Multi-channel water quality heavy metal ion detection device and detection method thereof
By adopting ion-sensitive sensors and multi-channel parallel structure design in heavy metal online detection equipment, the problem of limited detection is solved, the detection accuracy and anti-interference ability of multiple heavy metals is improved, the detection cost is reduced, and multiple realizations are achieved High accuracy of online detection of heavy metal ions.
Patent Information
- Application Number
- CN202411462416.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2024-12-20
AI Technical Summary
The existing online heavy metal detection equipment has the problem that a single detection can only detect one ion, poor anti-interference ability, and high cost of multiple heavy metal detection equipment at the same time.
The ion-sensitive sensor - a load ion-sensitive membrane material is used, combined with multi-channel parallel structure design and electrochemical detection principles, to achieve high accuracy detection of multiple heavy metal ions.
It realizes low-cost, simultaneous measurement of multiple heavy metal ions and anti-interference, improves detection accuracy, and is suitable for online detection.
Smart Images
Figure CN119165028A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of heavy metal online detection. Background Art
[0002] Existing heavy metal online detection equipment usually adopts spectrophotometry and electrochemical methods. Spectrophotometry is the most widely used. Its design is based on the reaction of certain heavy metal ions with specific chemical substances to generate colored substances, and quantitative analysis is performed according to Lambert-Beer's law. The principle of this method is simple, and the online design technology of spectrophotometry is also very mature, but this method generally can only measure one ion with one device. At present, the detection limit of the water quality heavy metal online detector based on the principle of spectrophotometry is generally 10μg / L, which is difficult to meet the low concentration detection occasions. Turbidity and color interfere with the quantification of colored substances and thus affect the accuracy of the measurement results. In addition, the interference between ions cannot be ignored. For example, dithizone is needed to detect lead, but dithizone itself reacts chemically with various other heavy metals such as zinc, copper, and nickel to generate chemical substances of other colors. Therefore, it is difficult to qualitatively and quantitatively analyze water samples using only dithizone. Therefore, it has the problems of low sensitivity, colorimetric and turbidity interference, interference between metal ions, and high risk of secondary products.
[0003] The electrochemical method is an important detection technology for environmental testing. The detection of heavy metals in water is based on the electrical changes caused by the chemical reaction process on the electrode surface. It is an important detection technology for environmental testing. The detection of heavy metals in water quality mainly uses anodic stripping voltammetry and catalytic polarography. The electrochemical method has a relatively high sensitivity and the detection limit can reach ug / L or even lower. It can be used in low-concentration heavy metal ion occasions such as surface water, drinking water, and drainage. Since the essence of electrochemical detection is the mass transfer process of ion polarity on the electrode surface, and complex water bodies contain various cations in addition to the target detection ions, there is also the problem of ion interference. Although adding masking agents can play a certain role, the water quality of environmental water bodies and polluted outlets is often more complicated and cannot completely mask the interference between ions. The electrochemical method has a relatively high sensitivity and can be used in low-concentration heavy metal ion occasions such as surface water, groundwater, drinking water, and drainage. However, the electrochemical method uses mercury film electrodes and dropping mercury electrodes, which have secondary pollution problems; At the same time, there is also the problem of ion interference. Although adding masking agents can play a certain role, the water quality of environmental water bodies and polluted outlets is often more complicated and cannot completely mask the interference between ions.
[0004] Inductively coupled mass spectrometry (ICP-MS) uses a high-frequency radio frequency signal applied to an inductive coil to form a high-temperature plasma inside the coil. The carrier gas and the atomized sample are decomposed, excited, and ionized in the plasma torch area. After the positive ions are formed, they enter the mass spectrometer through the interface and are qualitatively and quantitatively analyzed by the mass-to-nuclear ratio. This method has high sensitivity (the detection limit can reach pg / L) and can detect multiple heavy metal ions at the same time. Different heavy metal ions have different mass-to-nuclear ratios and there is no interference between ions. However, the principle of ICPMS is complicated, so it is expensive and requires high operating skills. In addition, the use of carrier gas consumes a lot of online use. For in-situ measurements in remote areas, ICP-MS technology is not applicable.
