High performance liquid chromatograph analyzer uses sample injection device with heating and temperature maintaining function

Abstract

The sample introduction device with heating and insulation functions used in high-performance liquid chromatography (HPLC) analyzers belongs to the technical field of auxiliary mechanisms for analytical equipment. It includes a liquid pump, solenoid valve, primary heating tank, final heating tank, housing, base plate, and connecting pipe, as well as a temperature control circuit. The liquid pump, solenoid valve, primary heating tank, final heating tank, housing, connecting pipe, temperature control circuit, and base plate are installed together. The primary and final heating tanks have identical structures, both including an electric heating element, an inner cylinder, and an outer cylinder. This new device, through the operation of a power switch, allows different types of mobile phases to be pressurized by the liquid pump and enter the inlet pipe of the chromatography column container. Before the next batch of samples is analyzed, the pipes upstream of the inlet pipe of the chromatography column container can be cleaned, providing convenience to staff and improving work efficiency. The two-stage heating and temperature control of the mobile phase through the primary and final heating tanks effectively improves the heating and insulation effect, resulting in more accurate detection data.

Description

Technical Field

[0001] This utility model relates to the field of auxiliary equipment technology for liquid chromatography analyzers, and in particular to an injection device with heating and heat preservation function used in high performance liquid chromatography analyzers. Background Technology

[0002] High-performance liquid chromatography (HPLC) is a device that uses gas chromatography theory to detect and analyze substances, building upon the foundation of classical chromatographic analyzers. Technically, HPLC offers higher detection sensitivity than conventional chromatographic analyzers, allowing for continuous detection of effluents. Specifically, during operation, the HPLC system's injection device uses a liquid pump to draw solvent (the mobile phase) from the reservoir and deliver it to the column container. The analyte (pre-pressed into a column by mixing the analyte with packing material and a small amount of liquid isopropanol) is pre-installed within the column container. The mobile phase (a substance that carries the analyte forward during column detection, such as liquid acetonitrile-water solution, acetonitrile-acetic acid solution, methanol-water solution, acetonitrile-phosphoric acid solution, etc.) is injected through the inlet tube at the top of the column container. The analyte is separated by the chromatographic column located inside the chromatography column container. After separation, the analyte flows out through the lower outlet tube of the chromatography column container and into the detector of the high-performance liquid chromatograph (HPLC). The signal detected by the detector is acquired and processed by the data processing equipment of the HPLC, and the chromatogram of the analyte is recorded, thereby determining the composition of the analyte. After detection, the waste solvent flows out through the lower outlet tube of the detector into an external solvent recovery tank, where it is reused (the separated waste solvent can be reused after further processing).

[0003] In existing high-performance liquid chromatography (HPLC) analyzers, the liquid pump in the inlet device draws the mobile phase from the reservoir and outputs it to the column container. During operation, temperature variations affect the viscosity of the mobile phase: higher temperatures result in lower viscosity and higher flow rates, while lower temperatures lead to higher viscosity and lower flow rates. This directly impacts the retention time of the sample on the column, thus affecting the analytical results. Furthermore, abnormal temperatures can alter the solubility of air bubbles in the mobile phase. High bubble content affects the flow rate of the liquid pump and the sample separation efficiency within the column, also impacting the analytical results. For these reasons, current HPLC analyzers typically install electric heating mechanisms on the outside of the liquid pump inlet or outlet. However, due to the relatively high flow rate of the mobile phase, simply installing electric heating mechanisms at the inlet or outlet cannot effectively guarantee a constant, high temperature for the mobile phase, thus presenting some drawbacks in its application. Furthermore, before analyzing different samples, current sample introduction equipment requires staff to clean the inlet pipes and other pipes of the chromatography column container one by one to prevent residual flow from the previous batch of testing processes and related pipelines from affecting the next batch of testing processes with different types of mobile phases. Since the cleaning workload is large (including cleaning the liquid pump and related pipelines), manual cleaning will cause inconvenience to the staff and will have a certain adverse effect on the detection efficiency. Utility Model Content

