99 results about "Cadmium ion" patented technology

The invention discloses a fluorescent / colorimetric dual-mode paper-based sensor for detecting cadmium ions in rhizoma polygonati as well as a preparation method and application of the fluorescent / colorimetric dual-mode paper-based sensor, and belongs to the technical field of detection of heavy metal residues in food with homology of medicine and food. PEI-UCNPs and PtNPs are loaded on a paper base and are mixed and reacted with Apt-AMNPs (at) TMB, H2O2, a PBS buffer solution and a solution containing Cd < 2 + >. The Aptamer specifically recognizes and captures Cd < 2 + >, so that the Apt-AMNPs (at) TMB is dissociated, and the TMB is released from holes of the AMNPs; the PtNPs on the paper base catalyzes colorless TMB (Tetramethylbenzidine) to generate blue oxide (oxTMB) under the action of H2O2, and the oxTMB can quench up-conversion fluorescence of PEI-UCNPs through fluorescence inner filtration. When the fluorescence / colorimetric dual-mode paper-based sensor is used for detecting the content of cadmium ions in rhizoma polygonati, the fluorescence / colorimetric dual-mode paper-based sensor has the characteristics of simplicity and convenience in operation, low detection cost, rapidness, specificity, sensitivity, portability and the like, and the fluorescence / colorimetric dual-mode paper-based sensor can be applied to on-site detection of the cadmium ions in rhizoma polygonati.

The invention discloses a cadmium ion and lead ion detection system and method based on CRISPR and deoxyribozyme, and the method comprises the following steps: forming active deoxyribozyme by using target ions and a recognition probe, cutting a redundant sequence in a substrate probe, releasing a semi-activator, and cooperatively activating the activity of CRISPR-Cas12a with the other semi-activator in the system. According to the system, the signal-to-noise ratio and the sensitivity of detection are improved by utilizing the effect of inhibiting cooperative activation by redundant fragments in semi-activators. According to the detection method, nano material modification on the substrate probe is not needed, magnetic separation is not needed, and the detection cost is reduced. The detection process only needs two steps of room temperature incubation reaction, and the two steps are carried out in one reaction tube, so that cross contamination possibly caused by multi-tube reaction is avoided, and the detection process is simplified. The method can be applied to detection of cadmium ions and lead ions in rice or serum samples, and has wide application prospects in the fields of food safety, medical detection and the like.

The invention relates to the technical field of semiconductor luminescent materials, in particular to a wide-band-gap semiconductor crystal luminescent material and a preparation method and application thereof. The chemical composition of the CdLCl < 2 >. H2O or the Cd2L2 (Ac) (H2O) is [CdLCl] < 2 >. H2O]. L represents a quinoline carboxylic acid ligand; ac represents an acetate ion; the crystal structure of the wide-band-gap semiconductor crystal luminescent material is a one-dimensional chain structure. The crystal complex is mainly formed by bridging cadmium ions with carboxyl of a quinoline carboxylic ligand, and the formed crystal complex emits light in a red region, is suitable for various light-emitting application scenes, and solves the problems that an existing wide-band-gap semiconductor light-emitting material is relatively low in light-emitting efficiency, light stability and heat stability, and the light-emitting efficiency is low. And the light-emitting wavelength is difficult to regulate and control.

A kind of water environment cadmium ion and temperature double parameter optical fiber chemical sensing system relates to water body environment detection field.In the above system, spontaneous emission light source is near infrared light source;The surface of optical fiber sensing unit is coated with magnetic MOF-cadmium ion imprinted polymer;The light signal generated by spontaneous emission light source enters optical fiber sensing unit, optical spectrometer collects the transmission spectrum signal of optical fiber sensing unit, and the collected spectrum data are output to photoelectric detection module;Photoelectric detection module converts light signal into electrical signal and transmits to demodulation module;Demodulation module gives the cadmium ion concentration and temperature according to input signal using machine learning algorithm.The present application has higher specific recognition ability to cadmium ion, and can effectively separate the coupling influence of cadmium ion concentration and temperature on sensing signal.