[0005] X-ray fluorescence spectrometry (XRF) uses an atomizer to atomize the water sample, and then uses an X-ray fluorescence spectrometer to measure it after enrichment. The measurement principle is that the ground state atoms absorb radiation of a suitable specific frequency and are excited to a high energy state, and then emit X-ray fluorescence of a characteristic wavelength in the form of light radiation during the excitation process for qualitative and quantitative analysis. XRF can also detect a variety of heavy metal ions with high sensitivity. Since the X-rays generated by the transition and excitation of each metal ion are specific, there is no problem of interference between ions, but its equipment is also expensive and requires carrier gas.
[0006] Spectrophotometry and electrochemical methods usually use one device to detect a single factor indicator. For situations where multiple factors are required to be detected, multiple detection devices are usually required. Among them, although traditional electrochemical electrodes can be used to simultaneously determine multiple heavy metal ions, there is a big difference between the determination of a certain heavy metal ion using a mixed standard solution and the determination of a single standard heavy metal ion, which often leads to inaccurate tests in actual applications. At present, online water quality detection equipment such as inductively coupled mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF) have appeared on the market, which can detect multiple heavy metal ions at the same time, with high sensitivity and low interference between ions. However, they are usually expensive and complex to maintain, and have high requirements for personnel operation, so they are not widely used.
[0007] In summary, the prior art has the following defects:
[0008] 1) A single test can only detect one or a few ions: The existing spectrophotometric heavy metal detection equipment can only detect one ion; electrochemical heavy metal online detection equipment has ion interference for multiple ions, and generally detects a single ion. It is difficult to guarantee accuracy when measuring multiple ions at the same time.
[0009] 2) Poor anti-interference ability: Spectrophotometry and traditional electrochemical methods have interference between ions, which affects the detection accuracy.
[0010] 3) The cost of online application of equipment for simultaneous detection of multiple heavy metals is high: I CP-MS and XRF technology can detect multiple heavy metal ions online at the same time, but the cost is high. The use of carrier gas also makes its operation and maintenance costs high. Due to the high complexity of the equipment, the difficulty of operation and maintenance technology is high, the maintenance is complex, and professional technicians are required, which makes it difficult to apply online. Summary of the invention
[0011] The present invention adopts an ion-sensitive sensor - loaded ion-sensitive membrane material. The ion-sensitive membrane material can specifically select a certain heavy metal ion, utilizes a multi-channel parallel structural design and electrochemical detection principles, and uses different ion-sensitive membrane electrodes in different channels to achieve simultaneous high-accuracy detection of multiple heavy metal ions.
[0012] The present invention provides a multi-channel water quality heavy metal ion detection device, comprising: a quantitative unit, a multi-way valve, a precision injector, a reaction pool, a circulation pump, a multi-way valve 1, an ion-sensitive sensor, a multi-way valve 2, and a detection device; the quantitative unit is provided with a liquid extraction port; the multi-way valve comprises 9 independent interfaces, namely a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface, an eighth interface, and a ninth interface; the precision injector is provided with an injection port and an outlet port; the liquid extraction port of the quantitative unit is connected to the first interface of the multi-way valve; the multi-way valve 1 comprises 5 inlets and 1 common port; the multi-way valve 1 comprises 5 inlets and 1 common port; the reaction pool is provided with three injection ports and one liquid discharge port, the three The sample inlet is respectively connected with the ninth interface of the multi-way valve, the sample outlet of the precision sample injector, the common port of the multi-way valve 2 and the inlet of the circulation pump; the circulation pump is provided with an inlet and an outlet, and the outlet of the circulation pump 14 is connected with the common port of the multi-way valve 15; the ion-sensitive sensor comprises: 5 channels, a working electrode, a reference electrode and an auxiliary electrode; the microchannel pressing block has 5 micro chambers; the chamber is arranged in the middle of each channel, and the lower inlet and the upper outlet of the channel are arranged at both ends of the chamber; the lower inlet of each channel is connected with the outlet of the multi-way valve 1, and the upper outlet of the channel is connected with the inlet of the multi-way valve 2; the detection device is respectively connected with the working electrode, the reference electrode and the auxiliary electrode.
