TWI677472B - Detection method for heavy metal ions - Google Patents

Abstract

A method for detecting heavy metal ions is proposed, which includes the following steps. The wastewater is passed through an ion-imprinted polymer tube for adsorbing at least two kinds of target metal ions. Rinse the ion-imprinted polymer tube to remove non-targets from the ion-imprinted polymer tube. The target metal ions in the polymer tube are imprinted with acid desorption ions. The concentration of the target metal ion is detected electrochemically.

Description

Detection method of heavy metal ions

The invention relates to a method for detecting heavy metal ions, and to a method for detecting heavy metal ions in wastewater.

In recent years, due to the rapid development of industries such as electroplating, optoelectronics, printed circuit boards and semiconductor industries, the problem of heavy metal wastewater pollution has become increasingly serious. Heavy metal wastewater not only causes serious harm to the human body, but also destroys the environment in which humans live. Therefore, the detection method of heavy metal ions in wastewater becomes very important. However, there is a matrix in the untreated wastewater, which will cause the detected signal to shift and suppress, which will reduce the accuracy of the qualitative and quantitative detection results. Therefore, the wastewater must be treated before testing.

In general, the influence of the matrix is reduced by dilution or standard addition methods, but if the concentration of the target metal ion is very low, the detection result will be inaccurate. Another way is to modify the electrodes to reduce the potential shift. However, the price of modified electrodes is high, and different modified electrodes are required for different target metal ions, resulting in high cost and more processing steps.

The invention provides a method for detecting heavy metal ions, which can solve the problem of signal shift and suppression caused by the matrix of wastewater, so as to improve the accuracy of qualitative and quantitative detection results.

A method for detecting heavy metal ions of the present invention includes the following steps. The wastewater is passed through an ion-imprinted polymer tube for adsorbing at least two kinds of target metal ions. Rinse the ion-imprinted polymer tube to remove non-targets from the ion-imprinted polymer tube. The target metal ions in the polymer tube are imprinted with acid desorption ions. The concentration of the target metal ion is detected electrochemically.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings.

FIG. 1 is a flowchart of a method for detecting heavy metal ions according to an embodiment of the present invention. FIG. 2 is an operation schematic diagram of a method for detecting heavy metal ions according to an embodiment of the present invention.

Referring to FIG. 1 and FIG. 2 (a) at the same time, step S100 is performed to make the wastewater 100 flow through the ion-imprinted polymer tube 104 for adsorbing at least two kinds of target metal ions 102. The wastewater 100 includes a target metal ion 102 and a non-target object 103. In one embodiment, the target metal ion 102 includes a first target metal ion 102a and a second target metal ion 102b, but the present invention is not limited thereto. In another embodiment, the target metal ion 102 may also include three or more than three target metal ions.

The target metal ion 102 includes at least two of a lead ion, a copper ion, a chromium ion, a nickel ion, a zinc ion, and a cadmium ion. The target metal ion 102 may also be other metal ions commonly used in wastewater 100. The non-target object 103 is the matrix of the wastewater 100. The non-target object 103 includes non-target metal ions, organic substances, conductive impurities, interference substances, or a combination thereof, but the present invention is not limited thereto.

In one embodiment, the conductivity of the wastewater 100 is greater than or equal to about 2,000 microSiemens / cm. In more detail, the conductivity of the wastewater 100 is, for example, between about 2,000 micro-Siemens / cm to 3,000 micro-Siemens / cm. When stripping voltammetry is used to measure the concentration of metal ions in wastewater, its peak position and intensity will be severely affected by the conductivity value of the wastewater, causing signal shifts and deformations, which will cause qualitative and quantitative detection to be misjudged.

