Liquid-phase ion chromatographic analysis system and method based on ion selective screening technology

Abstract

The invention discloses a liquid-phase ion chromatographic analysis system and method based on an ion selective screening technology. Comprising a discharge pipeline, a sample output pipeline, a fluorine ion selective screening system, a chloride ion selective screening system, a sulfate ion selective screening system, a nitrite ion selective screening system, a nitrate ion selective screening system, an electric automatic regeneration pure water preparation system and a pure water leaching pipeline. Meanwhile, a leaching system containing chemical components and an ion suppressor for reducing the background conductivity of leacheate do not need to be provided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chromatographic analysis, and relates to a liquid phase ion chromatography analysis system and method based on ion selective screening technology. BACKGROUND

[0002] As a kind of high performance liquid chromatography (HPLC), liquid phase ion chromatography analysis technology can accurately measure the content of anions and cations in water samples, has a low detection limit and high accuracy, and is widely used in water quality analysis in scientific research, biology, pharmacy and other fields. Although it has many advantages, it also has some technical defects.

[0003] 1) Although modern ion chromatographs have achieved high automation, the operation of instrument debugging, parameter setting, method establishment, optimization and data analysis still requires the operator to have certain professional knowledge and experience. Due to the complexity of operation and the precision of the system, it is difficult to realize online measurement as a laboratory analysis equipment;

[0004] 2) The separation effect and selectivity of ion chromatography largely depend on the selection of the mobile phase. If the selected mobile phase is not appropriate, it may lead to poor separation effect or inability to separate the sample components, thereby affecting the accuracy of the analysis results;

[0005] 3) Since the sample may contain impurities or strongly adsorbed substances, these substances are easy to accumulate on the chromatographic column and cause column pollution, thereby affecting the service life and separation effect of the chromatographic column.

[0006] 4) The current ion chromatograph separation system is a high-pressure resin separation column, which requires a high-pressure sampling system. Different components have different residence times on the separation column, and the analysis of anion and cation full indicators often takes more than 30 minutes. In order to protect the high-pressure separation system and reduce the background conductivity of the eluent, a protection column, an ion suppressor and other precision accessories are also required. SUMMARY

[0007] The present application aims to overcome the above-mentioned shortcomings of the prior art and provides a liquid phase ion chromatography analysis system and method based on ion selective screening technology, which can realize online measurement without the need to provide an elution system containing chemical components and an ion suppressor to reduce the background conductivity of the eluent.

[0008] To achieve the above-mentioned purpose, the present application discloses a liquid phase ion chromatography analysis system based on ion selective screening technology, which comprises an exhaust pipeline, a sample output pipeline, a fluoride ion selective screening system, a chloride ion selective screening system, a sulfate ion selective screening system, a nitrite ion selective screening system, a nitrate ion selective screening system, an electric automatic regeneration pure water preparation system and a pure water elution pipeline.

[0009] The sample output pipeline is connected with the primary side inlet of the fluoride ion selective separation system, the primary side outlet of the fluoride ion selective separation system is connected with the primary side inlet of the chloride ion selective separation system, the primary side outlet of the chloride ion selective separation system is connected with the primary side inlet of the sulfate ion selective separation system, the primary side outlet of the sulfate ion selective separation system is connected with the primary side inlet of the nitrite ion selective separation system, the primary side outlet of the nitrite ion selective separation system is connected with the primary side inlet of the nitrate ion selective separation system, and the primary side outlet of the nitrate ion selective separation system is connected with the discharge pipeline.

[0010] The secondary side outlet of the fluoride ion selective separation system is connected with the first micro-flow conductivity detection system, the secondary side of the chloride ion selective separation system, the second micro-flow conductivity detection system, the secondary side of the sulfate ion selective separation system, the third micro-flow conductivity detection system, the secondary side of the nitrite ion selective separation system, the fourth micro-flow conductivity detection system, the secondary side of the nitrate ion selective separation system, and the fifth micro-flow conductivity detection system, and the inlet of the pure water preparation system and the pure water elution pipeline of the automatic regeneration system, and the outlet of the pure water elution pipeline is connected with the secondary side inlet of the fluoride ion selective separation system.

