting member is connected to the heat conducting block and is attached to the heating resistor. The heat conducting member can play a role in filling and fitting the gaps and increasing the heat conducting efficiency.

[0017] In some embodiments, the housing structure includes an outer shell and a heat preservation component. The heat preservation component is arranged inside the outer shell, and the heat preservation component is configured to accommodate the detection structure and the heating structure.

[0018] In the above implementation process, the detection structure and the heating structure are placed in the heat preservation component, and heat preservation can be carried out through the heat preservation component. The outer shell is used to accommodate the heat preservation component, the detection structure and the heat release structure, and can form a closed shielding layer, which can isolate the electromagnetic field, prevent affecting the ions to be measured, and improve the measurement accuracy.

[0019] In some embodiments, the conductivity detector further includes a two-way joint, which is configured in the housing structure, and the two-way joint is respectively connected to the preheating group and the detection cell.

[0020] In a second aspect, the present application also provides an ion chromatograph, including the conductivity detector as described in any one of the above.

[0021] Since the ion chromatograph provided in the second aspect includes the conductivity detector, the ion chromatograph has all the technical effects of the conductivity detector, which will not be elaborated here.

[0022] Other features and advantages of the present application will be described in the subsequent specification, or some features and advantages can be inferred from the specification or determined without doubt, or can be known by implementing the above technologies of the present application.

[0023] To make the above objects, features and advantages of the present application more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0025] Figure 1 Structural schematic diagram of the conductivity detector provided by the embodiment of the present application;

[0026] Figure 2 Cross-sectional view of the conductivity detector provided by the embodiment of the present application;

[0027] Figure 3 Structural schematic diagram of the preheating group of the conductivity detector provided by the embodiment of the present application;

[0028] Figure 4 Structural schematic diagram of the heating structure of the conductivity detector provided by the embodiment of the present application.

[0029] REFERENCE SIGNS

[0030] 10. Housing structure; 101. Housing component; 102. Panel; 103. First thermal insulation cotton; 104. Second thermal insulation cotton; 20. Detection structure; 201. Detection cell; 202. Preheating bracket; 203. Preheating pipe; 204. Heat conduction block; 205. Filler; 30. Heating structure; 301. Heating resistor; 302. Thermistor; 303. Circuit board; 304. Temperature control switch; 305. Connector; 306. Heat conduction component; 40. Two-way joint. Detailed implementation manner

[0031] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Usually, the components of the embodiments of the present application described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application to be protected, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0032] In the present application, terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0033] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to specific circumstances.

[0034] In addition, terms such as "installation", "setting", "provided with", "connection", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or a point connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is internal communication between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0035] In addition, terms such as "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, the meaning of "a plurality of" is two or more. Embodiment

[0036] Ion chromatography is a type of high-performance liquid chromatography, so it is also called high-performance ion chromatography or modern ion chromatography. The main difference from traditional ion exchange chromatography columns is that the resin has a very high cross-linking degree and a low exchange capacity, the injection volume is very small, and a plunger pump is usually used to transport the eluent, and the eluent is usually subjected to on-line automatic continuous conductivity detection. Separating and determining common anions is the specialty of ion chromatographs. When a sample is injected, the determination results of 7 common ions can be obtained within about 20 minutes, which cannot be achieved by other analytical means. For the determination of cations, ion chromatography does not show superiority compared with AAS and ICP methods.

[0037] Ion chromatography is mainly used for the analysis of environmental samples, including anions and cations in surface water, drinking water, rainwater, domestic sewage and industrial wastewater, acid depositions and atmospheric particulate matter, etc., and the analysis of trace impurities in water and reagents related to the microelectronics industry.

[0038] In this application, the conductivity detector detects and quantifies ions by detecting the change in conductivity in the solution. The specific principle is as follows: The eluent flows through the chromatographic column together with the sample. In the chromatographic column, the analyte (anion or cation) is separated and enters the conductivity cell. At this time, a small voltage is applied to the two electrodes of the conductivity cell. The conductivity measured by the conductivity cell depends on the types and concentrations of ions in the liquid. The ions in the sample will enhance the conductivity of the eluent. Therefore, when the ions in the sample flow through the conductivity cell, the conductivity detected by the conductivity cell will change. The change in conductivity is converted into an electrical signal, amplified, and then sent to the data acquisition system for further processing and analysis. The relationship between the concentration of the analyte ion and the signal response intensity of the detection cell is generally calibrated using a standard solution with a known concentration, so that the signal intensity of the detection cell can be used to quantify the analyte ions in the sample.