In one embodiment, the ion-imprinted polymer tube 104 has at least two kinds of ion-imprinted polymers 106 for adsorbing at least two kinds of target metal ions 102. In one embodiment, the ion-imprinted polymer 106 includes a first ion-imprinted polymer 106a and a second ion-imprinted polymer 106b. The first ion-imprinted polymer 106a and the second ion-imprinted polymer 106b are, for example, uniformly mixed with silica sand and then filled in the ion-imprinted polymer tube 104. In an embodiment, the ion-imprinted polymer tube 104 may also have three or more than three ion-imprinted polymers for adsorbing three or more target metal ions.

The manufacturing method of the ion-imprinted polymer 106 is as follows. First, a template molecule is provided, and then a functional group monomer is provided to generate a bond with the template molecule. Then, a cross-linking agent is added to perform a polymerization reaction to generate a polymer, and then the template molecule is removed from the polymer to obtain an ion-imprinted polymer 106 having a hole, and the surface of the hole has a functional group.

Because the pore structure of the ion-imprinted polymer 106 is the same as the structure of the template molecule to which it was originally bonded, the pores can capture the target metal ion 102 similar to the structure of the template molecule. After that, the ion-imprinted polymer 106 will bond with the target metal ion 102 captured by the hole to fix the target metal ion 102. Therefore, the ion-imprinted polymer 106 has a high selectivity in identifying a specific target and adsorbing the specific target, so different types of ion-imprinted polymers 106 can adsorb different kinds of target metal ions 102.

In an embodiment, the pores of the first ion-imprinted polymer 106a and the second ion-imprinted polymer 106b have different structures, so the first ion-imprinted polymer 106a and the second ion-imprinted polymer 106b will adsorb. Different kinds of target metal ions 102. In addition, since the structure of the pores of the ion-imprinted polymer 106 is different from the structure of the non-target object 103, the ion-imprinted polymer 106 does not adsorb the non-target object 103.

It is worth noting that different kinds of target metal ions 102 in the wastewater 100 are simultaneously adsorbed by the ion-imprinted polymer tube 104, and the target metal ions 102 are adsorbed in a single ion-imprinted polymer tube 104. Therefore, the present invention does not need to use more than one ion-imprinted polymer tube 104 to adsorb the target metal ions 102, thereby saving detection steps and costs.

Then, referring to FIG. 1 and FIG. 2 (b) simultaneously, step S200 is performed to rinse the ion-imprinted polymer tube 104 to remove the non-target object 103 in the ion-imprinted polymer tube 104. In more detail, there is a bond between the ion-imprinted polymer 106 and the target metal ion 102, so the target metal ion 102 is adsorbed by the ion-imprinted polymer 106 without being washed out of the ion-imprinted polymer tube 104. The non-target object 103 is not adsorbed by the ion-imprinted polymer 106, so when the ion-imprinted polymer tube 104 is rinsed, the non-target object 103 will flow out of the ion-imprinted polymer tube 104.

In one embodiment, the ion-imprinted polymer tube 104 is rinsed with deionized water 108, but the present invention is not limited thereto. In one embodiment, a buffer solution or an organic solution is used to rinse the ion-imprinted polymer tube 104. The buffer solution includes acetic acid / sodium acetate, hydrochloric acid, phosphoric acid boric acid mixed solution (Britton-Robinso), ammonium / ammonium chloride, phosphoric acid, the like, or a combination thereof, and the organic solvent may be methanol, ethanol, the like, or a combination thereof. In addition, as long as it is a liquid that has good fluidity and does not break the bond between the ion-imprinted polymer 106 and the target metal ion 102, it is suitable for flushing the ion-imprinted polymer tube 104.

Thereafter, referring to FIG. 1 and FIG. 2 (c) at the same time, step S300 is performed, and the target metal ion 102 in the polymer tube 104 is desorbed by the acid solution 110. In more detail, the acid solution 110 weakens the bond between the ion-imprinted polymer 106 and the target metal ion 102, so that the ion-imprinted polymer 106 cannot continue to adsorb the target metal ion 102. In addition, the smaller the acid-base value (pH value) of the acid solution 110 and the stronger the acidity, the better the effect of the acid solution 110 to weaken the bonding. The acid-base value of the acid solution 110 is, for example, less than or equal to 5, for example, between 0 and 5. The acid solution 110 includes sulfuric acid, hydrochloric acid, nitric acid, or a combination thereof, but the present invention is not limited thereto. The hydrochloric acid is, for example, hydrochloric acid having a pH of 2. In addition, other compounds that can be used to weaken the bond between the ion-imprinted polymer 106 and the target metal ion 102 are also suitable for the present invention.