[0013] Furthermore, it also includes: a standard solution bottle; the standard solution bottle is connected to the precision sample injector.
[0014] Furthermore, a stirring device is provided in the reaction tank.
[0015] Furthermore, it also includes: a waste liquid barrel, which is respectively connected to the eighth interface of the multi-way valve and the discharge port of the reaction tank.
[0016] Furthermore, a drain valve is provided on the connecting pipe between the waste liquid barrel and the reaction tank.
[0017] Furthermore, it also includes: reagent bottle one, reagent bottle two, reagent bottle three, a cleaning bottle, and a water sample cup; the third interface of the multi-way valve is connected to reagent bottle one through a pipeline; the fourth interface of the multi-way valve is connected to reagent bottle two through a pipeline; the fifth interface of the multi-way valve is connected to reagent bottle three through a pipeline; the sixth interface of the multi-way valve is connected to the cleaning bottle through a pipeline; and the seventh interface of the multi-way valve is connected to the water sample cup through a pipeline.
[0018] Furthermore, membranes of different heavy metal ions are arranged on the working electrode.
[0019] The present invention also provides a multi-channel water quality heavy metal ion detection method, comprising the following steps: first, cleaning; the cleaning comprises: the quantitative unit extracts cleaning water into the reaction pool, the stirring device starts stirring to clean the reaction pool, the stirring device stops working, the circulating pump passes the cleaning water in the reaction pool through the multi-way valve 1, the ion-sensitive sensor channel, and the multi-way valve 2, and the cleaning water is discharged to the waste liquid bucket through the drain valve; second, detecting the dissolution current baseline signal of the test liquid; the detection of the dissolution current baseline signal of the test liquid comprises: the quantitative unit extracts the test liquid of reagent 1 or reagent 2 or reagent 3 into the reaction pool, the stirring device mixes the reaction pool liquid, the stirring device stops working after mixing, the circulating pump circulates the test liquid to the ion-sensitive sensor channel, and the working electrode applies a constant voltage to enrich After a certain period of time, a reverse voltage is applied to the heavy metal ions to dissolve from the ion sensitive membrane, and the detection unit detects the dissolution current baseline signal; the third detection standard solution dissolution current baseline signal; the detection standard solution dissolution current baseline signal includes: a precision sampler extracts a quantitative heavy metal standard solution into a reaction tank, a stirring device mixes the reaction tank liquid, the stirring device stops working after mixing, and the circulation pump is turned on. The circulation pump circulates the standard solution to the ion sensitive sensor channel, and after a certain period of time, a constant voltage is applied to the working electrode to enrich, and then a reverse voltage is applied to the heavy metal ions to dissolve from the ion sensitive membrane, and the detection unit detects the dissolution current signal of the standard solution; fourth, according to the dissolution current baseline signal of the test solution and the dissolution current baseline signal of the standard solution, the concentration of the heavy metal ions to be measured in the water sample is obtained.
[0020] The solution of the present invention aims at solving the problems that existing electrochemical online detection instruments cannot measure multiple ions simultaneously and have poor anti-interference ability. By utilizing ion sensitive membranes and multi-channel design, the online detection purposes of low cost, simultaneous measurement of multiple heavy metal ions, anti-interference and improved detection accuracy are achieved. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a diagram of a multi-channel water quality heavy metal ion detection device.
[0022] Figure 2This is a structural diagram of a multi-channel ion-sensitive sensor.