[0039] Such as Figures 1-4As shown, in a first aspect, an embodiment of the present application provides a conductivity detector, including: a housing structure 10 configured with an accommodation cavity; a detection structure 20 disposed in the accommodation cavity, and the detection structure 20 includes a detection cell 201, a preheating group, and a heat conduction block 204. The detection cell 201 is connected to the preheating group, and the detection cell 201 and the preheating group are disposed in the inner cavity of the heat conduction block 204; a heating structure 30 disposed in the accommodation cavity, and the heating structure 30 is connected to the heat conduction block 204 to heat the heat conduction block 204 and measure the temperature inside the heat conduction block 204.

[0040] Exemplarily, one end of the preheating tube 203 of the preheating group is connected to the detection cell 201 through a peek joint. After the preheating group and the detection cell 201 are inserted into the heat conduction block 204, the detection cell 201 is fastened from the side of the heat conduction block 204 with a setscrew to prevent the detection cell 201 from rotating during use.

[0041] In the above implementation process, after the detection cell 201 and the preheating group are connected as a whole, they are assembled together inside the heat conduction block 204, and the heating structure 30 is connected to the heat conduction block 204. Finally, the four are placed in the accommodation cavity of the housing structure 10, where the heating structure 30 can provide the energy required for heating and temperature control, the preheating group can reduce pressure fluctuations, reduce measurement instability, accurately control the temperature, and eliminate the influence of temperature changes on the measurement results through temperature compensation.

[0042] As Figure 2 shown, the detection structure 20 further includes a filler 205. The filler 205 includes but is not limited to high thermal conductivity materials. The filler 205 is disposed in the inner cavity of the heat conduction block 204, that is, the filler 205 is poured into the heat conduction block 204 that has been pre-loaded with the preheating group and the detection cell 201, so that it fully fills all the gaps.

[0043] In the above implementation process, after the preheating group and the detection cell 201 are connected, they are placed together inside the heat conduction block 204, and then filled with the filler 205 to remove the gaps inside the heat conduction block 204. The filler 205 has high fluidity and becomes a high-strength solid after potting. It can not only conduct energy to make temperature conduction faster, but also fix the detection cell 201 and the preheating group.

[0044] As Figure 3 shown, the preheating group includes a preheating bracket 202 and a preheating tube 203. The preheating tube 203 is wound around the preheating bracket 202, and the preheating tube 203 is connected to the detection cell 201.

[0045] Exemplarily, the preheating bracket 202 includes, but is not limited to, a semi-circular tube with serrated semi-circular holes machined on its edge. The serrated structure can fix the preheating tube 203 to prevent the preheating tube 203 from moving. The distance between two adjacent semi-circular holes is twice the diameter of the preheating tube 203. Such a specific distance can enable the filler 205 to fully fill all the gaps, so that the tube wall of the preheating tube 203 can contact the filler 205.

[0046] It should be noted that the preheating tube 203 includes, but is not limited to, a high-temperature and high-pressure resistant tube. The preheating tube 203 passes through the hole at one end of the preheating bracket 202, then coils around the semi-circular holes of the preheating bracket 202, and the terminal passes through the hole at the other end of the preheating bracket 202, finally realizing the connection between the preheating tube 203 and the preheating bracket 202.

[0047] In the above implementation process, by means of coiling, the length of the preheating tube 203 can be increased, which can play a role in buffering pressure, reducing pressure fluctuation, and increasing the preheating area. Moreover, the preheating bracket 202 can also fix the preheating tube 203 to prevent the preheating tube 203 from moving. When the filler 205 fills all the gaps, the preheating tube 203 can contact the filler 205, increasing the heat conduction ability and making the heating uniform.