[0011] The liquid phase ion chromatography analysis system based on the ion selective separation technology further improves in that:

[0012] Further, the primary side and the secondary side of the fluoride ion selective separation system are separated by a fluoride ion selective separation membrane.

[0013] Further, the primary side and the secondary side of the chloride ion selective separation system are separated by a chloride ion selective separation membrane.

[0014] Further, the primary side and the secondary side of the sulfate ion selective separation system are separated by a sulfate ion selective separation membrane.

[0015] Further, the primary side and the secondary side of the nitrite ion selective separation system are separated by a nitrite ion selective separation membrane.

[0016] Further, the primary side and the secondary side of the nitrate ion selective separation system are separated by a nitrate ion selective separation membrane.

[0017] The application discloses a liquid phase ion chromatography analysis method based on ion selective separation technology.

[0018] The conductivity detected by the first micro-flow conductivity detection system is C1.

[0019] The conductivity detected by the second micro-flow conductivity detection system is C2.

[0020] The conductivity detected by the third microfluidic conductivity detection system is C3;

[0021] The conductivity detected by the fourth microfluidic conductivity detection system is C4;

[0022] The conductivity detected by the fifth microfluidic conductivity detection system is C5;

[0023] The fluoride ion concentration, chloride ion concentration, sulfate ion concentration, nitrite ion concentration, and nitrate ion concentration are calculated based on C1, C2, C3, C4, and C5.

[0024] The further improvement of the liquid ion chromatography analysis method based on ion selective screening technology of the present invention is:

[0025] Furthermore, C1=C 纯水 +c H ·A H +c F ·A F , where c H is the molar concentration of hydrogen ions, A H is the limiting molar conductivity of hydrogen ions, c F is the molar concentration of fluoride ions, A F is the limiting molar conductivity of fluoride ions, c H =c F ;

[0026] C2-C1=c H ·A H +c Cl ·A Cl , where c Cl is the molar concentration of chloride ions, A Cl is the limiting molar conductivity of chloride ions, c H =c CL .

[0027] Furthermore, C3-C2=c H ·A H +c SO4 ·A SO4 , where c SO4 is the molar concentration of sulfate, A SO4 is the limiting molar conductivity of sulfate, c H =2c SO4 ;

[0028] C4-C3=c H ·A H +c NO2 ·A NO2 , where c NO2 is the molar concentration of nitrite, A NO2 is the limiting molar conductivity of nitrite, cH = c NO2 .

[0029] Further, C5-C4=c H ·A H +c NO3 ·A NO3 , wherein c NO3 is the molar concentration of nitrate, A NO3 is the limiting molar conductivity of nitrate, c H = c NO3 .

[0030] The present application has the following beneficial effects:

[0031] The liquid phase ion chromatography analysis system and method based on ion selective screening technology according to the present application, in specific operation, utilizes a fluoride ion selective screening system, a chloride ion selective screening system, a sulfate ion selective screening system, a nitrite ion selective screening system and a nitrate ion selective screening system to screen fluoride ions, chloride ions, sulfate ions, nitrite ions and nitrate ions respectively, and then utilizes a first micro-flow conductivity detection system, a second micro-flow conductivity detection system, a third micro-flow conductivity detection system, a fourth micro-flow conductivity detection system and a fifth micro-flow conductivity detection system to measure the conductivity of water after screening, and to calculate the concentrations of fluoride ions, chloride ions, sulfate ions, nitrite ions and nitrate ions, so that the system structure is simple and the operation is simple, and the system can not only be used as a laboratory analysis system, but also can realize online measurement, and does not need to provide a chemical composition containing elution system and an ion suppressor for reducing the background conductivity of eluent, and the environmental protection and economy of the system are more optimal, and the system overcomes the different disadvantages of different retention times of different components of traditional high-pressure separation resin columns, and ion migration can be completed almost instantaneously, and the measurement efficiency is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0032] The drawings accompanying the specification of the present application serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0033] Figure 1 is a structural diagram of the present application.

