Multi-parameter water quality heavy metal analysis method and device

Abstract

The invention discloses a multi-parameter water quality heavy metal analysis method and device, and the method comprises the following steps: analyzing a to-be-detected water sample by using anodic stripping voltammetry, and respectively determining the lead content, cadmium content and copper content in the to-be-detected water sample; analyzing the to-be-detected water sample by adopting anodic stripping voltammetry, and determining the zinc content in the to-be-detected water sample; in the process of measuring the zinc content in the water sample to be measured, a masking agent containing Ga < 2 + > is added into the water sample to be measured, and the molar ratio of Ga < 2 + > in the added masking agent to copper in the water sample to be measured is (15-20): 1. According to the method, a bivalent Ga < 2 + > solution is added into a reaction system for detecting heavy metals by anodic stripping voltammetry as a masking agent, so that the interference of Cu on Zn in the detection process can be eliminated. According to the method, the masking agent is introduced, so that the four elements, namely lead, cadmium, copper and zinc, in the water sample can be rapidly determined through two-time anodic stripping voltammetry detection.

Description

Technical Field

[0001] The present invention belongs to the field of environmental technology, and in particular relates to a multi-parameter water quality heavy metal analysis method and device. Background Art

[0002] Heavy metals are common contaminants in water quality analysis and can easily enter the human body through bioaccumulation and accumulation, causing damage to tissues and organs. Currently, instruments such as atomic fluorescence, atomic absorption spectroscopy, and inductively coupled plasma-mass spectrometry are not suitable for online analysis of heavy metals in water due to their high cost and operational complexity. Online monitors based on anodic stripping voltammetry offer a rapid approach to heavy metal analysis in water due to their low cost, high sensitivity, and interference resistance.

[0003] Currently, most online water quality analyzers use calibration curves and standard addition methods to detect and analyze test substances. Some solutions also propose updating the automatic calibration cycle after multiple measurement cycles, and using unified blank and standard values ​​to calculate sample test values. However, the systemic heavy metal residues in the measurement process of these methods inevitably lead to large differences in the blank values ​​of the standard and sample measurements, and the final results calculated based on the same blank value also have relatively large deviations. At the same time, the stripping signal of the working electrode based on anodic stripping voltammetry is significantly affected by external conditions. Therefore, inconsistent measurement and calibration conditions and heavy metal residues will inevitably lead to large deviations in the measurement results. In addition, exposure of the working electrode to air and the formation of calomel on the coating surface will affect the stability of the results. Furthermore, most current online monitoring methods based on anodic stripping voltammetry are targeted at a single heavy metal, lacking a method for rapidly detecting multiple heavy metals.

[0004] To quickly and accurately determine multiple heavy metals in water samples, it is necessary to develop anodic stripping voltammetry methods and devices that can simultaneously detect multiple heavy metals. However, during the anodic stripping voltammetry analysis process, Zn and Cu easily form intermetallic compounds within the mercury film, which in turn affects the quantitative analysis of these two metal ions. Therefore, there is currently a lack of anodic stripping voltammetry methods and devices that can quickly detect Zn and Cu in water samples. Summary of the Invention

[0005] In order to overcome the interference between heavy metal element detection and simultaneously detect four heavy metal elements, lead, cadmium, copper and zinc, the present invention proposes a multi-parameter water quality heavy metal analysis method and device. The above purpose can be achieved through the implementation of the following technical solutions: A multi-parameter water quality heavy metal analysis method comprises the following steps: Step 1: Analyze the water sample to be tested by anodic stripping voltammetry to determine the lead content, cadmium content and copper content in the water sample to be tested; Step 2: Analyze the water sample to be tested by anodic stripping voltammetry to determine the zinc content in the water sample to be tested; in the process of determining the zinc content in the water sample to be tested, add Ga-containing 2+ The masking agent, Ga in the added masking agent 2 + The molar ratio of copper to the copper in the water sample to be tested is 15~20:1.