A ZIF-derived zinc-cadmium sulfide photocatalyst, its preparation method, and its application are disclosed. The catalyst, by molar fraction, comprises: 35-50% 2-methylimidazole; 0-7.7% divalent cadmium ion compound; 0-7.7% divalent zinc ion compound; 7-10% thioacetamide; and 35-50% amines. The preparation method involves: preparing a 2-methylimidazole solution and a cadmium-zinc mixed solution separately; then preparing a ZIF precursor solution with cadmium and zinc as the central metals; adding thioacetamide to the precursor solution; transferring the solution to a polytetrafluoroethylene liner and hydrothermally treating it; finally collecting the hydrothermally treated solution, centrifuging, washing, drying, and grinding to obtain the ZIF-derived zinc-cadmium sulfide photocatalyst. The catalyst prepared by this invention has a large specific surface area and exhibits significant catalytic effects in photocatalytic water splitting for hydrogen production. Furthermore, the catalyst has a stable structure and can be recycled for a long period without a significant decrease in the hydrogen production rate.

The application discloses a high-strength steel unqualified zinc-cadmium alloy plating layer stripping method, and its stripping process is as follows: 80-150 g / L of sodium nitrite, 50-100 g / L of ammonium bicarbonate, 50-100 g / L of ammonium chloride, the pH of the stripping solution is 6-8, and normal temperature operation is adopted. The sodium nitrite is used as an oxidizing agent and a steel base inhibitor for the zinc-cadmium alloy plating layer, the ammonium bicarbonate is used as a complexing agent for zinc ions and cadmium ions and a pH buffer for the plating solution, and the ammonium chloride is used as a complexing agent for zinc ions and cadmium ions and a promoter for dissolving the zinc-cadmium alloy plating layer. When the pH of the stripping solution is too high, dilute nitric acid is used to reduce the pH, and when the pH is too low, sodium carbonate solution is used to increase the pH. The technical scheme of the application is used to replace the chromium acid stripping method, and the high pollution problem caused by the use of the chromium acid is overcome.

The invention provides an algae source soil conditioner for synergistically passivating copper and cadmium as well as a preparation method and application of the algae source soil conditioner, and belongs to the technical field of soil remediation. The algae source soil conditioner comprises an algae source active component and a biochar-based carrier. By combining activity retention of the seaweed extract and functional modification of pyrolytic carbon, the content of copper ions and cadmium ions in soil can be remarkably reduced, meanwhile, the activity of soil urease, sucrase and dehydrogenase is promoted to be remarkably improved, and the synergistic effect of heavy metal passivation and soil ecological function restoration is achieved; the preparation method disclosed by the invention is simple and easy to operate, and the prepared algae source soil conditioner has a multi-stage pore structure and rich surface functional groups.

The invention provides an aqueous cadmium ion-vanadium dioxide battery as well as a preparation method and application thereof, and relates to the field of ocean energy storage. The battery comprises a negative electrode, a positive electrode, a diaphragm and an aqueous electrolyte, the negative electrode is metal cadmium or cadmium-based alloy; the active material of the positive electrode is metastable monoclinic phase vanadium dioxide; the diaphragm is a glass fiber diaphragm; the aqueous electrolyte is an aqueous solution containing cadmium salt; the total concentration of the cadmium salt in the aqueous electrolyte is 1-4 mol / L. The aqueous vanadium dioxide-cadmium metal secondary battery disclosed by the invention has the advantages of safe aqueous electrolyte system, high rate capability, ultra-long cycle life and the like, and has remarkable advantages when being applied to ocean energy storage.