[0034] In the drawings, 1 is a fluoride ion selective screening system, 2 is a chloride ion selective screening system, 3 is a sulfate ion selective screening system, 4 is a nitrite ion selective screening system, 5 is a nitrate ion selective screening system, 6 is a first micro-flow conductivity detection system, 7 is a second micro-flow conductivity detection system, 8 is a third micro-flow conductivity detection system, 9 is a fourth micro-flow conductivity detection system, and 10 is a fifth micro-flow conductivity detection system. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the terms "comprising" and "including" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or sets thereof.

[0037] It should also be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0038] It should be further understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations thereof, and includes these combinations, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0039] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present application to describe the preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, the first preset range can also be referred to as the second preset range, and similarly, the second preset range can also be referred to as the first preset range without departing from the scope of the embodiments of the present application.

[0040] Depending on the context, the word "if" as used herein can be interpreted to mean "when" or "while" or "in response to determining" or "in response to detecting". Similarly, the phrase "if determined" or "if detecting (a stated condition or event)" can be interpreted to mean "when determined" or "in response to determining" or "when detecting (a stated condition or event)" or "in response to detecting (a stated condition or event)", depending on the context.

[0041] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0042] Various structural schematic diagrams according to the disclosed embodiments of the present application are shown in the drawings. These diagrams are not drawn to scale, in which some details are exaggerated for the purpose of clear expression, and some details can be omitted. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are only exemplary, and in actuality, there can be deviations due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes and relative positions can be additionally designed by those skilled in the art according to actual needs.

[0043] With reference to Figure 1 The liquid-phase ion chromatography analysis system based on ion-selective screening technology according to the present application includes a fluoride ion-selective screening system 1, a chloride ion-selective screening system 2, a sulfate ion-selective screening system 3, a nitrite ion-selective screening system 4, a nitrate ion-selective screening system 5, a first micro-flow conductivity detection system 6, a second micro-flow conductivity detection system 7, a third micro-flow conductivity detection system 8, a fourth micro-flow conductivity detection system 9 and a fifth micro-flow conductivity detection system 10.

[0044] The sample output pipeline is connected in communication with the primary side inlet of the fluoride ion-selective screening system 1, the primary side outlet of the fluoride ion-selective screening system 1 is connected in communication with the primary side inlet of the chloride ion-selective screening system 2, the primary side outlet of the chloride ion-selective screening system 2 is connected in communication with the primary side inlet of the sulfate ion-selective screening system 3, the primary side outlet of the sulfate ion-selective screening system 3 is connected in communication with the primary side inlet of the nitrite ion-selective screening system 4, the primary side outlet of the nitrite ion-selective screening system 4 is connected in communication with the primary side inlet of the nitrate ion-selective screening system 5, and the primary side outlet of the nitrate ion-selective screening system 5 is connected in communication with the discharge pipeline.

[0045] The secondary side outlet of the fluorine ion selective screening system 1 is connected with the inlet of the electric automatic regeneration pure water preparation system and the pure water elution pipeline through the first micro-flow conductivity detection system 6, the secondary side of the chlorine ion selective screening system 2, the second micro-flow conductivity detection system 7, the secondary side of the sulfate ion selective screening system 3, the third micro-flow conductivity detection system 8, the secondary side of the nitrite ion selective screening system 4, the fourth micro-flow conductivity detection system 9, the secondary side of the nitrate ion selective screening system 5 and the fifth micro-flow conductivity detection system 10, and the outlet of the pure water elution pipeline is connected with the secondary side inlet of the fluorine ion selective screening system 1.

[0046] The primary side and the secondary side of the fluorine ion selective screening system 1 are divided by a fluorine ion selective screening membrane;

[0047] The primary side and the secondary side of the chlorine ion selective screening system 2 are divided by a chlorine ion selective screening membrane;

[0048] The primary side and the secondary side of the sulfate ion selective screening system 3 are divided by a sulfate ion selective screening membrane;

[0049] The primary side and the secondary side of the nitrite ion selective screening system 4 are divided by a nitrite ion selective screening membrane;

[0050] The primary side and the secondary side of the nitrate ion selective screening system 5 are divided by a nitrate ion selective screening membrane;