[0004] To overcome the drawbacks of existing high-performance liquid chromatography (HPLC) analyzers, such as the inability of the injection equipment to maintain a constant high temperature due to structural limitations, which negatively impacts detection data, and the need for manual cleaning of the inlet tubing and other components of the chromatography column container, which is inconvenient for operators and affects detection efficiency, this invention provides an injection device with heating and insulation functions for HPLC analyzers. This device allows operators to easily operate a power switch to pressurize different mobile phases into the inlet tubing of the chromatography column container via a liquid pump. It also enables convenient and automatic cleaning of the inlet tubing and other components, improving work efficiency. Furthermore, a two-electrode electric heating mechanism heats and maintains the temperature of the mobile phase, enhancing heating and insulation effects and resulting in more accurate detection data.

[0005] The technical solution adopted by this utility model to solve its technical problem is: The high-performance liquid chromatography (HPLC) analyzer uses a sample injection device with heating and insulation functions, including a liquid pump, solenoid valves, a primary heating tank, a final heating tank, a housing, a base plate, and a connecting pipe, as well as a temperature control circuit. Multiple support frames are fixedly installed on the lower outer end of the housing, with their lower ends fixedly installed on one side of the upper end of the base plate. The housing has multiple liquid storage tanks, each with a liquid inlet pipe fixedly installed at its upper end, and a sealing cap installed at the upper end of the inlet pipe. Different types of mobile phase are added to each liquid storage tank. Each housing has an outlet pipe fixedly installed on its lower outer end. Multiple solenoid valves are present, with the lower ends of the outlet pipes fixedly connected to one end of each of the solenoid valves. Multiple branch pipes are fixedly installed on the upper end of the connecting pipe, with the other ends of the solenoid valves, one end of a fifth solenoid valve, the upper ends of the branch pipes, and one end of the connecting pipe fixedly connected. The other end of the fifth solenoid valve is fixedly connected to the inlet pipe of the wastewater tank. The liquid pump is fixedly installed on the other side of the upper end of the base plate. The primary heating tank and the final heating tank have the same structure, each including an electric heating tube, an inner cylinder, and an outer cylinder. Liquid tubes are fixedly installed on both sides of the inner cylinder. The inner side of the electric heating tube is fixedly installed on the outer side of the inner cylinder, and the inner side of the outer cylinder is fixedly installed on the outer side of the electric heating tube. One end of the liquid tube and the other end of the connecting pipe of the primary heating tank are fixedly installed together, and the other end of the liquid tube is fixedly connected to the inlet end of the liquid pump. The lower end of the liquid tube of the final heating tank is fixedly connected to the outlet end of the liquid pump, and the upper end of the liquid tube is fixedly connected to one end of the sixth solenoid valve and one end of the seventh solenoid valve, respectively. The other end of the sixth solenoid valve is fixedly connected to the tap water pipe, and the other end of the seventh solenoid valve is fixedly connected to the inlet pipe of the chromatography column container. The temperature control circuit is installed in the electrical control box, and the power output terminal of the temperature control circuit is electrically connected to the electric heating tubes of the primary heating tank and the final heating tank.

[0006] Furthermore, the multiple solenoid valves are normally closed solenoid valves.

[0007] Furthermore, thermal insulation material is fixedly installed on the outer side of the outer cylinder.

[0008] Furthermore, a vent pipe is fixedly installed on one side of the sealing cover, a filter shell is fixedly installed on the side end of the vent pipe, a filter element is installed inside the filter shell, and there is an air inlet in the middle of the side end of the filter shell.

[0009] Furthermore, the temperature control circuit includes a relay and a temperature switch connected by wires, with the positive power input terminal of the relay connected to one end of the temperature switch, and the negative power input terminal of the relay connected to the positive power output terminal of the power module.