[0023] Figure 3 This is the plan view of the multi-channel ion sensitive sensor circuit board. DETAILED DESCRIPTION
[0024] The present invention can solve one or more of the above problems. It uses an ion-sensitive sensor - loaded with ion-sensitive membrane materials, which can specifically select certain heavy metal ions, and uses a multi-channel parallel structural design and electrochemical detection principles to achieve high-accuracy detection of multiple heavy metal ions simultaneously using different ion-sensitive membrane electrodes in different channels.
[0025] Multi-channel parallelism: Multiple substances are tested simultaneously on multiple parallel channels.
[0026] Ion-sensitive sensor: an electrode structure loaded with ion-sensitive membrane material.
[0027] Example
[0028] The present invention provides a multi-channel ion-sensitive sensor water quality heavy metal ion simultaneous online detection system, comprising: a quantitative unit 1, a multi-way valve 2, a reagent bottle 1 3, a reagent bottle 2 4, a reagent bottle 3 5, a cleaning bottle 6, a water sample cup 7, a waste liquid bucket 8, a standard liquid bottle 9, a precision injector 10, a reaction pool 11, a stirring device 12, a drain valve 13, a circulation pump 14, a multi-way valve 1 15, an ion-sensitive sensor 16, a multi-way valve 2 17, and a detection device 18.
[0029] The quantitative unit 1 is composed of a peristaltic pump and a photoelectric quantitative device. The peristaltic pump draws liquid to a photoelectric quantitative sensor and stops to quantitatively extract liquid. The quantitative unit 1 is provided with a liquid extraction port, and the liquid extraction port of the quantitative unit 1 is connected to the first interface 021 of the multi-way valve 2 through a pipeline.
[0030] The multi-way valve 2 includes 9 independent interfaces, namely a first interface 021 , a second interface 022 , a third interface 023 , a fourth interface 024 , a fifth interface 025 , a sixth interface 026 , a seventh interface 027 , an eighth interface 028 , and a ninth interface 029 . The second interface 022 of the multi-way valve 2 is connected to the air through a pipeline, the third interface 023 of the multi-way valve 2 is connected to the reagent bottle 1 3 through a pipeline, and the reagent bottle 1 contains the reagent 1; the fourth interface 024 of the multi-way valve 2 is connected to the reagent bottle 2 4 through a pipeline, and the reagent bottle 2 contains the reagent 2; the fifth interface 025 of the multi-way valve 2 is connected to the reagent bottle 3 5 through a pipeline, and the reagent bottle 3 contains the reagent 3; the sixth interface 026 of the multi-way valve 2 is connected to the cleaning bottle 6 through a pipeline, and the cleaning bottle contains cleaning water, which should generally be ultrapure water; the seventh interface 027 of the multi-way valve 2 is connected to the water sample cup 7 through a pipeline, and the water sample cup contains the sample to be tested; the eighth interface 028 of the multi-way valve 2 is connected to the waste liquid barrel 8 through a pipeline, and the waste liquid barrel is used to hold wastewater and waste liquid; the ninth interface 029 of the multi-way valve 2 is connected to the reaction pool 11 through a pipeline; the multi-way valve realizes the extraction and discharge of air, reagents, water samples, cleaning water and the discharge of waste liquid through a switching valve.
[0031] The waste liquid barrel 8 is connected to the eighth interface 028 of the multi-way valve.
[0032] The reaction pool 11 is provided with three injection ports at the top and a discharge port at the bottom; the discharge port is connected to the discharge valve 13 through a pipeline, and the discharge valve 13 is connected to the waste liquid bucket 8 through a pipeline. After the valve is opened, the liquid in the reaction pool is discharged into the waste liquid bucket by gravity. The three injection ports of the reaction pool 11 are respectively connected with the ninth interface 029 of the multi-way valve, the sample outlet of the precision injector 10, the common port of the multi-way valve 2 and the inlet of the circulating pump 14. The reaction pool 11 is also connected to the waste liquid bucket 8 through the discharge valve 13. A stirring device 12 is also provided in the reaction pool 11. The stirring device 12 is composed of a motor and a stirrer, the stirrer is placed inside the reaction pool 11, and the stirring motor is arranged at the bottom of the reaction pool. The stirring motor rotates to drive the stirrer to rotate, so that the liquid is mixed and flows in the reaction pool.