[0051] The liquid phase ion chromatography analysis method based on the ion selective screening technology comprises the following steps:

[0052] 1) The sample to be detected flows through the primary side of the fluorine ion selective screening system 1, the primary side of the chlorine ion selective screening system 2, the primary side of the sulfate ion selective screening system 3, the primary side of the nitrite ion selective screening system 4 and the primary side of the nitrate ion selective screening system 5 in sequence and is finally discharged;

[0053] 2) The middle part of the fluorine ion selective screening system 1 is a fluorine ion selective screening membrane, based on the design of the functional group and the channel aperture, the membrane structure only allows fluorine ions to pass through, and the fluorine ions in the primary side of the fluorine ion selective screening system 1 migrate to the secondary side of the fluorine ion selective screening system 1 along the direction of the blue arrow;

[0054] 3) Similarly, the chlorine ions, sulfate ions, nitrite ions and nitrate ions in the water sample migrate to the secondary side of the system along the direction of the blue arrow of the selective screening membrane in the middle part of 2-5;

[0055] 4) The eluent of the chromatographic analysis system uses online real-time prepared pure water (conductivity 0.055 μS / cm, resistivity 18.25 MΩ), compared with the traditional ion chromatographic analysis system eluent using chemical reagents, the system is more environmentally friendly and economical;

[0056] 5) The pure water eluent sequentially passes through the secondary side of the fluoride ion selective screening system 1, the first micro-flow conductivity detection system 6, the secondary side of the chloride ion selective screening system 2, the second micro-flow conductivity detection system 7, the secondary side of the sulfate ion selective screening system 3, the third micro-flow conductivity detection system 8, the secondary side of the nitrite ion selective screening system 4, the fourth micro-flow conductivity detection system 9, the secondary side of the nitrate ion selective screening system 5, and the fifth micro-flow conductivity detection system 10, and finally enters the electrically automatic regenerating pure water preparation system;

[0057] 6) The electrically automatic regenerating pure water preparation system removes the carried ions and further prepares high-purity water for recycling;

[0058] 7) The pure water eluent carries the migrated fluoride ions after passing through the secondary side of the fluoride ion selective screening system 1, forming a certain concentration of HF (hydrofluoric acid) solution, and the first micro-flow conductivity detection system 6 detects its conductivity C1;

[0059] 8) Further, after passing through the secondary side of the chloride ion selective screening system 2, the carried chloride ions migrate, forming an HCl (hydrochloric acid) and HF (hydrofluoric acid) mixed solution, and the second micro-flow conductivity detection system 7 detects its conductivity C2, and the contribution of HCl to the conductivity is C2-C1;

[0060] 9) Similarly, the detection results of the third micro-flow conductivity detection system 8, the fourth micro-flow conductivity detection system 9, and the fifth micro-flow conductivity detection system 10 are C3, C4, and C5, respectively, and the contribution of H2SO4 reflecting the sulfate content to the conductivity is C3-C2, the contribution of HNO2 reflecting the nitrite content to the conductivity is C4-C3, and the contribution of HNO3 reflecting the nitrate content to the conductivity is C5-C4;

[0061] 10) C1 (μS / cm) = C 纯水 + c H · A H + c F · A F

[0062] Wherein, c H is the molar concentration of hydrogen ions (mmol / L), A H is the limiting molar conductivity of hydrogen ions (349.9 S·cm 2 / mol), and c Fis the molar concentration of fluoride ions (mmol / L), A F is the limiting molar conductivity of fluoride ions (55.4 S-cm 2 / mol), c H = c F .

[0063] 11) C2 - C1 = c H · A H + c Cl · A Cl

[0064] where c Cl is the molar concentration of chloride ions (mmol / L), A Cl is the limiting molar conductivity of chloride ions (76.3 S-cm 2 / mol), c H = c CL .

[0065] 12) C3 - C2 = c H · A H + c SO4 · A SO4

[0066] where c SO4 is the molar concentration of sulfate ions (mmol / L), A SO4 is the limiting molar conductivity of sulfate ions (82.0 S-cm 2 / mol), c H = 2c SO4 .