In addition, after the target metal ion 102 is desorbed, the ion-imprinted polymer tube 104 can be dried, and can be used to adsorb the target metal ion 102 again, so as to achieve a cost-saving effect.

Next, referring to FIG. 1 and FIG. 2 (d) simultaneously, step S400 is performed to detect the concentration of the target metal ion 102 electrochemically. In detail, after the target metal ion 102 is desorbed by the acid liquid 110, the acid liquid 110 containing the target metal ion 102 is flowed to the detection container 112, as shown in FIG. 3. Then, the concentration of the target metal ion 102 is detected electrochemically. In one embodiment, the electrochemical method used is anodic stripping voltammetry (ASV). In addition, in special cases (such as moderate concentrations and qualitative), cyclic voltammetry can be used simply.

In one embodiment, the anode stripping voltammetry method uses a screen-printed tripolar electrode plate 114 to detect the concentration of the target metal ion 102. The schematic diagram of the device for the screen-printed tripolar electrode plate 114 is shown in FIG. 3 (a ). The screen printing tripolar electrode plate 114 has a small volume, and therefore has the advantage of being convenient to carry.

Next, referring to FIG. 3 (a), the screen-printed tripolar electrode plate 114 includes a working electrode 116, a counter electrode 118, and a reference electrode 120. The material of the working electrode 116 includes gold or bismuth. The material of the auxiliary electrode 118 includes gold, platinum, or carbon. The material of the reference electrode 120 includes silver chloride or silver. In addition, the screen-printed tripolar electrode plate 114 further includes a working electrode transmission portion 122 (electrically connected to the working electrode 116), an auxiliary electrode transmission portion 124 (electrically connected to the auxiliary electrode 118), and a reference electrode transmission portion 126 (electrical It is connected to the reference electrode 120) to output the measured signal to a signal analysis device (not shown) to make a potential-current diagram.

When using a screen-printed tripolar electrode plate 114 to detect the concentration of the target metal ion 102, the working electrode 116, the auxiliary electrode 118, and the reference electrode 120 are immersed in an acid solution 110 containing the target metal ion 102 to detect the target metal. The concentration of ions 102. When the material of the reference electrode 120 includes silver and the pH value of the acid solution 110 is less than 2, the acid solution 110 will severely corrode the reference electrode 120, causing the detection function of the screen-printed tripolar electrode plate 114 to fail.

Therefore, in order to prevent the acid solution 110 from seriously corroding the reference electrode 120 including silver, and also to effectively desorb the target metal ion 102, the preferred pH range of the acid solution 110 is between 2 and 5. In this way, the target metal ion 102 can be made to weaken the bond between the ion-imprinted polymer 106 and the target metal ion 102, and the operation of the reference electrode 120 can be maintained.

In another embodiment, the anodic stripping voltammetry method uses, for example, a tripolar electrode rod 128 to detect the concentration of the target metal ion 102. A schematic diagram of the device of the tripolar electrode rod 128 is shown in FIG. 3 (b). The tripolar electrode rod 128 has a working electrode 130, an auxiliary electrode 132, and a reference electrode 134. The material of the working electrode 130 includes gold or bismuth. The material of the auxiliary electrode 132 includes gold or carbon. The material of the reference electrode 134 includes silver chloride or silver.

When the tri-electrode electrode rod 128 is used to detect the concentration of the target metal ion 102, the working electrode 130, the auxiliary electrode 132, and the reference electrode 134 are immersed in the acid solution 110 containing the target metal ion 102 to detect the concentration of the target metal ion 102. To make a potential-current diagram.

