A device for realizing parallel analysis of ion chromatography-amperometric detection and ion chromatography-high resolution mass spectrometry
Patent Information
- Application Number
- CN202522412459.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-13
- Publication Date
- 2026-10-30
- Estimated Expiration
- 2035-11-13
AI Technical Summary
然而，串联分析会带来比较大的时间延迟和峰扩散，导致相邻峰难以准确分析；且安培检测后串联除盐器和质谱，安培检测中使用的复合银/氯化银(Ag/AgCl)参比电极耐压较差，容易因压力大而损坏；很多离子交换柱的分析流速较大(大多在0.5～1.0mL/min之间)，不适合全部柱后洗脱液进入质谱分析；安培检测多为不可逆反应，会导致分析物的变化，从而干扰质谱定性
[0015]①、本装置采用PEEK材质的分流装置和连接管路，相较于传统不锈钢材质的分流器，PEEK材质能够耐受离子色谱－安培检测中常用的高浓度氢氧化钠流动相，不会像不锈钢那样被碱液腐蚀生锈，从而保障了分流装置和管路的长期稳定使用，避免因材质腐蚀导致的装置故障或分析结果偏差，延长了装置的使用寿命。
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Figure CN224921793U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of instrumental analysis technology, specifically relating to the technical field of analytical devices that combine ion chromatography with amperometric detection and high-resolution mass spectrometry. Background Technology
[0002] Ion chromatography-amperometric detection can analyze electroactive compounds that undergo oxidation or reduction reactions on the working electrode surface. The chromatographic portion of this system typically uses a high-efficiency anion exchange column, employing a gradient elution with sodium hydroxide or sodium hydroxide / sodium acetate aqueous solution as the mobile phase followed by amperometric detection. Qualitative and quantitative analysis is performed by comparing retention times and peak areas with standards, offering high sensitivity. However, for unknown compounds, qualitative analysis is difficult in the absence of standards. Ion chromatography-high-resolution mass spectrometry (IHS-MS) can provide precise mass-to-charge ratios and fragment composition, thus aiding in the qualitative analysis of unknown compounds.
[0003] To achieve simultaneous amperometric detection and mass spectrometry analysis after ion exchange column separation, the eluent can be analyzed via amperometric detection followed by tandem mass spectrometry. However, tandem analysis introduces significant time delays and peak diffusion, making accurate analysis of adjacent peaks difficult. Furthermore, the composite silver / silver chloride (Ag / AgCl) reference electrode used in amperometric detection has poor pressure resistance and is easily damaged by high pressure. Many ion exchange columns have high analytical flow rates (mostly between 0.5 and 1.0 mL / min), making it unsuitable for all eluent to enter mass spectrometry analysis. Amperometric detection is often an irreversible reaction, leading to changes in the analyte and interfering with qualitative mass spectrometry. Additionally, ion chromatography-amperometric detection typically uses an aqueous sodium hydroxide solution or a mixture of sodium hydroxide and sodium acetate as the mobile phase. Traditional splitters are made of stainless steel, which is intolerant to high concentrations of sodium hydroxide and is easily corroded and rusted. Utility Model Content
[0004] The purpose of this invention is to provide a device for parallel analysis of ion chromatography-amperometric detection and ion chromatography-high-resolution mass spectrometry. This device allows the sample to be analyzed to first pass through an ion exchange column for separation, and then the eluent is split through a specific splitting structure. The split eluent is then allowed to enter the amperometric detection unit and the high-resolution mass spectrometry detection unit respectively, and amperometric detection and high-resolution mass spectrometry detection are performed simultaneously. Finally, it realizes the parallel analysis function of amperometric detection and mass spectrometry detection in an online state.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] An apparatus for parallel analysis of ion chromatography-amperometric detection and ion chromatography-high-resolution mass spectrometry (IMS / MS) includes an ion chromatograph, a high-resolution mass spectrometer, an auxiliary pump, and a split device. The ion chromatograph includes a quaternary gradient pump, an autosampler, an ion exchange column, an amperometric detector, a desalter, and a conductivity detector. The outlet of the quaternary gradient pump is connected to the inlet of the autosampler, the outlet of the autosampler is connected to the inlet of the ion exchange column, the outlet of the ion exchange column is connected to the inlet of the split device, one outlet of the split device is connected to the inlet of the amperometric detector, the other outlet of the split device is connected to the mobile phase inlet of the desalter, the mobile phase outlet of the desalter is connected to the inlet of the conductivity detector, the outlet of the conductivity detector is connected to the inlet of the high-resolution mass spectrometer, and the outlet of the auxiliary pump is connected to the regeneration solution inlet of the desalter.