[0010] Furthermore, the temperature switch is fixedly installed on the outside of the liquid pipe at the upper end of the final stage heating tank.

[0011] Compared with the prior art, the advantages of this utility model are: (1) With the simple operation of the power switch, the staff can make different types of mobile phases pressurized by the liquid pump enter the inlet pipe of the chromatography column container. Before the next batch of samples is tested, the pipelines in front of the inlet pipe of the chromatography column container can be automatically cleaned, which brings convenience to the staff and improves the work efficiency accordingly; (2) The mobile phase is heated and kept at a constant temperature by the primary heating tank and the final heating tank, which effectively improves the heating and heat preservation effect and prevents the disadvantage of using only one heating mechanism and not being able to effectively ensure that the mobile phase is at a constant high temperature. Accordingly, the detection data is more accurate. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a schematic diagram of the overall planar structure of this utility model.

[0014] Figure 2 This is a partial three-dimensional structural schematic diagram of the present invention.

[0015] Figure 3 This is the circuit diagram of this utility model. Detailed Implementation

[0016] Figure 1 , 2As shown in Figure 3, the high-performance liquid chromatography (HPLC) analyzer uses a sample injection device with heating and insulation functions, including a liquid pump M (connected in series with a power switch S8 and a 220V AC power supply via a wire), a power switch, a solenoid valve, a primary heating tank, a final heating tank, a power module A1, a housing 3, a base plate 2, a connecting pipe 4, and a temperature control circuit 5. Four support frames 31 are fixedly installed on the lower outer end of the housing 3, and the lower ends of the four support frames are respectively fixedly installed on the upper left side of the base plate 2. The interior of the housing 2 has three partition plates (not shown in the figure) dividing the housing into four sealed and isolated independent liquid storage tanks 32. A liquid addition pipe 321 with external threads at the upper center of each liquid storage tank 32 is fixedly installed. The upper end of the liquid addition pipe 321 is connected to... A sealing cap 322 is fixedly installed with threads. Each storage tank 32 contains different types of mobile phases (such as liquid acetonitrile-aqueous solution, acetonitrile-acetic acid aqueous solution, methanol-aqueous solution, acetonitrile-phosphoric acid aqueous solution, etc.). A liquid outlet pipe 33, communicating with the interior, is fixedly installed in the lower middle part of the outer side of each tank 3. There are seven solenoid valves. The lower ends of four outlet pipes 33 are respectively fixedly connected to one end of four solenoid valves DC1, DC2, DC3, and DC4 via threads. Four branch pipes 41, communicating with the interior, are fixedly installed on the upper end of the connecting pipe 4. The other ends of four solenoid valves DC1, DC2, DC3, and DC4, one end of the fifth solenoid valve DC5, the upper ends of the four branch pipes 41, and the left end of the connecting pipe 4 are respectively... The other end of the fifth solenoid valve DC5 is fixedly connected to the inlet pipe of the waste liquid tank (not shown in the figure) via a pipe. The liquid pump M is fixedly installed on the upper middle part of the right side of the base plate 2. The primary heating tank 1 and the final heating tank have the same structure, both including a spiral electric heating tube RT, an inner cylinder 101, and an outer cylinder 102. A liquid pipe 103 is fixedly installed on the middle part of each side of the inner cylinder 101. The inner side of the electric heating tube RT is tightly fitted to the outer side of the inner cylinder 101 (the two wires connected to the electric heating tube RT are respectively fitted inside the ceramic insulating tube and led out from the openings on the left side of the inner cylinder 101 and the outer cylinder 102, and the openings are sealed with heat-resistant sealant). The inner side of the outer cylinder 101 is tightly fitted to the outer side of the electric heating tube RT. The left and right ends of the outer cylinder 102 are also fixedly fitted to the outer side of the electric heating tube RT. The left and right ends of the liquid pipe 103 are sealed and fixed together; the left end of the liquid pipe 103 of the primary heating tank and the right end of the connecting pipe 4 are fixed together by threads, and the right end of the liquid pipe 103 is fixedly connected to the inlet end of the liquid pump M by a pipe; the lower end of the liquid pipe 103 of the final heating tank and the outlet end of the liquid pump M are fixedly connected by a pipe, the upper end of the liquid pipe 103 and the first end of a three-way pipe are fixedly connected by threads, the second end and the third end of the three-way pipe are fixedly connected to one end of the sixth solenoid valve DC6 and one end of the seventh solenoid valve DC7, respectively, the other end of the sixth solenoid valve DC6 is fixedly connected to the tap water pipe by a pipe, and the other end of the seventh solenoid valve DC7 is fixedly connected to the inlet pipe of the chromatography column container (not shown in the figure) by a pipe.The power module A1, power switches S1, S2, S3, S4, S5, S6, S7, and S8, and temperature control circuit 5 are installed on the circuit board inside the control box 6. The control box 6 is fixedly installed on the upper front middle part of the base plate 2.