It is worth noting that most of the surfaces of the auxiliary electrode 132 and the reference electrode 134 of the tripolar electrode rod 128 are covered with glass 136. Therefore, when the material of the reference electrode 134 includes silver, the glass 136 can protect most of the reference electrode 134 from being corroded by the acid solution 110. Therefore, rather than using a screen-printed tripolar electrode plate 114, an acid solution 110 having a stronger acidity can be selected to achieve a more effective desorption of the target metal ion 102 without damaging the reference electrode 134. The pH of the acid solution 110 is, for example, between 0 and 5.

Conventional methods for detecting heavy metal ions use electrode modification to reduce the effect of non-targets 103 on the detection results, but electrode modification has the disadvantage of high cost. Compared with the conventional electrode modification method for detection, the method for detecting heavy metal ions of the present invention can directly use the working electrode 116/130, auxiliary electrode 118/132, and reference electrode 120/134 without electrode modification to target The concentration of the metal ions 102 is detected, thereby achieving a cost-saving effect.

In addition, in the method of the present invention, before the concentration of the target metal ion is detected by the electrochemical method, the interference matrix of the wastewater has been completely replaced with the acid solution 110. In this way, interference can be effectively reduced, the oxidation potential of the target metal ion can be kept consistent with the pure water system, and false judgments can be effectively reduced. In addition, the invention can replace the substrate in any raw water with an acid solution with a fixed concentration, which can effectively extend the service life of the electrode.

In addition, in the method of the present invention, before the concentration of the target metal ion 102 is detected by an electrochemical method, the non-target object 103 that would interfere with the detection has been removed, so that the non-target object can be avoided when the concentration of the target object is detected. Interference in order to obtain more accurate detection results. More specifically, since the problem that the non-target object 103 interferes with the detection result has been improved, by detecting the low-concentration target metal ion 102 through the method of the present invention, a low-intensity signal that is originally suppressed can be detected. The detection method of the present invention can detect that the concentration of the target metal ion 102 is, for example, 15 ppm, 10 ppm, 5 ppm, or 2 ppm.

Furthermore, after the target metal ion 102 in the ion-imprinted polymer tube 104 is desorbed by the acid solution 110 of the present invention, the target metal ion 102 can be detected immediately without reprocessing the target metal ion 102. In this way, the effect of saving detection steps can be achieved.

In the following, a plurality of experimental examples and comparative examples are provided to explain the effects of the above embodiments, but the scope of the present invention is not limited to the following.

＜ Experimental Example 1 ＞

Wastewater is provided with a pH of approximately 6 and a conductivity of approximately 2,000 microSiemens / cm. Next, 2 ppm of copper ions were added to the wastewater. After that, the wastewater is passed through an ion-imprinted polymer tube having a copper-ion imprinted polymer to adsorb copper ions.

The detailed preparation method of copper ion imprinted polymer is as follows. 4 mmole of 4-vinyl pyridine (as a functional monomer) and 0.5 mmole of copper nitrate (Cu (NO ₃ ) ₂ ) (as a template) Ion) was added to 35 ml of acetonitrile and stirred overnight. Another 20 mmole of ethylene glycol dimethacrylate (EGDMA) (as a cross-linking agent) was added to the solution, and the solution was passed into N _{2 to} remove O ₂ from the solution. The solution was placed in a 65 ° C oil bath, and then Add 100 mg of azobisisobutyronitrile (AIBN) (as a starter) to the solution and stir for 24 hours. After the reaction is completed, the generated powder is washed several times with methanol / water with a volume ratio of 1: 4 to remove unreacted materials, and then the powder is washed several times with 0.5M HCl to remove the Cu in the powder. ^{2+ is} removed, and finally the powder is washed with deionized water until the powder becomes neutral, and the powder is dried in an oven. After grinding, a copper ion imprinted polymer can be obtained.