[0006] Optionally, the step 1 specifically includes the following steps: S1: Add electrolyte to the analysis chamber of the three-electrode detection system. The volume of the added electrolyte is V. 电解液 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S2: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the water sample added is V. 水样 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S3: draining the liquid from the analysis chamber of the three-electrode detection system, and then adding the same volume of electrolyte as in S1 to the analysis chamber of the three-electrode detection system; then using the three-electrode detection system to respectively detect the peak heights of the characteristic peaks of lead, cadmium, and copper; S4: Add standard solutions containing known concentrations of lead, cadmium, and copper to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the added standard solution is V. 标液 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S5: According to V 电解液 、 V 水样 、 V 标液 , the concentrations of lead, cadmium and copper in the standard solution and the lead content, cadmium content and copper content calculated from the peak heights of the characteristic peaks of lead, cadmium and copper detected in each of S1 to S4.

[0007] Optionally, the step 2 specifically includes the following steps: S6: Add electrolyte and masking agent to the analysis chamber of the three-electrode detection system. The volume of electrolyte added is 电解液 , the volume of masking agent added is 掩蔽剂 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S7: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the water sample to be tested is 水样 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S8: draining the liquid from the analysis chamber of the three-electrode detection system, and then adding the same volume of electrolyte and masking agent as in S6 to the analysis chamber of the three-electrode detection system; then using the three-electrode detection system to detect the peak height of the characteristic peak of zinc; S9: Add a standard solution containing a known concentration of zinc to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the standard solution added is 锌标液 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S10: According to the peak height of the characteristic peak of zinc detected in each of S6~S9, 电解液 、 掩蔽剂 、 水样 、 锌标液 The zinc content in the water sample was calculated using the zinc content of the standard solution.

[0008] Optionally, the Ga-containing 2+ The masking agent is Ga(NO3)2 solution; and / or In S6 and S8, the Ga 2+ The masking agent is mixed evenly with the electrolyte.

[0009] A multi-parameter water quality heavy metal analysis device, comprising: A three-electrode detection system includes an analysis chamber for holding a sample to be detected; a three-electrode device is provided on the analysis chamber, and the three-electrode device is used to perform anodic stripping voltammetry detection on the sample in the analysis chamber; A pump and valve system is used to add electrolyte, water sample to be tested and masking agent into the analysis chamber; The control system is used to control the three-electrode detection system and the pump and valve system to execute the above-mentioned multi-parameter water quality heavy metal analysis method.

[0010] Optionally, the pump and valve system includes a multi-position valve and a plunger pump; the multi-position valve is connected to a pure water tank via the plunger pump; the multi-position valve is also respectively connected to a waste liquid tank, a standard solution tank, a water sample tank, a masking agent tank, and an electrolyte tank.

[0011] Optionally, the control system includes a mainboard, the mainboard is connected to an electrochemical control module, the electrochemical control module is connected to a three-electrode detection system, and the electrochemical control module is used to control the three-electrode device to perform anodic stripping voltammetry detection on the sample in the analysis chamber; and / or The mainboard is further connected to a pump-valve system control module, which is used to control the pump-valve system to add electrolyte, water sample to be tested and masking agent to the analysis chamber; and / or The mainboard is further connected to a water sample pre-processing control module, which is used to input the water sample to be tested into the multi-parameter water quality and heavy metal analysis device; and / or The mainboard is also connected to a communication port module, and the communication port module is used to output the detection results.

[0012] Optionally, the control system controls the pump valve system to add a water sample to be tested, an electrolyte, and a standard solution containing known concentrations of lead, cadmium, and copper into the analysis chamber; and the control system controls the three-electrode detection system to analyze the water sample using anodic stripping voltammetry to respectively determine the lead content, cadmium content, and copper content in the water sample; Then the control system controls the pump valve system to empty the liquid in the analysis chamber, and adds the water sample to be tested, electrolyte, and Ga-containing solution into the analysis chamber. 2+ and a masking agent and a standard solution containing a known concentration of zinc; and a control system controls a three-electrode detection system to analyze the water sample to be tested using anodic stripping voltammetry to determine the zinc content in the water sample.

[0013] Optionally, the three-electrode device includes a working electrode, a reference electrode and an auxiliary electrode; The working electrode is a glassy carbon electrode, the reference electrode is an Ag / AgCl / saturated KCl electrode, and the auxiliary electrode is a platinum wire electrode.

[0014] The present invention also proposes the application of the multi-parameter water quality heavy metal analysis device in online water quality monitoring.