[0033] The precision sampler 10 is composed of a valve and an injection pump or a plunger pump. The precision sampler is provided with an inlet and an outlet. The inlet of the precision sampler 10 is connected to the standard solution bottle 9 through a pipeline, and the outlet of the precision sampler 10 is connected to the first inlet of the reaction tank 11 through a pipeline. The inlet and the outlet are connected to the injection pump or the plunger pump through a valve. When the injection pump or the plunger pump extracts, the valve opens the inlet to extract the standard solution. When the injection pump or the plunger pump discharges, the valve opens the outlet to discharge the liquid into the reaction tank 11.
[0034] The circulation pump 14 is provided with an inlet and an outlet. The inlet of the circulation pump 14 is connected to the third sample inlet of the reaction pool 11 through a pipeline. The pipeline should be inserted into the bottom of the reaction pool 11 and should not hinder the operation of the stirring device 12. The outlet of the circulation pump 14 is connected to the common port of the multi-way valve 15 through a pipeline. The multi-way valve 15 includes 5 outlets and 1 common port, which are the first outlet 151, the second outlet 152, the third outlet 153, the fourth outlet 154, and the fifth outlet 155; the common port is the inlet interface. The common port of the multi-way valve 15 is connected to the outlet of the circulation pump 14; each outlet is connected to the lower end inlet of the corresponding channel of the ion-sensitive sensor. The outlet 151 of the multi-way valve 15 is connected to the lower inlet of the channel 161 of the ion-sensitive sensor 16 through a pipeline, and the upper outlet of the channel 161 of the ion-sensitive sensor 16 is connected to the inlet 171 of the multi-way valve 17 through a pipeline; the outlet 152 of the multi-way valve 15 is connected to the lower inlet of the channel 162 of the ion-sensitive sensor 16 through a pipeline, and the upper outlet of the channel 162 of the ion-sensitive sensor 16 is connected to the inlet 172 of the multi-way valve 17 through a pipeline; the outlet 153 of the multi-way valve 15 is connected to the lower inlet of the channel 163 of the ion-sensitive sensor 16 through a pipeline, and the upper outlet of the channel 163 of the ion-sensitive sensor 16 is connected to the inlet 171 of the multi-way valve 17 through a pipeline. The pipeline is connected to the inlet 173 of the multi-way valve 17; the outlet 154 of the multi-way valve 15 is connected to the lower inlet of the channel 164 of the ion-sensitive sensor 16 through the pipeline, and the upper outlet of the channel 164 of the ion-sensitive sensor 16 is connected to the inlet 174 of the multi-way valve 17 through the pipeline; the outlet 155 of the multi-way valve 15 is connected to the lower inlet of the channel 165 of the ion-sensitive sensor 16 through the pipeline, and the upper outlet of the channel 165 of the ion-sensitive sensor 16 is connected to the inlet 175 of the multi-way valve 17 through the pipeline; that is, the multi-way valve 15, the ion-sensitive sensor 16 and the multi-way valve 17 correspond one to one, so that the valve is opened to realize the connection of a certain channel.