[0007] In one possible implementation, the amperometric detector includes a composite Ag / AgCl reference electrode and a gold working electrode.
[0008] In one possible implementation, the ion exchange column is placed inside a column temperature chamber, which is used to control the temperature of the ion exchange column.
[0009] In one possible implementation, the diversion device includes a tee connector and two PEEK pipes. The inlet of the tee connector is the inlet of the diversion device, and the two outlets of the tee connector are respectively connected to the inlets of the two PEEK pipes. One outlet of the PEEK pipe is the outlet of the diversion device connected to the ampere detector, and the other outlet of the PEEK pipe is the outlet of the diversion device connected to the desalination unit.
[0010] In one possible implementation, the desalter has four ports: a mobile phase inlet, a mobile phase outlet, a regenerated liquid inlet, and a regenerated liquid outlet, wherein the regenerated liquid outlet of the desalter is used to connect to waste liquid.
[0011] In one possible implementation, the regenerator is ultrapure water, which can be introduced into the regenerator inlet via the auxiliary pump.
[0012] In one possible implementation, the connecting lines between the quaternary gradient pump and the autosampler, between the autosampler and the ion exchange column, between the ion exchange column and the split device, between the split device and the amperometric detector, between the split device and the desalter, between the desalter and the conductivity detector, between the conductivity detector and the high-resolution mass spectrometer, and between the auxiliary pump and the desalter are all PEEK tubing.
[0013] In one possible implementation, the outlet of the ampere detector is used to connect to waste liquid.
[0014] Compared with the prior art, the advantages of this utility model are as follows:
[0015] ① This device uses a PEEK material for the split device and connecting pipeline. Compared with the traditional stainless steel split device, PEEK material can withstand the high concentration of sodium hydroxide mobile phase commonly used in ion chromatography-amperometric detection. Unlike stainless steel, it will not be corroded and rusted by alkaline solutions, thus ensuring the long-term stable use of the split device and pipeline, avoiding device failure or deviation of analysis results due to material corrosion, and extending the service life of the device.
[0016] ② This device employs a parallel structure of an amperometric detector, a desalting unit, and a mass spectrometer. Compared to traditional tandem analysis methods, the eluent, after splitting, can enter the amperometric detection branch and the mass spectrometry analysis branch separately, eliminating the need for sequential passage through the two detection systems and effectively reducing the time delay issues common in tandem analysis. Simultaneously, the parallel structure avoids peak diffusion during long-distance transport of the eluent, ensuring peak consistency on the amperometric detector and mass spectrometer, facilitating accurate peak identification and improving the accuracy of adjacent peak analysis. Furthermore, in tandem analysis, the desalting unit and mass spectrometer after amperometric detection introduce high pressure, potentially damaging the pressure-sensitive composite Ag / AgCl reference electrode. In contrast, the parallel structure eliminates the additional pressure from the subsequent desalting unit and mass spectrometer, significantly improving the reference electrode's durability, reducing the probability of electrode damage, and minimizing equipment maintenance costs and downtime.
[0017] ③ This device sets the split ratio by adjusting the length and pressure of the PEEK tubing in the split device. It can flexibly control the amount of eluent entering the amperometric detector and mass spectrometer according to the analytical flow rate requirements of different ion exchange columns. This avoids the problem of all the eluent entering the mass spectrometer due to the high analytical flow rate of the ion exchange column. It ensures that the eluent flow rate entering the mass spectrometer matches the optimal flow rate requirement of the ion source of the mass spectrometer, guaranteeing the normal operation and sensitivity of mass spectrometry analysis, improving the adaptability of the device to ion exchange columns with different flow rates, and expanding the applicability of the device.
[0018] ④ This device is equipped with a desalter in the mass spectrometry analysis branch. The eluent after the column passes through the desalter before entering the mass spectrometer. The desalter removes sodium ions (Na+) from the eluent. + ) and hydrogen ions (H + An exchange occurs, thereby removing Na from the eluent. +The remaining aqueous acetic acid solution, due to the volatility of acetic acid, can be directly introduced into the mass spectrometer. This effectively avoids the corrosion of the mass spectrometer ion source nozzle and cone caused by the high concentration of sodium hydroxide and sodium acetate in the original mobile phase, as well as problems such as clogging in the nozzle and salt accumulation in the cone. This ensures the stable performance of the mass spectrometer, guarantees the continuous and reliable operation of mass spectrometry analysis, reduces analytical interruptions caused by damage or contamination of mass spectrometry components, and improves the efficiency and accuracy of mass spectrometry analysis.