The invention discloses an electroplating disqualified cadmium layer stripping solution, a preparation method and a use method, and the electroplating disqualified cadmium layer stripping solution comprises 6-8 parts of sodium phytate, 1-3 parts of sodium nitrilotriacetate, 2-4 parts of borate, 5-10 parts of sodium bromate, 1-2 parts of sodium alkyl naphthalene sulfonate, 1-2 parts of glucoside, 5-8 parts of sodium nitrate, 3-5 parts of ammonia water, 2-4 parts of triol ethylamine, 4-6 parts of 1-hydroxyethylidene-1, 1-diphosphonic acid and 8-12 parts of ammonium persulfate. The total amount of the purified water is 100 parts, and the total amount of the purified water is 100 parts. The pH value of the deplating agent solution is alkaline, the problem of hydrogen evolution of a hydrogen sensitive material is solved, the risk of hydrogen embrittlement is avoided, and hydrogen removal is not needed after steel and iron materials are deplated; cadmium ion heavy metal pollution and sewage treatment difficulty exist, the stripped cadmium ions automatically generate precipitates, recycling is facilitated, and the sewage treatment difficulty is reduced; the metal deplating liquid is convenient to use and simple to operate, only unqualified products need to be put into the deplating liquid in a room-temperature environment, after a certain time, after a plating layer is completely removed, the unqualified products are washed with water, and a metal base material is not damaged.

The invention discloses application of an NtbHLH128 transcription factor in improving heavy metal cadmium resistance of plants, and belongs to the technical field of gene engineering. According to the invention, an NtbHLH128 gene knockout mutant plant is constructed through a gene editing technology, and the knockout mutant plant can maintain normal growth in a heavy metal cadmium polluted environment and shows remarkable cadmium stress resistance; meanwhile, the knockout mutant plant also has high enrichment capacity, cadmium ions in the environment can be enriched, and the heavy metal concentration in the environment is reduced. The regulation effect of the NtbHLH128 gene in heavy metal stress is defined, an important target gene is provided for cultivating new varieties of crops which are highly resistant to heavy metal stress and used for contaminated soil remediation, a theoretical basis is laid for ecological remediation work, and the NtbHLH128 gene has important application value.

The invention discloses a device and a method for treating heavy metal wastewater through electrochemical adsorption. The method comprises a working electrode, a counter electrode, an insulation isolation part, a fixed frame and a direct-current power supply, the working electrode is formed by coating a graphite paper substrate with a composite electrode material containing titanium dioxide (TiO2), ferroferric oxide (Fe3O4), conductive carbon black and polyvinylidene fluoride (PVDF); the counter electrode is made of pure graphite paper and is parallel to the working electrode; the insulating isolation part is arranged between the working electrode and the counter electrode; the fixed frame is used for fixing the working electrode, the counter electrode and the insulated isolation component; the direct-current power supply is connected with the working electrode and the counter electrode. The device is formed by arranging a composite electrode and a graphite paper counter electrode in parallel, isolating by a polytetrafluoroethylene gasket, fixing by an acrylic plate and externally connecting a direct-current power supply. The electrode adsorbs Cd < + > in electrolyte-containing wastewater. By combining the high adsorbability of TiO2, the magnetic recovery characteristic of Fe3O4 and a conductive network, the method has the advantages of high efficiency, stability and easiness in recovery.

The invention belongs to the technical field of photocatalysts, and particularly relates to a twin-crystal zinc cadmium sulfide nanosheet, a composite photocatalyst and a preparation method and application thereof.The preparation method of the twin-crystal zinc cadmium sulfide nanosheet comprises the following steps that a zinc source, a diethylenetriamine aqueous solution and a sulfur source are mixed, a first solvothermal reaction is conducted, and a second solvothermal reaction is conducted; a zinc sulfide-diethylenetriamine composite precursor is obtained; mixing the zinc sulfide-diethylenetriamine composite precursor, a cadmium source and an organic solvent, and performing a second solvothermal reaction to replace part of zinc ions in crystal lattices of the zinc sulfide-diethylenetriamine composite precursor with cadmium ions to obtain a zinc cadmium sulfide-diethylenetriamine composite precursor; and dispersing the zinc cadmium sulfide-diethylenetriamine composite precursor in water, and carrying out hydrothermal reaction to remove diethylenetriamine molecules, thereby obtaining the twin crystal zinc cadmium sulfide nanosheet. The twin crystal interface can provide a preferential carrier migration channel, so that photo-induced electron-hole separation is further promoted, and the photocatalytic hydrogen production performance is improved.