[0015] Compared with the prior art, the present invention has the following outstanding beneficial effects: The present invention adds divalent Ga into the reaction system of anodic stripping voltammetry for detecting heavy metals. 2+ The solution acts as a masking agent. Since Ga and Cu easily form intermetallic compounds, it can prevent the formation of intermetallic compounds between Zn and Cu during the detection process. 2+ The amount reaches Cu 2+ When the Cu-Zn ratio is 15-20 times that of the Ga-containing 2 + Masking agent can realize the rapid determination of four elements including lead, cadmium, copper and zinc in water samples through two anodic stripping voltammetry tests.

[0016] In the detection method proposed in the present invention, before measuring the element characteristic peaks of the water sample to be tested and the standard solution, the electrolyte blank value is measured once, and after the blank value measurement is completed, the water sample or standard solution is directly added to the electrolyte to detect the characteristic peak. Therefore, each time the characteristic peak height is measured, there is a corresponding blank value, which can eliminate the influence of heavy metal residues in the system to the greatest extent.

[0017] The multi-parameter water quality heavy metal analysis device proposed in the present invention can use the control system to automatically control the three-electrode detection system and the pump and valve system, perform automated detection on the water samples to be tested, and ensure the consistency of the detection conditions during the detection process, avoiding the problem of inaccurate detection caused by inconsistent measurement conditions, thereby improving the accuracy of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Schematic diagram of the multi-parameter water quality heavy metal analysis device of the present invention; Figure 2 This is a schematic diagram of the structure of the three-electrode detection system of the multi-parameter water quality heavy metal analysis device of the present invention; Figure 3 This is a schematic diagram of the pump and valve system structure of the multi-parameter water quality heavy metal analysis device in the present invention.

[0020] Markings in the figure: 1. Analysis chamber, 2. Reference electrode, 3. Working electrode, 4. Auxiliary electrode, 11. Main board, 12. Pump and valve system control module, 13. Electrochemical control module, 14. Water sample pretreatment control module, 15. Communication port module, 16. Plunger pump, 17. Multi-position valve, 18. Three-electrode detection system, 19. Water sample pump, 20. Computer, 30. Liquid storage ring. DETAILED DESCRIPTION

[0021] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0022] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or stated range, and any other stated value or intervening value in the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.

[0024] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0025] A multi-parameter water quality heavy metal analysis method comprises the following steps: Step 1: Analyze the water sample to be tested by anodic stripping voltammetry to determine the lead content, cadmium content and copper content in the water sample to be tested; Step 2: Analyze the water sample to be tested by anodic stripping voltammetry to determine the zinc content in the water sample to be tested; in the process of determining the zinc content in the water sample to be tested, add Ga-containing 2+ The masking agent, Ga in the added masking agent 2 + The molar ratio of copper to the copper in the water sample to be tested is 15~20:1.

[0026] In the analysis process of anodic stripping voltammetry, Zn and Cu easily form intermetallic compounds in the mercury film, thereby affecting the accuracy of quantitative analysis of the two metal ions. 2+ The solution acts as a masking agent. Since Ga and Cu easily form intermetallic compounds, it can prevent the formation of intermetallic compounds between Zn and Cu during the detection process. 2+ The amount reaches Cu 2+ When the Cu-Zn ratio is 15-20 times that of the Ga-containing 2+ Masking agent can realize the rapid determination of four elements including lead, cadmium, copper and zinc in water samples through two anodic stripping voltammetry tests.

[0027] It should be noted that the addition of an electrolyte is required during the analysis of the water sample using anodic stripping voltammetry. Furthermore, a standard solution containing a known concentration of zinc must be tested during the analysis. This standard solution also requires the addition of a masking agent, the amount of which should be the same as that in the water sample.

[0028] In a specific embodiment of the present invention, Ga-containing 2+ The masking agent is first added to the electrolyte containing Ga 2+ Mix the masking agent and then add the water sample to be tested so that the water sample to be tested and the Ga-containing2+ of masking agent mixture.