[0067] 13) C4 - C3 = c H · A H + c NO2 · A NO2

[0068] where c NO2 is the molar concentration of nitrite ions (mmol / L), A NO2 is the limiting molar conductivity of nitrite ions (71.5 S-cm 2 / mol), c H = c NO2 .

[0069] 14) C5 - C4 = c H · A H + c NO3 · A NO3

[0070] where c NO3 is the molar concentration of nitrate ions (mmol / L), A NO3For the limit molar conductivity of nitrate (71.0 S·cm 2 / mol), c H = c NO3 ;

[0071] 15) According to the measurement results of C1-C5 and the calculation formula of 10)-14) in the above steps, the content of different anions can be obtained.

[0072] The present application can also be extended to detect and analyze the content of formate, acetate and other anions. Only the corresponding ion selection and screening system needs to be expanded in the system.

[0073] The present application can also detect and analyze the content of cations. Only the anion selection and screening system in the system needs to be replaced with the corresponding cation selection and screening system.

[0074] The anion selection and screening system in the present application is connected in series, and can also be connected in parallel according to the needs.

[0075] Simulation experiment

[0076] The conductivity results measured by the first micro-flow conductivity detection system 6, the second micro-flow conductivity detection system 7, the third micro-flow conductivity detection system 8, the fourth micro-flow conductivity detection system 9 and the fifth micro-flow conductivity detection system 10 are:

[0077] C1=0.085 μS / cm

[0078] C2=0.102 μS / cm

[0079] C3=0.122 μS / cm

[0080] C4=0.14 μS / cm

[0081] C5=0.168 μS / cm

[0082] C1=C 纯水 +c H ·A H +c F ·A F

[0083] C2-C1=c H ·A H +c Cl ·A Cl

[0084] C3-C2=c H ·A H +c SO4 ·A SO4

[0085] C4-C3=cH • A H + c NO2 • A NO2

[0086] C5-C4 = c H • A H + c NO3 • A NO3

[0087] According to the above calculation method, the system can calculate the content of different anions, and the measurement results of the system are as follows:

[0088] The concentration of fluoride ions is 1.43 μg / L

[0089] The concentration of chloride ions is 1.42 μg / L

[0090] The concentration of sulfate ions is 2.46 μg / L

[0091] The concentration of nitrite ions is 3.72 μg / L

[0092] The concentration of nitrate ions is 2.16 μg / L

[0093] At the same time, the test results of the water sample by a third party are as follows:

[0094] The concentration of fluoride ions is 1.40 μg / L

[0095] The concentration of chloride ions is 1.40 μg / L

[0096] The concentration of sulfate ions is 2.43 μg / L

[0097] The concentration of nitrite ions is 3.70 μg / L

[0098] The concentration of nitrate ions is 2.20 μg / L

[0099] By comparing the measurement results of the two systems, it is found that the present application can accurately measure the anion content in the water sample, and has a lower lower limit of detection, and can be used to measure the trace ion content.

[0100] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0101] It should be understood that the application is not limited to the precise construction which has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application should only be limited by the appended claims.

[0102] The above description is only the preferred embodiment of the present application, not any limitation to the present application, any simple modification, change and equivalent structure change of the above embodiment according to the technical essence of the present application are still within the protection scope of the present application technical solution.