Next, the ion-imprinted polymer tube is rinsed with deionized water to remove the matrix. Then, copper ion was desorbed using hydrochloric acid having a pH of about 2. Finally, anodic stripping voltammetry was performed on hydrochloric acid with copper ions using a screen-printed tripolar electrode plate. The results are shown in curve 1 in FIG. 4.

〈Comparative example 1〉

The same wastewater as in Experimental Example 1 was provided. Next, 2 ppm of copper ions were added to the wastewater. After that, the screen printing tripolar electrode plate was directly used to perform anodic stripping voltammetry on the wastewater, and the result is shown in curve 2 in FIG. 4.

〈Comparative example 2〉

Provide deionized water. Add 2 ppm of copper ions to deionized water. After that, the screen printing tripolar electrode plate was directly used for anodic stripping voltammetry detection of deionized water, and the result is shown in curve 3 in FIG. 4.

Comparing curve 1, curve 2 and curve 3 in FIG. 4, it can be seen that the potential and current signals detected by Experimental Example 1 are very close to the detection results of Comparative Example 2. In contrast, the potential and current signals detected by Comparative Example 1 are compared with The detection result of Comparative Example 2 is greatly shifted. This shows that through the method for detecting heavy metal ions of the present invention, a more accurate quantitative and qualitative analysis can be obtained.

In addition, the copper ion concentrations measured in Experimental Example 1, Comparative Example 1, and Comparative Example 2 are recorded in Table 1. In addition, the anode stripping voltammetry of Experimental Example 1, Comparative Example 1, and Comparative Example 2 was changed to use atomic absorption spectroscopy (AAS) to detect the concentration of copper ions with an atomic absorption spectrometer. The results were Also recorded in Table 1.

Table 1

According to Table 1, it can be seen that in Experimental Example 1, the copper ion concentration measured by the anodic stripping voltammetry after the adsorption, rinsing, and desorption treatments of the present invention is compared with the anodic stripping of volts directly in Comparative Example 1. The concentration measured by Anfa for untreated wastewater containing 2 ppm copper ions is closer to the actual concentration of copper ions. In addition, Comparative Example 1 has a larger error value than Experimental Example 1. It can be seen that the method for detecting heavy metal ions according to the present invention can improve the signal shift and suppression caused by the matrix, and can improve the qualitative and quantitative detection results. Accuracy.

＜ Experimental Example 2 ＞

Wastewater is provided with a pH of approximately 6 and a conductivity of approximately 2,000 microSiemens / cm. Next, 2 ppm of lead ions were added to the wastewater. After that, the wastewater is passed through an ion-imprinted polymer tube having a lead-ion imprinted polymer to adsorb lead ions.

The detailed preparation method of lead ion imprinted polymer is as follows. 0.89 g of 1-vinylimidazole and 0.0828 g of lead nitrate Pb (NO ₃ ) _{2 are} added to 5 ml of tetrahydrofuran (Tetrahydrofuran, THF) and stirred for 30 minutes. Then, 0.13 g of 3- (trimethoxysilyl) propylmethacrylate (TMSPMA) and 2 ml of tetrahydrofuran were added to the solution, and the solution was passed into N _{2 to} remove O in the solution. _2. Place the solution in a 68 ° C oil bath, add 1.6 mg of AIBN, and stir the solution for 16 hours. After the reaction is completed, the generated powder is washed several times with 2M nitric acid to remove the Pb ²⁺ in the powder, and finally washed with deionized water until the powder is neutral, and the powder is dried in an oven. dry. After grinding, the product can be obtained.

Next, the ion-imprinted polymer tube is rinsed with deionized water to remove the matrix. Then, hydrochloric acid having a pH of about 2 was used to desorb the lead ions. Finally, anodic stripping voltammetry was performed on the hydrochloric acid with lead ions using a screen-printed tripolar electrode plate.

〈Comparative example 3〉

The same wastewater as in Experimental Example 2 was provided. Next, 2 ppm of lead ions were added to the wastewater. After that, the screen printing tripolar electrode plate was directly used for anodic stripping voltammetry detection of wastewater.