[0017] Figure 1 , 2 As shown in Figure 3, the seven solenoid valves are normally closed solenoid valves. Rock wool insulation material (for insulation) is fixedly installed on the outer side of the outer cylinder 102. A vent pipe 3221, communicating with the interior, is fixedly installed at the upper left side of the sealing cover 322. A filter shell 323 is fixedly installed at the left end of the vent pipe 3221. A cotton filter element 34 is installed inside the filter shell 323. An air inlet is located at the middle of the left side of the filter shell 323 (communicating with the inside of the liquid storage tank to prevent a vacuum from forming inside the liquid storage tank). The temperature control circuit 5 includes a relay K and a temperature switch D connected by wires. One end of the temperature switch D is connected to the positive power output pin 3 of the power module A1, and the other end of the temperature switch D is connected to the positive power input pin of the relay K. The negative power input pin of the relay K is connected to the negative power output pin 4 of the power module A1. The temperature switch D is fixedly installed on the outer front side of the liquid pipe 103 at the top of the final stage electric heating tank, with the heated surface of the temperature switch D in close contact with the outer side of the liquid pipe 103. The power input pins 1 and 2 of the power module A1, the control power input pin of the relay K in the temperature control circuit, and the two poles of the 220V AC power supply are connected by wires. The two normally open contacts of the relay K in the temperature control circuit are connected in parallel with the power input pins of the electric heating tubes RT of the primary heating tank and the final stage heating tank, respectively, by wires. The positive power output pin 3 of power module A1 is connected to one power supply terminal of the seven power switches S1, S2, S3, S4, S5, S6, and S7, and one end of the temperature switch D in the temperature control circuit via wires. The other end of the seven power switches S1, S2, S3, S4, S5, S6, and S7, the negative power output pin 4 of power module A1, and the power input terminals of the seven solenoid valves DC1, DC2, DC3, DC4, DC5, DC6, and DC7 are respectively connected via wires. The handles of power switches S1-S8 are located outside the opening at the front of the electrical control box.