[0035] The ion-sensitive sensor 16 includes 5 channels, namely the first channel 161, the second channel 162, the third channel 163, the fourth channel 164, and the fifth channel 165; each channel is provided with a lower inlet and an upper outlet; the lower inlet of each channel is connected to the outlet of the multi-way valve 1, and the upper outlet of the channel is connected to the inlet of the multi-way valve 2. The ion-sensitive sensor 16 also includes: an electrode shell 19, a working electrode 20, a pressing block 21, a first O-ring 22, a circuit board 23, a reference electrode 24, an auxiliary electrode 25, a second O-ring 26, and a microchannel pressing block 27. The working electrode is provided with a membrane of different heavy metal ions. The ion-sensitive sensor is composed of an electrode shell 19, a working electrode 20, a pressing block 21, a first O-ring 22, a circuit board 23, a reference electrode 24, an auxiliary electrode 25, a second O-ring 26, a microchannel pressing block 27, and an ion-sensitive membrane material. The working electrode 20 is connected to the detection device through the exposed copper column wire on the top of the electrode shell 19, and the bottom is covered with the working electrode 20 and the lower plane of the working electrode is flush with the lower plane of the electrode shell. The working electrode 20 is an electrode that directly participates in the electrochemical reaction, and the lower surface of the working electrode is covered with an ion-sensitive membrane material by drip coating or electroplating. The lower part of the electrode shell 19 has an external thread. The interface with internal threads at multiple positions is used to rotate the electrode shell 19 to the pressing block 21 through a threaded connection until the lower end of the working electrode 20 extends out of the thickness of the circuit board 23. The pressing block 21 and the circuit board 23 are fixedly connected as a whole; the first O-ring 22 is put on the bottom of the electrode shell 19, and the protruding part of the working electrode is just stuck in the central through hole of the auxiliary electrode 25. The microchannel pressing block 27 has 5 micro chambers, and the second O-ring 26 is pressed around the top of the chamber. The pressing block 21, the first O-ring 22, the circuit board 23, the second O-ring 26, and the microchannel pressing block 27 are pressed tightly by screws. The upper part of each micro chamber is provided with a corresponding auxiliary electrode 25 and a working electrode 20. The first and second O-rings shown play a sealing role at the joint; the first channel 161, the second channel 162, the third channel 163, the fourth channel 164, and the fifth channel 165 of the ion-sensitive sensor with inlet and outlet ports are provided at both ends of the chamber. An annular auxiliary electrode 25 is welded on the circuit board 23, and the auxiliary electrode and the working electrode form a loop to drive the electrochemical reaction. The circuit board 23 is also bonded with a solid reference electrode 24 next to each auxiliary electrode 25. The reference electrode provides a stable potential reference for measuring the potential of the working electrode. The auxiliary electrode and the reference electrode are connected to the detection device 18 through the wires of the circuit board.
[0036] The multi-way valve 17 includes 5 inlets and 1 common port, which are the first inlet 171, the second inlet 172, the third inlet 173, the fourth inlet 174, and the fifth inlet 175; the common port is an outlet interface. The common port of the multi-way valve 17 is connected to the second sample inlet of the reaction cell 11 through a pipeline. By opening the circulation pump 14, the multi-way valve 15, the ion sensitive sensor 16 and one or several channels of the multi-way valve 17, the circulation and detection of the liquid in the ion sensitive sensor are realized.
[0037] The detection device 18 is composed of a circuit board and a program, which are respectively connected to the working electrode, the reference electrode and the auxiliary electrode for processing signals and calculating results.
[0038] The specific detection methods are as follows:
[0039] 1. After receiving the detection control signal, the instrument starts the cleaning process
[0040] The quantitative unit draws cleaning water into the reaction tank, the stirring device starts stirring to clean the reaction tank, the stirring device stops working, and the circulation pump passes the cleaning water in the reaction tank through multi-way valve 1, ion-sensitive sensor channel, and multi-way valve 2 to clean the entire device. The cleaning water returns to the reaction tank after cleaning, and the cleaning water is discharged into the waste liquid barrel through the drain valve by gravity.