〈Comparative example 4〉

Provide deionized water. Add 2 ppm of lead ions to deionized water. After that, the screen printing tripolar electrode plate was directly used for anodic stripping voltammetry detection of deionized water.

In addition, the concentrations of lead ions measured in Experimental Example 2, Comparative Example 3, and Comparative Example 4 are recorded in Table 2. The anode stripping voltammetry of Experimental Example 2, Comparative Example 3, and Comparative Example 4 was changed to use atomic absorption spectroscopy (AAS) to detect the concentration of lead ions by atomic absorption spectrometry. The results were also Recorded in Table 2.

Table 2

According to Table 2, it can be seen that in Experimental Example 2, the actual concentration close to the lead ions can be measured using the anode stripping voltammetry after the adsorption, washing and desorption treatments of the present invention. In contrast, the lead ion concentration in Comparative Example 3 could not be measured at all. It can be known that the method for detecting heavy metal ions of the present invention can improve signal shift and suppression caused by a matrix, and can improve the accuracy of qualitative and quantitative detection results.

＜ Experimental Example 3 ＞

Copper ion imprinted polymer (manufacturing method is the same as Experimental Example 1), lead ion imprinted polymer (manufacturing method is the same as Experimental Example 2) and silica sand (trade name: Aldrich 806765, particle size 3 μm, purchased from Sigma Aldrich ) Mix evenly. It is then filled in an ion-imprinted polymer tube. Next, a simulated wastewater having a conductivity of about 2,400 micro Siemens / cm was provided, and 10 ppm of copper ions and 10 ppm of lead ions were added to the simulated wastewater.

Then, the simulated wastewater is passed through an ion-imprinted polymer tube having a copper ion-imprinted polymer and a lead-ion imprinted polymer to adsorb copper ions and lead ions. Next, the ion-imprinted polymer tube is rinsed with deionized water to remove the matrix. Then, copper ion and lead ion were desorbed using hydrochloric acid having a pH of about 2. Finally, a screen-printed tripolar electrode plate was used for anodic stripping voltammetry detection, and the result is shown in curve 4 in FIG. 5.

〈Comparative example 5〉

The same simulated wastewater as in Experimental Example 3 was provided. Next, 10 ppm of copper ions and 10 ppm of lead ions were added to the simulated wastewater. After that, the screen printing tripolar electrode plate was directly used to perform anodic stripping voltammetry on the waste water, and the result is shown in curve 5 in FIG. 5.

〈Comparative example 6〉

Add 10 ppm of copper ions and 10 ppm of lead ions to deionized water. After that, the screen-printed tripolar electrode plate was directly used to perform anodic stripping voltammetry detection on the deionized water, and the result is shown in curve 6 in FIG. 5.

According to FIG. 5, compared with Comparative Example 6, it can be seen that the potential and current signals of the simulated wastewater without the adsorption, flushing, and desorption treatments of Comparative Example 5 are much shifted. The current signal of lead ions (the left half of FIG. 5) ) Even completely suppressed. In contrast, experimental example 3 has a detection result close to that of comparative example 6. Therefore, it is shown that by using the method for detecting heavy metal ions of the present invention, the matrix in the wastewater has been replaced with hydrochloric acid, which can effectively solve the problem that the anode stripping voltammetry is easily affected by matrix interference The problem of reducing the accuracy of the quantitative and qualitative analysis of the target metal ion.

In addition, FIG. 5 also shows obvious signals of copper ions and lead ions, so it also illustrates that the detection method of the present invention can simultaneously perform the adsorption, washing and desorption treatment of two target metal ions in the wastewater to be detected , And then quantitative and qualitative analysis of the two target metal ions. Based on the above, the method for detecting heavy metal ions of the present invention can effectively reduce the problem of signal shift and suppression caused by substrates in wastewater, and can improve the accuracy of qualitative and quantitative detection results. In addition, the detection method of the present invention can effectively detect a target metal ion at a low concentration.