[0048] As Figure 4 shown, the heating structure 30 includes a heating resistor 301, a thermistor 302, a circuit board 303 and a temperature control switch 304. The heating resistor 301, the thermistor 302 and the temperature control switch 304 are connected to the circuit board 303. The circuit board 303 is connected to the outside of the heat conduction block 204. The connection manner of the circuit board 303 to the heat conduction block 204 includes, but is not limited to, screw fixation.

[0049] Exemplarily, the heating structure 30 is located on the outside of the heat conduction block 204. The heating resistor 301 is a heat source. The thermistor 302 includes, but is not limited to, an NTC thermistor 302. The heating resistor 301, the thermistor 302 and the temperature control switch 304 are located on the same side of the circuit board 303. Among them, a plurality of heating resistors 301 are configured. For example, four heating resistors 301 are configured. The plurality of heating resistors 301 are spaced apart on the circuit board 303. The specific distribution position of the heating resistor 301 can be set according to the actual situation, and is used to provide energy together, so as to provide the energy required for heating and temperature control more evenly.

[0050] In the above implementation process, the heating resistor 301 can be used to provide energy to ensure more uniform provision of the energy required for heating and temperature control. The thermistor 302, as a temperature probe, can accurately measure the temperature. Under the combined action of the temperature control switch 304 and the thermistor 302, the start and stop of the heating resistor 301 are controlled to prevent exceeding the high temperature limit.

[0051] In some embodiments, an avoidance hole is configured on one side of the heat conducting block 204, the thermistor 302 is disposed in the avoidance hole, and the avoidance hole is filled with a heat conducting material, which includes but is not limited to heat conducting silica gel. At the same time, after the avoidance hole is filled with the heat conducting material, a layer of colloid can be sealed outside it to prevent the heat conducting silica gel from flowing out and the thermistor 302 from shaking.

[0052] In the above implementation process, the thermistor 302 extends into the interior of the heat conducting block 204 through the avoidance hole, can accurately measure the temperature inside the heat conducting block 204, and can increase the heat conduction efficiency through the heat conducting material.

[0053] Please refer to Figure 4 , the heating structure 30 further includes a connector 305, which includes but is not limited to a DB25 connector. The connector 305 is connected to the circuit board 303, and the connector 305 is exposed on the housing structure 10. Through this connector 305, it can be used for subsequent insertion with the circuit board 303 of the ion chromatograph host, which is convenient and fast.

[0054] In some embodiments, the heating structure 30 further includes a heat conducting member 306, which includes but is not limited to a heat conducting silica film. The heat conducting member 306 is connected to the heat conducting block 204, for example, by a screw fixing method, and is attached to the heating resistor 301. The heat conducting member 306 can play a role in filling and fitting gaps and increasing the heat conduction efficiency.

[0055] As Figures 1-2 shown, the housing structure 10 includes an outer shell and a heat preservation component. The heat preservation component is disposed inside the outer shell, and the heat preservation component is configured to accommodate the detection structure 20 and the heating structure 30.

[0056] Exemplarily, the outer shell includes a housing part 101 and a panel 102. The panel 102 covers the housing part 101, wherein the distribution direction of the housing part 101 includes but is not limited to the front-back direction. The panel 102 is located on the front side of the housing part 101, and both the cover plate and the housing part 101 are made of metal material, and after being assembled together, a closed metal shielding layer is formed.

[0057] The thermal insulation component includes a first thermal insulation cotton 103 and a second thermal insulation cotton 104. The first thermal insulation cotton 103 covers the second thermal insulation cotton 104, and the first thermal insulation cotton 103 is located above the second thermal insulation cotton 104, which can insulate the components inside it and reduce temperature changes.

[0058] In the above implementation process, the detection structure 20 and the heating structure 30 are placed in the thermal insulation component, and can be insulated through the thermal insulation component. The outer shell is used to accommodate the thermal insulation component, the detection structure 20 and the heat release structure, and can form a closed shielding layer, which can isolate the electromagnetic field, prevent affecting the ions to be measured, and improve the measurement accuracy.