[0041] 2. Detect the dissolution current baseline signal of the test solution
[0042] The quantitative unit extracts the test liquid of reagent one, reagent two or reagent three (reagent one, reagent two and reagent three are different electrolyte solutions, and usually three electrolyte solutions can test five kinds of heavy metal ions) into the reaction pool, and the stirring device mixes the liquid in the reaction pool. After mixing, the stirring device stops working, and the circulation pump is turned on. The circulation pump circulates the test liquid to the ion-sensitive sensor channel. After a certain period of enrichment by applying a constant voltage to the working electrode, a reverse voltage is applied to dissolve the heavy metal ions from the ion-sensitive membrane, and the detection unit detects the dissolution current baseline signal of the test liquid.
[0043] All the test liquid in the device is discharged into the waste liquid bucket through the reaction tank.
[0044] 4. Detect the dissolution current baseline signal of the standard solution
[0045] The precision sampler draws quantitative heavy metal standard solution into the reaction pool, and the stirring device mixes the liquid in the reaction pool. After mixing, the stirring device stops working and the circulation pump is turned on. The circulation pump circulates the standard solution to the ion-sensitive sensor channel. After a constant voltage is applied to the working electrode for enrichment for a certain period of time, a reverse voltage is applied to dissolve the heavy metal ions from the ion-sensitive membrane, and the detection unit detects the dissolution current signal of the standard solution.
[0046] 5. Obtain the concentration of heavy metal ions to be tested in the water sample
[0047] The detection device calculates the concentration of the heavy metal ions to be measured in the water sample according to the measured dissolution current baseline signal of the liquid to be measured and the dissolution current baseline signal of the standard solution.
[0048] Depending on the type of heavy metal to be measured, the above process is repeated until all heavy metal ions are measured.
[0049] The instrument performs the cleaning process again. The quantitative unit draws cleaning water into the reaction pool. The stirring device is turned on to clean the reaction pool. The stirring device stops working, the circulation pump is turned on, and all interfaces of multi-way valve 1 and multi-way valve 2 are opened. The cleaning water circulates to clean the channel of the ion-sensitive sensor to be tested. After cleaning with cleaning water, the drain valve is opened to discharge the cleaning water by gravity.
[0050] The process ends.
[0051] The solution of the present invention has the following advantages:
[0052] 1) The present invention adopts a multi-channel parallel detection method for detection, and different types of ion-sensitive sensors are used in each channel, so that multiple heavy metal ions can be detected simultaneously in a single detection.
[0053] 2) The present invention controls a multi-channel electromagnetic valve to detect different ions in different ion-sensitive sensor channels. Ion-sensitive membrane materials are configured in each channel to improve the selectivity for characteristic heavy metal ions. At the same time, different channels are not interconnected, which greatly reduces ion interference.
[0054] 3) The present invention is based on the traditional electrochemical method and combined with ion-sensitive sensors, which has low cost, simple principle and is suitable for online detection applications. The present invention can realize multi-channel parallel detection of different heavy metal ions, and the traditional electrochemical method is combined with a new ion-sensitive sensor to realize accurate online detection of multiple heavy metal ions.
Claims
1. Multi-channel water quality heavy metal ion detection device, Its characteristics are: include: Quantitative unit, multi-way valve, precision injector, reaction cell, circulation pump, multi-way valve 1, ion sensitive sensor, multi-way valve 2, detection device; The quantitative unit is provided with a liquid extraction port; The multi-way valve includes 9 independent interfaces, namely a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface, an eighth interface, and a ninth interface; The precision sample injector is provided with a sample inlet and a sample outlet; The liquid extraction port of the quantitative unit is connected to the first interface of the multi-way valve; The multi-way valve 2 includes 5 inlets and 1 common port; The multi-way valve 1 includes 5 inlets and 1 common port; The reaction pool is provided with three injection ports and one discharge port, and the three injection ports are respectively connected with the ninth interface of the multi-way valve, the sample outlet of the precision injector, the common port of the second multi-way valve and the inlet of the circulation pump; The circulation pump is provided with an inlet and an outlet, and the outlet of the circulation pump 14 is connected to the common port of the multi-way valve 15; The ion-sensitive sensor comprises: 5 channels, a working electrode, a reference electrode and an auxiliary electrode; the microchannel block has 5 micro chambers; the chamber is arranged in the middle of each channel, and the two ends of the chamber are provided with a lower inlet and an upper outlet of the channel; the lower inlet of each channel is connected to the outlet of the multi-way valve 1, and the upper outlet of the channel is connected to the inlet of the multi-way valve 2; The detection device is respectively connected with the working electrode, the reference electrode and the auxiliary electrode.