[0019] ⑤ Because the ampere detector and mass spectrometer adopt a parallel structure, the eluent entering the mass spectrometer does not pass through the ampere detection stage. The irreversible reaction in the ampere detection only occurs in the eluent of the ampere detection branch, which will not affect the analyte properties in the eluent of the mass spectrometry analysis branch. This avoids the situation where the reaction of the analyte interferes with the qualitative analysis of the mass spectrometer, enabling the mass spectrometer to obtain accurate mass-to-charge ratio and fragment information based on the original properties of the analyte, further improving the accuracy of the qualitative analysis of unknown compounds. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the parallel analysis device in an embodiment of the present invention;
[0022] Figure 2 This is another structural schematic diagram of the parallel analysis device in this utility model embodiment;
[0023] In the diagram, 1 is the quaternary gradient pump, 2 is the autosampler, 3 is the ion exchange column (placed in the column oven), 4 is the T-connector, 5 and 7 are PEEK tubing for splitting, 8 is the desalting device, 9 is the auxiliary pump, 10 is the conductivity detector, and 11 is the high-resolution mass spectrometer; 12 is the outlet of the quaternary gradient pump, 21 is the inlet of the autosampler, 22 is the outlet of the autosampler, 31 is the inlet of the ion exchange column, 32 is the outlet of the ion exchange column, 41 is the inlet of the T-connector, and 42 and 4... 3 are all T-connector outlets; 51 and 71 are both PEEK pipeline inlets of the shunt device; 52 and 72 are both PEEK pipeline outlets of the shunt device; 61 is the ampere detector inlet; 62 is the ampere detector outlet; 81 is the desalter mobile phase inlet; 82 is the desalter mobile phase outlet; 83 is the desalter regenerated liquid inlet; 84 is the desalter regenerated liquid outlet; 1a is the conductivity detector inlet; 1b is the conductivity detector outlet; and 2a is the high-resolution mass spectrometer inlet. Detailed Implementation
[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0025] Example:
[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, in the embodiments of this utility model are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.
[0027] In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0028] Figure 1 This is a schematic diagram of the parallel analysis device in an embodiment of the present invention; Figure 2 This is another structural schematic diagram of the parallel analysis device in this utility model embodiment; see also Figure 1 and Figure 2This utility model provides an apparatus for parallel analysis of ion chromatography-amperometric detection and ion chromatography-high-resolution mass spectrometry, including an ion chromatograph, a high-resolution mass spectrometer, an auxiliary pump, and a split device. The ion chromatograph includes a quaternary gradient pump, an autosampler, an ion exchange column, an amperometric detector, a desalter, and a conductivity detector. The outlet of the quaternary gradient pump is connected to the inlet of the autosampler, the outlet of the autosampler is connected to the inlet of the ion exchange column, the outlet of the ion exchange column is connected to the inlet of the split device, one outlet of the split device is connected to the inlet of the amperometric detector, the other outlet of the split device is connected to the mobile phase inlet of the desalter, the mobile phase outlet of the desalter is connected to the inlet of the conductivity detector, the outlet of the conductivity detector is connected to the inlet of the high-resolution mass spectrometer, and the outlet of the auxiliary pump is connected to the regeneration solution inlet of the desalter.
[0029] In some embodiments, the amperometric detector includes a composite Ag / AgCl reference electrode and a gold working electrode.
[0030] In some embodiments, the ion exchange column is placed inside a column temperature chamber for temperature control of the ion exchange column.
[0031] In some embodiments, the diversion device includes a tee connector and two PEEK pipes. The inlet of the tee connector is the inlet of the diversion device, and the two outlets of the tee connector are respectively connected to the inlets of the two PEEK pipes. One outlet of the PEEK pipe is the outlet of the diversion device connected to the ampere detector, and the other outlet of the PEEK pipe is the outlet of the diversion device connected to the desalination unit.
[0032] In some embodiments, the desalter has four ports: a mobile phase inlet, a mobile phase outlet, a regenerated liquid inlet, and a regenerated liquid outlet, wherein the regenerated liquid outlet of the desalter is used to connect to waste liquid.
[0033] In some embodiments, the regenerator is ultrapure water, which can enter the regenerator inlet via the auxiliary pump.