[0059] As Figures 1-2 shown, the conductivity detector further includes a two-way joint 40, the two-way joint 40 is arranged on the housing structure 10, and the two-way joint 40 is respectively connected to the preheating group and the detection cell 201.

[0060] Exemplarily, there are two two-way joints 40, and both of the two two-way joints 40 can be fastened to the outer panel 102 with set screws, which can prevent the two-way joint 40 from rotating during use.

[0061] In a second aspect, the present application further provides an ion chromatograph, including the conductivity detector as described above.

[0062] Among them, the working process of the ion chromatograph is as follows: the infusion pump transports the mobile phase to the analysis system at a stable flow rate (or pressure), the sample is introduced through the injector before the chromatographic column, the mobile phase brings the sample into the chromatographic column, each component is separated in the chromatographic column, and then flows to the conductivity detector in sequence with the mobile phase. For suppressed ion chromatography, an additional suppression system is added before the conductivity detector, that is, another high-pressure infusion pump transports the regeneration liquid to the suppressor. In the suppressor, the background conductivity of the mobile phase is reduced, and then the effluent is introduced into the conductivity detector, and the detected signal is sent to the data system for recording, processing or storage.

[0063] Since the ion chromatograph provided in the second aspect includes the conductivity detector, the ion chromatograph has all the technical effects of the conductivity detector, which will not be elaborated here.

[0064] In all embodiments of the present application, "big", "small" are relative, "many", "few" are relative, "up", "down" are relative. For the expression methods of such relative terms, the embodiments of the present application will not elaborate further.

[0065] It should be understood that the "in this embodiment", "in the embodiments of the present application", or "as an alternative embodiment" mentioned throughout the specification means that the specific features, structures, or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the "in this embodiment", "in the embodiments of the present application", or "as an alternative embodiment" that appear throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner. Those skilled in the art should also be aware that the embodiments described in the specification are all alternative embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0066] In various embodiments of the present application, it should be understood that the magnitude of the sequence numbers of the above processes does not necessarily mean the inevitable sequence of execution. The execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0067] As described above, the above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A conductivity detector, characterized in that, Comprising: A housing structure configured with a receiving cavity; A detection structure disposed in the receiving cavity, and the detection structure includes a detection cell, a preheating group, and a heat conducting block. The detection cell is connected to the preheating group, and the detection cell and the preheating group are disposed in the inner cavity of the heat conducting block; A heating structure disposed in the receiving cavity, and the heating structure is connected to the heat conducting block for heating the heat conducting block and measuring the temperature inside the heat conducting block.

2. The conductivity detector according to claim 1, characterized in that, The detection structure further includes a filler disposed in the inner cavity of the heat conducting block.

3. The conductivity detector according to claim 2, characterized in that, The preheating group includes a preheating bracket and a preheating tube. The preheating tube is wound around the preheating bracket, and the preheating tube is connected to the detection cell.

4. The conductivity detector according to claim 1, characterized in that, The heating structure includes a heating resistor, a thermistor, a circuit board, and a temperature control switch. The heating resistor, the thermistor, and the temperature control switch are connected to the circuit board, and the circuit board is connected to the outside of the heat conducting block.

5. The conductivity detector according to claim 4, characterized in that, One side of the heat conducting block is configured with an avoidance hole. The thermistor is disposed in the avoidance hole, and the avoidance hole is filled with a heat conducting material.

6. The conductivity detector according to claim 4 or 5, characterized in that, The heating structure further includes a connector connected to the circuit board and exposed outside the housing structure.

7. The conductivity detector according to claim 6, wherein The heating structure further includes a heat conducting member connected to the heat conducting block and attached to the heating resistor.

8. The conductivity detector according to claim 1, wherein The housing structure includes an outer shell and a heat insulation component. The heat insulation component is disposed inside the outer shell and is configured to accommodate the detection structure and the heating structure.

9. The conductivity detector according to claim 1 or 8, characterized in that, The conductivity detector further includes a two-way joint disposed on the housing structure and respectively connected to the preheating group and the detection cell.

10. An ion chromatograph, characterized in that, Including the conductivity detector according to any one of claims 1-9.

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