[0018] Figure 1 , 2As shown in Figure 3, after the 220V AC power enters the power input terminal of the power module A1, the power module A1 outputs a stable 12V DC power from pins 3 and 4, which enters the power input terminals of power switches S1-S8 and the temperature control circuit. During testing (with the main power switch on), the operator turns on the power switch S8 of the liquid pump M, and then turns on the power switches S1 or S2, S3, S4 and S7 of solenoid valves DC1 or DC2, DC3, DC4 and DC7. As a result, the valve cores of solenoid valves DC1 or DC2, DC3, DC4 and DC7 are energized and open, and the mobile phase in the corresponding first or second, third and fourth liquid storage tanks 32 will enter the inlet terminal of the liquid pump M (after the power switches S1 or S2, S3, S4 and S7 are turned off, the valve cores of solenoid valves DC1 or DC2, DC3, DC4 and DC7 are de-energized and close). After the liquid pump M is powered on, it pressurizes and pumps the input mobile phase out of the chromatography column container. The analyte (the analyte, packing material, and a small amount of liquid isopropanol are mixed and pre-pressed into a chromatography column) is pre-installed in the chromatography column container of the high-performance liquid chromatograph (HPLC). The mobile phase (a substance that carries the analyte forward during the chromatography column detection process, such as liquid acetonitrile-aqueous solution, acetonitrile-acetic acid solution, methanol-aqueous solution, acetonitrile-phosphoric acid solution, etc.) is injected through the inlet tube at the top of the chromatography column container and passes through the chromatography column (chromatographic column) located inside the chromatography column container. After the analyte is separated by the chromatography column, it flows out through the outlet tube at the bottom of the chromatography column container and enters the detector of the HPLC. The signal detected by the detector is acquired and processed by the data processing equipment of the HPLC, and the chromatogram of the analyte is recorded, thereby determining the composition of the analyte. After detection, the waste solvent flows out through the outlet tube at the bottom of the detector into an external solvent recovery tank, and the subsequent solvent is used for other purposes (the separated waste solvent can be reused after processing in other processes). Specifically, in the primary and final heating tanks, when the temperature of the mobile phase output from the liquid pump M is below a certain level (e.g., below 40°C), the internal contacts of the temperature switch D close. This energizes the relay K, closing its control power input terminal and normally open contact. The electric heating element RT in the primary and final heating tanks is then energized to heat the mobile phase flowing through the inner cylinder 101 of the primary and final heating tanks. Conversely, when the temperature of the mobile phase output from the liquid pump M is above a certain level (e.g., above 40°C), the internal contacts of the temperature switch D open. This prevents the relay K from energizing, thus keeping its control power input terminal and normally open contact open. The electric heating element RT in the primary and final heating tanks is no longer energized and does not heat the mobile phase flowing through the inner cylinder 101 of the primary and final heating tanks. Through these methods, the temperature of the mobile phase input into the chromatography column container can be maintained at approximately 40°C.

[0019] Figure 1 , 2As shown in Figure 3, when a different mobile phase is required for the next batch of samples, the operator turns off power switches S1, S2, S3, S4, and S7. This de-energizes solenoid valves DC1, DC2, DC3, DC4, and DC7, causing their cores to close. Then, power switches S5 and S6 are turned on, energizing solenoid valves DC5 and DC6, which open their cores. Pressurized clean water from the tap flows through the opened solenoid valve DC6, through the inlet, volute, outlet of the liquid pump M, and connecting pipe 4, and then through the opened solenoid valve DC5 into the wastewater tank. After sufficient cleaning time, power switches S5 and S6 are turned off, closing the cores of solenoid valves DC5 and DC6. This process is identical to the previous one, allowing the new system to proceed with the next batch of sample testing.

[0020] Figure 1 , 2 As shown in Figure 3, through all the above technical solutions, the operator of this new type of mobile phase can easily pressurize different types of mobile phases into the inlet pipe of the chromatography column container by operating a power switch. Furthermore, before testing the next batch of samples, the upstream pipes of the chromatography column container can be automatically cleaned, providing convenience to the operator and improving work efficiency. The mobile phase is heated and kept at a constant temperature through both primary and final heating tanks, effectively improving the heating and heat preservation effect and preventing the shortcomings of using only a single heating mechanism, which cannot effectively guarantee that the mobile phase is at a constant high temperature. Consequently, the detection data is more accurate. Figure 3 In the diagram, the liquid pump M is a self-priming water pump with an operating voltage of 220V AC and a power of 180W; the solenoid valves DC1, DC2, DC3, DC4, DC5, DC6, and DC7 are 2W normally closed solenoid valves; the power module A1 is a finished product of an AC 220V to DC 12V switching power supply module; the electric heating element RT is a finished product of a stainless steel armored dry-burning electric heating element with a power of 1.5KW; the relay K is a DC12V relay; and the temperature switch D is a finished product of a normally closed contact temperature control switch (40℃) with a model number KSD9400.