[0029] Optionally, the step 1 specifically includes the following steps: S1: Add electrolyte to the analysis chamber of the three-electrode detection system. The volume of the added electrolyte is V. 电解液 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S2: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the water sample added is V. 水样 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S3: draining the liquid from the analysis chamber of the three-electrode detection system, and then adding the same volume of electrolyte as in S1 to the analysis chamber of the three-electrode detection system; then using the three-electrode detection system to respectively detect the peak heights of the characteristic peaks of lead, cadmium, and copper; S4: Add standard solutions containing known concentrations of lead, cadmium, and copper to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the added standard solution is V. 标液 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S5: According to V 电解液 、 V 水样 、 V 标液 , the concentrations of lead, cadmium and copper in the standard solution and the lead content, cadmium content and copper content calculated from the peak heights of the characteristic peaks of lead, cadmium and copper detected in each of S1 to S4.

[0030] The step 2 specifically includes the following steps: S6: Add electrolyte and masking agent to the analysis chamber of the three-electrode detection system. The volume of electrolyte added is 电解液 , the volume of masking agent added is 掩蔽剂 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S7: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the water sample to be tested is 水样 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S8: draining the liquid from the analysis chamber of the three-electrode detection system, and then adding the same volume of electrolyte and masking agent as in S6 to the analysis chamber of the three-electrode detection system; then using the three-electrode detection system to detect the peak height of the characteristic peak of zinc; S9: Add a standard solution containing a known concentration of zinc to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the standard solution added is 锌标液 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S10: According to the peak height of the characteristic peak of zinc detected in each of S6~S9, 电解液 、 掩蔽剂 、 水样 、 锌标液 The zinc content in the water sample was calculated using the zinc content of the standard solution.

[0031] Optionally, the Ga-containing 2+ The masking agent is Ga(NO3)2 solution; and / or In S6 and S8, the Ga 2+ The masking agent is mixed evenly with the electrolyte.

[0032] In the above-mentioned detection method proposed by the present invention, before S2, S4, S7, and S9 determine the element characteristic peaks of the water sample to be tested and the standard solution, the electrolyte blank value is determined once (S1, S3, S6, and S8), and after the blank value determination is completed, the water sample or standard solution is directly added to the electrolyte to detect the characteristic peak. Therefore, each time the characteristic peak height is measured, there is a corresponding blank value, which can eliminate the influence of heavy metal residues in the system to the greatest extent.

[0033] Optionally, the lead content, cadmium content and copper content in the water sample are calculated using Formula 1: (Formula 1) In formula 1, b0 is the peak height of the characteristic peak of the corresponding element in S1; b is the peak height of the characteristic peak of the corresponding element in S2; x0 is the peak height of the characteristic peak of the corresponding element in S3; x is the peak height of the characteristic peak of the corresponding element in S4; C 标 is the concentration of the corresponding element in the standard solution; r is the volume coefficient of the water sample, and the calculation method is shown in Formula 2: (Equation 2) is the volume coefficient of the standard solution, and the calculation method is shown in Formula 3: (Formula 3) Alternatively, the zinc content in the water sample is calculated using Formula 4: (Formula 4) In formula 4, is the peak height of the characteristic peak of zinc element in S6; b1 is the peak height of the characteristic peak of zinc element in S7; is the characteristic peak height of zinc element in S8; x1 is the characteristic peak height of zinc element in S9; C Zn标 is the concentration of zinc in the standard solution; is the volume coefficient of the water sample, and the calculation method is shown in Formula 5: (Formula 5) is the volume coefficient of the standard solution, and the calculation method is shown in Formula 6: (Equation 6).

[0034] Optionally, the standard solution is a standard solution containing lead, cadmium, copper and zinc with known concentrations.

[0035] Optionally, the electrolyte can be formed by mixing and diluting a concentrated electrolyte with pure water.

[0036] The present invention also proposes a multi-parameter water quality heavy metal online analysis device, such as Figure 1 Shown, including: A three-electrode detection system includes an analysis chamber for holding a sample to be detected; a three-electrode device is provided on the analysis chamber, and the three-electrode device is used to perform anodic stripping voltammetry detection on the sample in the analysis chamber; A pump and valve system is used to add electrolyte, water sample to be tested and masking agent into the analysis chamber; The control system is used to control the three-electrode detection system and the pump and valve system to execute the above-mentioned multi-parameter water quality heavy metal analysis method.