Claims

1. A liquid ion chromatography analysis system based on ion selection screening technology, characterized in that: It includes a discharge pipe, a sample output pipe, a fluoride ion selection and screening system (1), a chloride ion selection and screening system (2), a sulfate ion selection and screening system (3), a nitrite ion selection and screening system (4), a nitrate ion selection and screening system (5), an electric automatic regeneration pure water preparation system and a pure water elution pipe; The sample output pipeline is connected to the primary side inlet of the fluoride ion selective screening system (1), the primary side outlet of the fluoride ion selective screening system (1) is connected to the primary side inlet of the chloride ion selective screening system (2), the primary side outlet of the chloride ion selective screening system (2) is connected to the primary side inlet of the sulfate ion selective screening system (3), the primary side outlet of the sulfate ion selective screening system (3) is connected to the primary side inlet of the nitrite ion selective screening system (4), the primary side outlet of the nitrite ion selective screening system (4) is connected to the primary side inlet of the nitrate ion selective screening system (5), and the primary side outlet of the nitrate ion selective screening system (5) is connected to the discharge pipeline; The secondary side outlet of the fluoride ion selective screening system (1) is connected to the inlet of the pure water elution pipeline of the electric automatic regeneration pure water preparation system through the first micro-flow conductivity detection system (6), the secondary side of the chloride ion selective screening system (2), the second micro-flow conductivity detection system (7), the secondary side of the sulfate ion selective screening system (3), the third micro-flow conductivity detection system (8), the secondary side of the nitrite ion selective screening system (4), the fourth micro-flow conductivity detection system (9), the secondary side of the nitrate ion selective screening system (5) and the fifth micro-flow conductivity detection system (10), and the outlet of the pure water elution pipeline is connected to the secondary side inlet of the fluoride ion selective screening system (1).

2. The liquid ion chromatography analysis system based on ion selection screening technology according to claim 1, characterized in that: The primary side and the secondary side of the fluoride ion selective screening system (1) are separated by a fluoride ion selective screening membrane.

3. The liquid ion chromatography analysis system based on ion selection screening technology according to claim 1, characterized in that: The primary side and the secondary side of the chloride ion selective screening system (2) are separated by a chloride ion selective screening membrane.

4. The liquid phase ion chromatography analysis system based on ion selection screening technology according to claim 1, characterized in that: The primary side and the secondary side of the sulfate ion selective screening system (3) are separated by a sulfate ion selective screening membrane.

5. The liquid phase ion chromatography analysis system based on ion selection screening technology according to claim 1, characterized in that: The primary side and the secondary side of the nitrite ion selective screening system (4) are separated by a nitrite ion selective screening membrane.

6. The liquid ion chromatography analysis system based on ion selection screening technology according to claim 1, characterized in that: The primary side and the secondary side of the nitrate ion selective screening system (5) are separated by a nitrate ion selective screening membrane.

7. A liquid ion chromatography analysis method based on ion selection screening technology, characterized in that: The liquid ion chromatography analysis system based on the ion selection screening technology according to claim 1 comprises the following steps: The conductivity detected by the first microfluidic conductivity detection system (6) is C1; The conductivity detected by the second microfluidic conductivity detection system (7) is C2; The conductivity detected by the third microfluidic conductivity detection system (8) is C3; The conductivity detected by the fourth microfluidic conductivity detection system (9) is C4; The conductivity detected by the fifth microfluidic conductivity detection system (10) is C5; The fluoride ion concentration, chloride ion concentration, sulfate ion concentration, nitrite ion concentration, and nitrate ion concentration are calculated based on C1, C2, C3, C4, and C5.

8. The liquid phase ion chromatography analysis method based on ion selective screening technology according to claim 7, characterized in that: C1=C 纯水 +c H ·A H +c F ·A F , where c H is the molar concentration of hydrogen ions, A H is the limiting molar conductivity of hydrogen ions, c F is the molar concentration of fluoride ions, A F is the limiting molar conductivity of fluoride ions, c H =c F ; C2-C1=c H ·A H +c Cl ·A Cl , where c Cl is the molar concentration of chloride ions, A Cl is the limiting molar conductivity of chloride ions, c H =c CL .

9. The liquid phase ion chromatography analysis method based on ion selective screening technology according to claim 8, characterized in that: C3-C2=c H ·A H +c SO4 ·A SO4 , where c SO4 is the molar concentration of sulfate, A SO4 is the limiting molar conductivity of sulfate, c H =2c SO4 ; C4-C3=c H ·A H +c NO2 ·A NO2 , where c NO2 is the molar concentration of nitrite, A NO2 is the limiting molar conductivity of nitrite, c H =c NO2 .

10. The liquid phase ion chromatography analysis method based on ion selection screening technology according to claim 9, characterized in that: C5-C4=c H ·A H +c NO3 ·A NO3 , where c NO3 is the molar concentration of nitrate, A NO3 is the limiting molar conductivity of nitrate, c H =c NO3 .

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