The invention discloses a cadmium telluride thin film battery cadmium chloride spraying monitoring and control system and method. The system comprises a material preparation module used for preparing and storing a cadmium chloride solution containing a cadmium ion fluorescent probe; the spraying module is used for uniformly spraying the solution containing the probe to the surface of the cadmium telluride substrate to form a liquid film; the on-line detection module is used for collecting a liquid film fluorescence image through an optical detection unit and measuring the conductivity of the liquid film in a non-contact manner through a conductivity detection unit; and the data processing and control module is used for carrying out fusion analysis on the fluorescence image and the conductivity data, calculating the coverage rate, the uniformity and the cadmium chloride content of the liquid film in real time, and dynamically adjusting spraying parameters and probe injection parameters according to an analysis result, so as to realize closed-loop accurate control of the coating process. The problems that in the prior art, real-time performance is poor, blind areas exist in microcosmic distribution detection, and control precision is insufficient are effectively solved, and the consistency of the coating technology and the material utilization rate are improved.

The application relates to the technical field of adsorbents, and discloses a cadmium ion selective adsorbent and a preparation method thereof, which is prepared from the following raw materials in parts by weight: 2-3 parts of aminoundecanoic acid, 2-3 parts of citric acid, 0.45-0.6 parts of NaOH, 4-6 parts of cellulose, 4-6 parts of thiocyanogen, 4-6 parts of nano silicon dioxide, 450-650 parts of MES buffer solution, 500 parts of PBS buffer solution, 8-12 parts of a coupling agent, 8-12 parts of a crosslinking agent, 0.4-0.6 parts of metallothionein and 20-30 parts of water. The application bonds the metallothionein and the carbon dot surface carboxyl through an amide reaction, and combines the modified cellulose through a large number of hydrogen bonds, so that the combination capacity of the two is greatly enhanced, and the stability of the adsorbent is improved. The prepared adsorbent has excellent selective adsorption for cadmium, excellent tolerance for some common coexisting interfering ions in water bodies, and excellent industrial application prospect.

This scheme discloses a method for adsorbing cadmium ions in the field of heavy metal adsorption technology, specifically: using acylhydrazone-sodium alginate-Ca 2+ Composite adsorbent for heavy metal Cd 2+ Adsorption occurs, wherein the acylhydrazone-sodium alginate-Ca 2+ The composite adsorbent is prepared by reacting salicylhydrazine with sodium hydroxide after alkalization and oxidation with sodium periodate to form a salicylhydrazone compound, which is then cross-linked with sodium alginate. The method described in this application can simultaneously reduce the amount of distiller's grains and the heavy metal Cd. 2+ Pollution.

The invention relates to a method for accurately adding a cadmium removal agent on line in wet-process phosphoric acid production, which comprises the following steps: eliminating complex matrix interference through pretreatment of filtration, dilution and pH regulation, quickly detecting by using a portable heavy metal detector provided with a cadmium ion selective electrode, and realizing real-time concentration calculation in combination with a standard curve; and performing medicament increase and decrease amount calculation on a detection result and a preset target range, and dynamically adjusting the adding amount of the cadmium removal medicament according to a preset target concentration range and a medicament dosage coefficient to realize accurate control. The method solves the problems that a traditional detection method cannot quickly respond on site, the waste of a cadmium removal agent is serious or the cadmium removal effect is poor, and the cadmium removal treatment cost of per ton of phosphoric acid is greatly reduced.