[0037] The multi-parameter water quality heavy metal online analyzer proposed in the present invention can use a control system to automatically control the three-electrode detection system and the pump and valve system, perform automated detection on the water samples to be tested, and ensure the consistency of detection conditions during the detection process, avoiding the problem of inaccurate detection caused by inconsistent measurement conditions, thereby improving the accuracy of the measurement results.

[0038] The pump and valve system includes a multi-position valve and a plunger pump; the multi-position valve is connected to a pure water tank via the plunger pump; the multi-position valve is also respectively connected to a waste liquid tank, a standard solution tank, a water sample tank, a masking agent tank, and an electrolyte tank.

[0039] The pump-valve system, through the coordination of a multi-position valve and a plunger pump, accurately adds various reagents to the analysis chamber, and also handles cleaning and waste discharge. The control system's automated control of the pump-valve system ensures consistent reaction system composition throughout each test, avoiding inaccurate testing caused by inconsistent reaction system composition.

[0040] Optionally, the pump-valve system is further connected to an air blowing device for blowing air into the analysis chamber to mix the liquid in the analysis chamber.

[0041] Furthermore, the control system includes a mainboard, the mainboard is connected to an electrochemical control module, the electrochemical control module is connected to a three-electrode detection system, and the electrochemical control module is used to control the three-electrode device to perform anodic stripping voltammetry detection on the sample in the analysis chamber; The mainboard is also connected to a pump-valve system control module, which is used to control the pump-valve system to add electrolyte, water sample to be tested and masking agent to the analysis chamber; The mainboard is also connected to a water sample preprocessing control module, which is used to input a water sample to be tested into the multi-parameter online water quality and heavy metal analyzer. The water sample preprocessing control module can be configured to automatically extract a water sample from the water body to be tested and send it to a water sample tank. In some specific embodiments, the water sample preprocessing control module can also perform a preprocessing process such as digestion on the collected water sample before sending it to the water sample tank after preprocessing is completed.

[0042] The mainboard is also connected to a communication port module, and the water sample pre-processing control module is used to output the test results. The test results can be processed and displayed on a test platform or a computer.

[0043] In a specific embodiment, the control system controls the pump valve system to add a water sample to be tested, an electrolyte, and a standard solution containing known concentrations of lead, cadmium, and copper into the analysis chamber; and the control system controls the three-electrode detection system to analyze the water sample using anodic stripping voltammetry to respectively determine the lead content, cadmium content, and copper content in the water sample; Then the control system controls the pump valve system to empty the liquid in the analysis chamber, and adds the water sample to be tested, electrolyte, and Ga-containing solution into the analysis chamber. 2+ and a masking agent and a standard solution containing a known concentration of zinc; and a control system controls a three-electrode detection system to analyze the water sample to be tested using anodic stripping voltammetry to determine the zinc content in the water sample.

[0044] Furthermore, during the detection process, each time the liquid in the analysis chamber is emptied, the pump valve system draws pure water from the pure water tank and injects pure water into the analysis chamber for cleaning, and the waste liquid after cleaning is discharged into the waste liquid tank.

[0045] Optionally, the three-electrode device includes a working electrode, a reference electrode and an auxiliary electrode; The working electrode is a glassy carbon electrode, the reference electrode is an Ag / AgCl / saturated KCl electrode, and the auxiliary electrode is a platinum wire electrode.

[0046] The present invention also proposes the application of the above-mentioned multi-parameter water quality heavy metal online analysis device in water quality online monitoring.

[0047] The device of the present invention can rapidly determine the four elements (lead, cadmium, copper, and zinc) in water samples through double anodic stripping voltammetry, with high detection speed. Furthermore, by automatically controlling the detection conditions, the detection results are accurate, making it very suitable for online water quality monitoring.

[0048] Specific embodiments of the present invention are described below with reference to the accompanying drawings. The embodiments are merely examples for the purpose of clear description and are not intended to limit the implementation methods.