2. The multi-channel water quality heavy metal ion detection device according to claim 1, Its characteristics are: Also includes: Standard solution bottle; The standard solution bottle is connected to the precision sample injector.
3. The multi-channel water quality heavy metal ion detection device according to claim 1, Its characteristics are: A stirring device is arranged in the reaction tank.
4. The multi-channel water quality heavy metal ion detection device according to claim 1, Its characteristic is that include: Waste liquid barrel The waste liquid bucket is respectively connected to the eighth interface of the multi-way valve and the liquid discharge port of the reaction tank.
5. The multi-channel water quality heavy metal ion detection device according to claim 4, Its characteristics are: A drain valve is also provided on the communicating pipeline between the waste liquid barrel and the reaction tank.
6. The multi-channel water quality heavy metal ion detection device according to claim 1, Its characteristic is that include: Reagent bottle 1, reagent bottle 2, reagent bottle 3, cleaning bottle, water sample cup; The third interface of the multi-way valve is connected to the reagent bottle 1 through a pipeline; The fourth interface of the multi-way valve is connected to the second reagent bottle through a pipeline; The fifth interface of the multi-way valve is connected to the reagent bottle three through a pipeline; The sixth interface of the multi-way valve is connected to the cleaning bottle through a pipeline; The seventh interface of the multi-way valve is connected to the water sample cup through a pipeline.
7. The multi-channel water quality heavy metal ion detection device according to claim 1, Its characteristics are: The working electrode is provided with membranes of different heavy metal ions.
8. A detection method according to the multi-channel water quality heavy metal ion detection device according to any one of claims 1 to 7, Its characteristics are: The steps include: First, cleansing; The cleaning comprises: a quantitative unit draws cleaning water into a reaction pool, a stirring device starts stirring to clean the reaction pool, the stirring device stops working, a circulation pump passes the cleaning water in the reaction pool through a multi-way valve 1, an ion-sensitive sensor channel, and a multi-way valve 2, and the cleaning water is discharged into a waste liquid bucket through a drain valve; Second, detecting the dissolution current baseline signal of the test solution; The method for detecting the dissolution current baseline signal of the test liquid comprises: a quantitative unit extracts the test liquid of reagent one, reagent two or reagent three into a reaction pool, a stirring device mixes the liquid in the reaction pool, the stirring device stops working after mixing, a circulation pump circulates the test liquid to the ion-sensitive sensor channel, a working electrode applies a constant voltage to enrich for a certain period of time, and then applies a reverse voltage to dissolve the heavy metal ions from the ion-sensitive membrane, and a detection unit detects the dissolution current baseline signal; a dissolution current baseline signal of a third detection standard solution; The dissolution current baseline signal of the detection standard solution includes: a precision sampler extracts a quantitative heavy metal standard solution into a reaction pool, a stirring device mixes the liquid in the reaction pool, the stirring device stops working after mixing, a circulation pump is turned on, the circulation pump circulates the standard solution to the ion-sensitive sensor channel, a constant voltage is applied to the working electrode to enrich for a certain period of time, a reverse voltage is applied to the heavy metal ions to dissolve from the ion-sensitive membrane, and a detection unit detects the dissolution current signal of the standard solution; Fourth, the concentration of the heavy metal ion to be measured in the water sample is obtained according to the dissolution current baseline signal of the test solution and the dissolution current baseline signal of the standard solution.