[0034] In some embodiments, the connecting lines between the quaternary gradient pump and the autosampler, between the autosampler and the ion exchange column, between the ion exchange column and the split device, between the split device and the amperometric detector, between the split device and the desalter, between the desalter and the conductivity detector, between the conductivity detector and the high-resolution mass spectrometer, and between the auxiliary pump and the desalter are all PEEK tubing.
[0035] In some embodiments, the outlet of the ampere detector is used to connect to waste liquid.
[0036] The working principle of this device is described below: When analyzing electroactive compounds such as ions or sugars using the above connection, separation is achieved using the principle of ion exchange. For example, in the analysis of carbohydrates, carbohydrate molecules exist in anionic form under alkaline conditions. Neutral carbohydrates are weak acids with a dissociation constant pKa between 12 and 14. In a mobile phase with a sufficiently high pH, they will exist partially or entirely in anionic form, which can be retained and separated on an anion exchange column. For the separation of monosaccharides, 10–200 mmol / L sodium hydroxide is generally used as the mobile phase. For the separation of oligosaccharides and polysaccharides, an affinity for hydroxide ions (OH-) greater than that for the stationary phase needs to be added to the mobile phase. - The eluting ions are acetate ions, so sodium hydroxide and sodium acetate are commonly used for gradient elution. The retention of oligosaccharides and polysaccharides on anion exchange resins is mainly related to the size and properties of the molecules. Generally, the retention on the column is enhanced with the increase of the degree of polymerization and the number of hydroxyl groups in the molecule.
[0037] Amperometric detection requires alkaline conditions, which is well-suited for high-performance anion exchange (HPLC) and carbohydrate analysis. Amperometric detection uses a gold electrode as the working electrode and a composite Ag / AgCl electrode as the reference electrode. When a potential is applied to the gold electrode, compounds with hydroxyl or amino groups in their molecular structure readily undergo oxidation or reduction reactions on the gold electrode surface.
[0038] The high concentrations of sodium hydroxide and sodium acetate in the mobile phase used in the front-end cannot be directly introduced into organic mass spectrometry analysis. They corrode the nozzle and cone of the mass spectrometry ion source, clog the nozzle, and accumulate salt at the cone, severely affecting the performance of the mass spectrometer and the analytical work. Therefore, desalting is necessary before mass spectrometry analysis. After passing through a desalter, the post-column eluent contains sodium... + In the desalter with H + It was removed through an exchange. Na was removed. + The eluent contains only an aqueous solution of acetic acid and the separated compound. Acetic acid is volatile and can be analyzed by mass spectrometry. The sample is ionized in the mass spectrometer ion source, converting it into charged gas-phase ions. These ions then enter the mass analyzer for mass-to-charge ratio measurement. Under the influence of physical fields such as electric and magnetic fields, the trajectories of the ions differ, and the detector converts these ions into electronic signals, which are then converted into a mass spectrum. Utilizing different functional groups such as hydroxyl and amino groups in the compound structure, mass spectrometry analysis can be performed by setting positive ion, negative ion, and secondary scan modes using high-resolution mass spectrometry, thereby obtaining its precise mass-to-charge ratio and secondary fragment information.
[0039] The following describes the operation of this device: First, equilibrate the ion exchange column and desalinate the system. Step 1: Configure the mobile phase according to the separation requirements, ensuring it is protected by an inert gas to minimize the absorption of carbon dioxide from the air. Step 2: Fill the bottle (4 liters or 2 liters) with ultrapure water for the auxiliary pump 9. Step 3: Following the connection method described above, do not connect the mass spectrometer 11 after the conductivity detector 10. The mobile phase flows from the quaternary gradient pump 1 to the autosampler 2, then to the ion exchange column (temperature controlled in the column oven) 3. Connect the ion exchange column outlet 32 to the inlet 41 of the three-way connector 4 of the split device. Connect one end of the three-way connector 4 (outlet 42) to the inlet 61 of the amperometric detector 6, and connect the outlet 62 to the waste liquid. Connect the other end (outlet 43) to the mobile phase inlet 81 of the desalter. Connect the mobile phase outlet 82 of the desalter to the inlet 1a of the conductivity detector, and the outlet 1b of the conductivity detector to the waste liquid. Connect the outlet 92 of the auxiliary pump 9 to the regeneration inlet 83 of the desalter 8, and connect the regeneration outlet 84 to the waste liquid. All connecting pipes are made of PEEK tubing (polyetheretherketone), and the flow splitter is also made of PEEK. Fourth step: Open the waste valve of the quaternary gradient pump 1 to discharge waste liquid from flow paths A, B, and C at high flow rates, then tighten the waste valve. Fifth step: Place the ion exchange column 3 into the column oven, set the oven temperature as needed, set the flow rate of the quaternary gradient pump 1 according to the proportion of high-concentration salts in the chromatographic separation conditions, turn on the quaternary gradient pump 1 and auxiliary pump 9 at the required flow rates, set the suppression current of the desalter 8, and observe the background conductivity signal through the conductivity detector 10 to determine the desalting effect. Sixth step: Set the parameters of the amperometric detector 6, select the waveform according to the properties of the unknown compound, turn on the amperometric cell voltage, and balance the instrument.