[0049] Example 1 Accurately measure the standard substance / medium for lead solution in water (5% nitric acid GBW(E)082825, 1000 mg / L); the standard substance / medium for cadmium solution in water (5% nitric acid GBW(E)082822, 1000 mg / L); copper sulfate pentahydrate; and zinc nitrate hexahydrate. Dissolve them in deionized water to volume to prepare a standard solution containing lead, cadmium, copper, and zinc. The concentration of each standard solution is 200 μg / L. A portion of these standard solutions is used as the sample to be tested. An electrolyte is prepared containing 20 g / L of anhydrous sodium acetate, 5% glacial acetic acid, and 0.02 g / L of bismuth nitrate pentahydrate. A masking agent is prepared: Ga(NO₃)₂ at a concentration of 20 mg / L. The characteristic dissolution potentials detected by the three-electrode detection system are 0.6 V for Pb, 0.76 V for Cd, 0.25 V for Cu, and 1.15 V for Zn.

[0050] Follow the steps below to determine the heavy metal content in the sample: S1: Add electrolyte to the analysis chamber of the three-electrode detection system. The volume of electrolyte added is V. 电解液 The concentration of the sample was 1000uL; a three-electrode detection system was then used to detect the characteristic peak heights of lead, cadmium and copper respectively; S2: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the added water sample is V. 水样 The concentration of lead, cadmium and copper was 4000uL; a three-electrode detection system was then used to detect the characteristic peak heights of lead, cadmium and copper respectively; S3: Drain the liquid from the analysis chamber of the three-electrode detection system, and then add an electrolyte with a volume equal to that in S1 to the analysis chamber of the three-electrode detection system; then use the three-electrode detection system to detect the peak heights of the characteristic peaks of lead, cadmium, and copper respectively; S4: Add standard solutions containing known concentrations of lead, cadmium, and copper to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the added standard solution is V. 标液 The concentration of lead, cadmium and copper was 4000uL; a three-electrode detection system was then used to detect the characteristic peak heights of lead, cadmium and copper respectively; S5: According to V 电解液 、V 水样 、V 标液 The lead, cadmium, and copper concentrations in the standard solution and the lead, cadmium, and copper content were calculated from the peak heights of the characteristic lead, cadmium, and copper peaks detected in each of S1 to S4. The calculated lead, cadmium, and copper contents in the water sample were 198ug / L, 202ug / L, and 204ug / L, respectively. S6: Add electrolyte and masking agent to the analysis chamber of the three-electrode detection system. The volume of electrolyte added is 电解液 The volume of masking agent added is 1000uL 掩蔽剂 The concentration of zinc was 650uL; the characteristic peak height of zinc was detected using a three-electrode detection system; S7: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the water sample added is 水样 The concentration of the solution was 4000uL; the characteristic peak height of zinc was detected using a three-electrode detection system; S8: draining the liquid from the analysis chamber of the three-electrode detection system, and then adding the same volume of electrolyte and masking agent as in S6 to the analysis chamber of the three-electrode detection system; then using the three-electrode detection system to detect the peak height of the characteristic peak of zinc; S9: Add a standard solution containing a known concentration of zinc to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the standard solution added is 锌标液 The concentration of the sample was 4000ul; the peak height of the characteristic peak of zinc was detected using a three-electrode detection system; S10: According to the peak height of the characteristic peak of zinc detected in each of S6~S9 电解液 、 掩蔽剂 、 水样 、 锌标液 The zinc content in the water sample was calculated based on the zinc content of the standard solution. The calculated zinc content in the water sample was 202ug / L.

[0051] Example 2 The present invention also proposes a multi-parameter water quality heavy metal online analysis device to implement the above method. The device includes: like Figure 2The three-electrode detection system 18 shown in the figure includes an analysis chamber 1 for holding the sample to be detected; a three-electrode device is provided on the analysis chamber, and the three-electrode device is used to perform anodic stripping voltammetry detection on the sample to be detected in the analysis chamber; the three-electrode device includes a working electrode 3, a reference electrode 2 and an auxiliary electrode 4; wherein the working electrode 3 is a glassy carbon electrode, the reference electrode 2 is an Ag / AgCl / saturated KCl electrode, and the auxiliary electrode 4 is a platinum wire electrode.

[0052] a pump-valve system for adding electrolyte, water sample, and masking agent to the analysis chamber; The control system is used to control the three-electrode detection system and the pump-valve system to execute the multi-parameter water quality heavy metal analysis method described in Example 1.