[0021] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A sample injection device with heating and heat preservation function used in a high-performance liquid chromatography analyzer, comprising a liquid pump, a solenoid valve, a primary heating vessel, a final heating vessel, a housing, a base plate, and a connecting pipe, characterized in that, It also features a temperature control circuit; multiple support frames are fixedly installed on the lower outer end of the housing, with the lower ends of each support frame fixedly installed on one side of the upper end of the base plate. The housing has multiple liquid storage tanks, each with a liquid inlet pipe fixedly installed on its upper end, and a sealing cap installed on the upper end of the liquid inlet pipe. Different types of mobile phases are added to each liquid storage tank; each housing has a liquid outlet pipe fixedly installed on its lower outer end, and multiple solenoid valves are present. The lower ends of the multiple liquid outlet pipes are fixedly connected to one end of each of the multiple solenoid valves. Multiple branch pipes are fixedly installed on the upper end of the connecting pipe, with the other ends of the multiple solenoid valves, one end of the fifth solenoid valve, the upper ends of the multiple branch pipes, and one end of the connecting pipe fixedly connected. The other end of the fifth solenoid valve is fixedly connected to the inlet pipe of the wastewater tank; the liquid pump is fixedly installed on the other side of the upper end of the base plate, and includes a primary heating tank and a final stage heating tank. The heating tanks have a consistent structure, each including an electric heating tube, an inner cylinder, and an outer cylinder. Liquid tubes are fixedly installed on both sides of the inner cylinder. The electric heating tube is fixedly installed on the outside of the inner cylinder, and the electric heating tube is fixedly installed on the outside of the inner cylinder. One end of the liquid tube and the other end of the connecting pipe of the primary heating tank are fixedly installed together, and the other end of the liquid tube is fixedly connected to the inlet end of the liquid pump. The lower end of the liquid tube of the final heating tank is fixedly connected to the outlet end of the liquid pump, and the upper end of the liquid tube is fixedly connected to one end of the sixth solenoid valve and one end of the seventh solenoid valve, respectively. The other end of the sixth solenoid valve is fixedly connected to a tap water pipe, and the other end of the seventh solenoid valve is fixedly connected to the inlet pipe of the chromatography column container. The temperature control circuit is installed in the electrical control box, and the power output terminal of the temperature control circuit is electrically connected to the electric heating tubes of the primary heating tank and the final heating tank.

2. The sample injection device with heating and heat preservation function used in the high-performance liquid chromatography analyzer according to claim 1, characterized in that, Many of the solenoid valves are normally closed solenoid valves.

3. The sample injection device with heating and heat preservation function used in the high-performance liquid chromatography analyzer according to claim 1, characterized in that, Thermal insulation material is fixedly installed on the outside of the outer cylinder.

4. The sample injection device with heating and heat preservation function used in the high-performance liquid chromatography analyzer according to claim 1, characterized in that, A vent pipe is fixedly installed on one side of the sealing cover, and a filter shell is fixedly installed on the side end of the vent pipe. A filter element is installed inside the filter shell, and there is an air inlet in the middle of the side end of the filter shell.

5. The sample injection device with heating and heat preservation function used in the high-performance liquid chromatography analyzer according to claim 1, characterized in that, The temperature control circuit includes a relay and a temperature switch connected by wires. The positive power input terminal of the relay is connected to one end of the temperature switch, and the negative power input terminal of the relay is connected to the positive power output terminal of the power module.

6. The sample injection device with heating and heat preservation function used in the high-performance liquid chromatography analyzer according to claim 5, characterized in that, The temperature switch is fixedly installed on the outside of the liquid pipe at the top of the final stage heating tank.

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