[0040] Before preparing for sample analysis, connect outlet 1b of the conductivity detector to mass spectrometer 11 and start mass spectrometry scanning.
[0041] During sample analysis, the sample is placed in the autosampler 2, and analysis begins. The autosampler 2 injects the sample, which is carried into the system flow path through its six-way valve. The mobile phase carries the sample into the ion exchange column 3 for separation. The post-column eluent is split into two flow paths by the splitter 4. One path passes through the desalted mass spectrometer 11 for analysis, while the other path passes through the amperometric detector 6 for analysis. The split ratio is related to the length and pressure of the PEEK tubing 5 and 7 of the splitter. To achieve a split ratio of 1:1, two 1-meter-long PEEK tubing lines (0.005-inch inner diameter) can be connected to each of the two outlets after the tee. To achieve a split ratio of amperometric detection:mass spectrometry detection = 3:1, the length of the tubing connected to the amperometric detector is one-third the length of the mass spectrometry tubing of the same inner diameter.
[0042] It should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0043] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0045] The above embodiments are merely illustrative of the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made based on the substance of the content of this utility model should be covered within the scope of protection of this utility model.
Claims
1. A device for parallel analysis using ion chromatography-amperometric detection and ion chromatography-high-resolution mass spectrometry, characterized in that, The system includes an ion chromatograph, a high-resolution mass spectrometer, an auxiliary pump, and a split device. The ion chromatograph includes a quaternary gradient pump, an autosampler, an ion exchange column, an amperometric detector, a desalter, and a conductivity detector. The outlet of the quaternary gradient pump is connected to the inlet of the autosampler. The outlet of the autosampler is connected to the inlet of the ion exchange column. The outlet of the ion exchange column is connected to the inlet of the split device. One outlet of the split device is connected to the inlet of the amperometric detector. The other outlet of the split device is connected to the mobile phase inlet of the desalter. The mobile phase outlet of the desalter is connected to the inlet of the conductivity detector. The outlet of the conductivity detector is connected to the inlet of the high-resolution mass spectrometer. The outlet of the auxiliary pump is connected to the regeneration solution inlet of the desalter.
2. The apparatus according to claim 1, characterized in that, The amperometric detector includes a composite Ag / AgCl reference electrode and a gold working electrode.
3. The apparatus according to claim 1, characterized in that, The ion exchange column is placed inside a column temperature chamber, which is used to control the temperature of the ion exchange column.
4. The apparatus according to claim 1, characterized in that, The diversion device includes a three-way connector and two PEEK pipes. The inlet of the three-way connector is the inlet of the diversion device, and the two outlets of the three-way connector are respectively connected to the inlets of the two PEEK pipes. One outlet of the PEEK pipe is the outlet of the diversion device connected to the ampere detector, and the other outlet of the PEEK pipe is the outlet of the diversion device connected to the desalination unit.
5. The apparatus according to claim 1, characterized in that, The desalter has four ports: a mobile phase inlet, a mobile phase outlet, a regenerated liquid inlet, and a regenerated liquid outlet. The regenerated liquid outlet of the desalter is used to connect to the waste liquid.
6. The apparatus according to claim 1, characterized in that, The regenerated solution of the desalter is ultrapure water, which can enter the regenerated solution inlet of the desalter through the auxiliary pump.
7. The apparatus according to claim 1, characterized in that, The connecting lines between the quaternary gradient pump and the autosampler, between the autosampler and the ion exchange column, between the ion exchange column and the split device, between the split device and the amperometric detector, between the split device and the desalter, between the desalter and the conductivity detector, between the conductivity detector and the high-resolution mass spectrometer, and between the auxiliary pump and the desalter are all PEEK tubing.
8. The apparatus according to claim 1, characterized in that, The outlet of the ampere detector is used to connect to the waste liquid.