[0053] like Figure 1 、 Figure 2 and Figure 3 As shown, the pump and valve system includes a multi-position valve 17 and a plunger pump 16; the multi-position valve 17 is connected to a pure water tank through a liquid storage ring 30 and a plunger pump 16 in sequence; the multi-position valve 17 is also connected to a waste liquid tank, a standard solution tank, a water sample tank, a masking agent tank, and an electrolyte tank.

[0054] The control system includes a main board 11, the main board 11 is connected to an electrochemical control module 13, the electrochemical control module 13 is connected to a three-electrode detection system, and the electrochemical control module 13 is used to control the three-electrode detection system 18 to perform anodic stripping voltammetry on the sample to be detected in the analysis chamber; and / or The main board 11 is further connected to a pump-valve system control module 12, which is used to control the pump-valve system to add electrolyte, water sample and masking agent to the analysis chamber; and / or The main board 11 is also connected to a water sample pre-processing control module 14, which is used to control a water sample pump 19 to input the water sample to be tested into the multi-parameter water quality heavy metal analysis device; The mainboard 11 is further connected to a communication port module 15 , which is used to output the detection results to a platform or a computer 20 .

[0055] The control system performs the following steps to perform multi-parameter water quality heavy metal analysis: The control system controls the pump and valve system to add the water sample to be tested, the electrolyte, and the standard solution containing known concentrations of lead, cadmium, and copper into the analysis chamber; the control system also controls the three-electrode detection system 18 to analyze the water sample using anodic stripping voltammetry, executing the processes S1 to S5 in the above embodiment 1 to respectively determine the lead content, cadmium content, and copper content in the water sample; and controls the communication port module 15 to output the test results of the lead content, cadmium content, and copper content.

[0056] Then the control system controls the pump valve system to empty the liquid in the analysis chamber, and adds the water sample to be tested, electrolyte, and Ga-containing solution into the analysis chamber. 2+ The control system controls the three-electrode detection system 18 to analyze the water sample using anodic stripping voltammetry, executing steps S6 to S10 in Example 1 above, and determining the zinc content in the water sample. The control system also controls the communication port module 15 to output the zinc content detection result.

[0057] Comparative Example 1 Compared to Example 1, this comparative example did not add a masking agent, resulting in a measured zinc content of 182 μg / L in the water sample. In the absence of a masking agent, Zn and Cu readily form intermetallic compounds within the mercury film, thereby affecting the accuracy of the quantitative analysis of Zn ions.

[0058] Comparative Example 2 Compared with Example 1, the amount of masking agent added in step S7 was reduced to 200 μL in this comparative example. The zinc content in the water sample was measured to be 191 μg / L. This was due to insufficient masking agent, resulting in incomplete masking.

[0059] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A multi-parameter water quality heavy metal analysis method, characterized in that: The steps include: Step 1: Analyze the water sample to be tested by anodic stripping voltammetry to determine the lead content, cadmium content and copper content in the water sample to be tested; Step 2: Analyze the water sample to be tested by anodic stripping voltammetry to determine the zinc content in the water sample to be tested; in the process of determining the zinc content in the water sample to be tested, add Ga-containing 2+ The masking agent, Ga in the added masking agent 2+ The molar ratio of copper to the copper in the water sample to be tested is 15~20:

1.

2. The multi-parameter water quality heavy metal analysis method according to claim 1, characterized in that: The step 1 specifically includes the following steps: S1: Add electrolyte to the analysis chamber of the three-electrode detection system. The volume of the added electrolyte is V. 电解液 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S2: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the water sample added is V. 水样 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S3: draining the liquid from the analysis chamber of the three-electrode detection system, and then adding the same volume of electrolyte as in S1 to the analysis chamber of the three-electrode detection system; then using the three-electrode detection system to respectively detect the peak heights of the characteristic peaks of lead, cadmium, and copper; S4: Add standard solutions containing known concentrations of lead, cadmium, and copper to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the added standard solution is V. 标液 ; Then a three-electrode detection system was used to detect the characteristic peak heights of lead, cadmium and copper respectively; S5: According to V 电解液 、 V 水样 、 V 标液 , the concentrations of lead, cadmium and copper in the standard solution and the lead content, cadmium content and copper content calculated from the peak heights of the characteristic peaks of lead, cadmium and copper detected in each of S1 to S4.