In addition, the detection method of the present invention does not require electrode modification, and multiple target metal ions in wastewater can be sequentially adsorbed, washed, and desorbed in a single ion-imprinted polymer tube at the same time, and then the concentration of the target metal ions is directly detected. Therefore, the effect of saving detection steps and costs can be achieved.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

S100, S200, S300, S400 ‧‧‧ steps

100‧‧‧ wastewater

102‧‧‧ target metal ion

103‧‧‧ non-target

104‧‧‧Ion Overprint Polymer Tube

106‧‧‧Ion Overprint Polymer

106a‧‧‧The first ion-imprinted polymer

106b‧‧‧Second ion-imprinted polymer

108‧‧‧ deionized water

110‧‧‧acid solution

112‧‧‧test container

114‧‧‧Screen printing tripolar electrode plate

116, 130‧‧‧ working electrode

118, 132‧‧‧Auxiliary electrode

120, 134‧‧‧Reference electrode

122‧‧‧Working electrode transmission department

124‧‧‧Auxiliary electrode transmission section

126‧‧‧Reference electrode transmission section

128‧‧‧Tripolar electrode rod

136‧‧‧ Glass

FIG. 1 is a flowchart of a method for detecting heavy metal ions according to an embodiment of the present invention. FIG. 2 is an operation schematic diagram of a method for detecting heavy metal ions according to an embodiment of the present invention. 3 is a schematic diagram of a screen printing tripolar electrode plate and a tripolar electrode rod device used in an embodiment of the present invention. FIG. 4 is a potential-current diagram of Experimental Example 1, Comparative Example 1, and Comparative Example 2 of the present invention. 5 is a potential-current diagram of Experimental Example 2, Comparative Example 3, and Comparative Example 4 of the present invention.

Claims (10)

A method for detecting heavy metal ions, comprising: flowing waste water through an ion-imprinted polymer tube for adsorbing at least two kinds of target metal ions; washing the ion-imprinted polymer tube to remove the ion-imprinted polymer A non-target substance in a tube; the target metal ion in the ion-imprinted polymer tube is desorbed with an acid solution, wherein the target metal ion includes lead ion, copper ion, chromium ion, nickel ion, zinc ion, and At least two of cadmium ions; and the concentration of the target metal ion is detected electrochemically. The method for detecting heavy metal ions according to item 1 of the scope of the patent application, wherein the at least two target metal ions in the wastewater are simultaneously adsorbed by the ion-imprinted polymer tube. The method for detecting heavy metal ions according to item 1 of the scope of patent application, wherein the ion-imprinted polymer tube has at least two types of ion-imprinted polymers. The method for detecting heavy metal ions according to item 1 of the scope of patent application, wherein the conductivity of the wastewater is greater than or equal to 2,000 microSiemens / cm. The method for detecting heavy metal ions according to item 1 of the scope of patent application, wherein the ion-imprinted polymer tube is rinsed with deionized water. The method for detecting a heavy metal ion according to item 1 of the scope of the patent application, wherein the acid solution includes sulfuric acid, hydrochloric acid, nitric acid, or a combination thereof. The method for detecting heavy metal ions according to item 6 of the scope of the patent application, wherein the acid-base value of the acid solution is between 0 and 5. The method for detecting heavy metal ions according to item 1 of the scope of the patent application, wherein the electrochemical method includes detecting a concentration of the target metal ion using a tripolar electrode rod or a screen-printed tripolar electrode plate. The method for detecting heavy metal ions according to item 1 of the scope of patent application, wherein after the target metal ions in the ion-imprinted polymer tube are desorbed with the acid solution, the electrochemical detection method is used directly. The concentration of the target metal ion. The method for detecting heavy metal ions according to item 1 of the scope of the patent application, wherein the electrochemical method includes an anode stripping voltammetry or a cyclic voltammetry.