3. The multi-parameter water quality heavy metal analysis method according to claim 1, characterized in that: The step 2 specifically includes the following steps: S6: Add electrolyte and masking agent to the analysis chamber of the three-electrode detection system. The volume of electrolyte added is 电解液 , the volume of masking agent added is 掩蔽剂 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S7: Add the water sample to be tested into the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the water sample to be tested is 水样 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S8: draining the liquid from the analysis chamber of the three-electrode detection system, and then adding the same volume of electrolyte and masking agent as in S6 to the analysis chamber of the three-electrode detection system; then using the three-electrode detection system to detect the peak height of the characteristic peak of zinc; S9: Add a standard solution containing a known concentration of zinc to the electrolyte in the analysis chamber of the three-electrode detection system. The volume of the standard solution added is 锌标液 ; Then a three-electrode detection system is used to detect the peak height of the characteristic peak of zinc; S10: According to the peak height of the characteristic peak of zinc detected in each of S6~S9, 电解液 、 掩蔽剂 、 水样 、 锌标液 The zinc content in the water sample was calculated using the zinc content of the standard solution.

4. The multi-parameter water quality heavy metal analysis method according to claim 3, characterized in that: The Ga-containing 2+ The masking agent is Ga(NO3)2 solution; and / or In S6 and S8, the Ga 2+ The masking agent is mixed evenly with the electrolyte.

5. A multi-parameter water quality heavy metal analysis device, characterized in that: include: A three-electrode detection system, the three-electrode detection system comprising an analysis chamber for holding a sample to be detected; The analysis chamber is provided with a three-electrode device, which is used to perform anodic stripping voltammetry detection on the sample in the analysis chamber; A pump and valve system is used to add electrolyte, water sample to be tested and masking agent into the analysis chamber; A control system for controlling a three-electrode detection system and a pump-valve system to execute the multi-parameter water quality heavy metal analysis method according to any one of claims 1 to 4.

6. The multi-parameter water quality heavy metal analysis device according to claim 5, characterized in that: The pump and valve system includes a multi-position valve and a plunger pump; the multi-position valve is connected to a pure water tank via the plunger pump; the multi-position valve is also respectively connected to a waste liquid tank, a standard solution tank, a water sample tank, a masking agent tank, and an electrolyte tank.

7. The multi-parameter water quality heavy metal analysis device according to claim 5, characterized in that: The control system includes a mainboard, the mainboard is connected to an electrochemical control module, the electrochemical control module is connected to a three-electrode detection system, and the electrochemical control module is used to control the three-electrode device to perform anodic stripping voltammetry detection on the sample in the analysis chamber; and / or The mainboard is further connected to a pump-valve system control module, which is used to control the pump-valve system to add electrolyte, water sample to be tested and masking agent to the analysis chamber; and / or The mainboard is further connected to a water sample pre-processing control module, which is used to input the water sample to be tested into the multi-parameter water quality and heavy metal analysis device; and / or The mainboard is also connected to a communication port module, and the communication port module is used to output the detection results.

8. The multi-parameter water quality heavy metal analysis device according to claim 5, characterized in that: The control system controls the pump and valve system to add a water sample to be tested, an electrolyte, and a standard solution containing known concentrations of lead, cadmium, and copper into the analysis chamber; and the control system controls the three-electrode detection system to analyze the water sample using anodic stripping voltammetry to respectively determine the lead content, cadmium content, and copper content in the water sample; Then the control system controls the pump valve system to empty the liquid in the analysis chamber, and adds the water sample to be tested, electrolyte, and Ga-containing solution into the analysis chamber. 2+ and a masking agent and a standard solution containing a known concentration of zinc; and a control system controls a three-electrode detection system to analyze the water sample to be tested using anodic stripping voltammetry to determine the zinc content in the water sample.

9. The multi-parameter water quality heavy metal analysis device according to claim 5, characterized in that: The three-electrode device includes a working electrode, a reference electrode and an auxiliary electrode; The working electrode is a glassy carbon electrode, the reference electrode is an Ag / AgCl / saturated KCl electrode, and the auxiliary electrode is a platinum wire electrode.

10. Use of the multi-parameter water quality heavy metal analyzer according to any one of claims 5 to 9 in online water quality monitoring.

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