The present invention belongs to the technical field of fluorescent active material development, and particularly relates to a cadmium (II)-based metal organic framework crystalline material, its preparation method, and application. The molecular formula of the cadmium (II)-based metal organic framework crystalline material is {[Cd3(Br-BDC)3(BMIP)2]·2H2O} n， The three-dimensional structure is formed using cadmium (II) ions as connecting nodes, BMIP and H2 (Br-BDC) ligands as bridging ligands. The structure contains Cd-O secondary structural units, with three Cd atoms forming a trinuclear Cd-O cluster structure through the Cd-O secondary structural units. The Cd1 and Cd1# atoms exhibit mirror-image symmetry. The present invention utilizes a one-pot solvothermal reaction to prepare a divalent cadmium ion fluorescent sensing material. This preparation method has the advantages of a simple process, easy operation, high yield, and good reproducibility. The cadmium (II) fluorescent sensing material exhibits a strong fluorescence emission spectrum and can be applied in molecular fluorescent probes, metal ion detection, and other fields.

The invention belongs to the technical field of soluble zinc determination, and particularly relates to a method for determining the content of soluble zinc in a raw material for producing electrolytic zinc by a chlorine-ammonia method. The method comprises the following steps: firstly, carrying out ammoniacal leaching on raw materials for producing electrolytic zinc by using a chloramine method, then carrying out primary precipitation and impurity removal on metal impurity elements in a dissolved leaching solution by using a chemical precipitation method, and further eliminating the influence of unremoved metal impurity ions such as lead ions, cadmium ions, iron ions, copper ions and aluminum ions by using a masking agent. The accuracy of the determination result is improved, the soluble zinc content of the raw material is truly reflected, and the industrial production is better guided.

The application provides a fluorescent probe for detecting cadmium ions and application thereof in detecting cadmium ions. The structural formula of the fluorescent probe is shown in formula 1, formula 2, formula 3 or formula 4. The fluorescent probe molecule has the advantages of high sensitivity for detecting Cd2+, instantaneous response and fluorescence visualization.

The invention relates to the technical field of adsorbents, and discloses a preparation method of a cadmium ion selective adsorbent. The invention relates to a water-based metal corrosion inhibitor which comprises the following components in parts by weight: 2-3 parts of amino undecanoic acid, 2-3 parts of citric acid, 0.45-0.6 part of NaOH, 4-6 parts of cellulose, 4-6 parts of thiourea, 4-6 parts of nano silicon dioxide, 450-650 parts of an MES buffer solution, 500 parts of a PBS buffer solution, 8-12 parts of a coupling agent, 8-12 parts of a cross-linking agent, 0.4-0.6 part of metallothionein and 20-30 parts of water. Metallothionein is bonded with carboxyl on the surfaces of the carbon dots through an amide reaction and is bonded with modified cellulose through a large number of hydrogen bonds, the bonding capacity of the metallothionein and the modified cellulose is greatly enhanced, and the stability of the adsorbent is improved. The adsorbent prepared by the invention has excellent selective adsorption to cadmium, has excellent tolerance to some common coexisting interfering ions in a water body, and has excellent industrial application prospects.

The invention relates to a sulfydryl silicon dioxide coated magnetic biochar material, a preparation method thereof and an application of the sulfydryl silicon dioxide coated magnetic biochar material in adsorbing and removing cadmium ions, the material takes biochar prepared from aquaculture byproducts as a substrate, and Fe3O4 magnetic particles, a silicon dioxide coating layer and a sulfydryl functional group are loaded in sequence. The method comprises the following steps: firstly, synthesizing magnetic biochar containing SiO2-coated Fe3O4 particles on the surface by a coprecipitation method under an alkaline condition, and then carrying out sulfydryl modification on the magnetic biochar by a grafting method to finally prepare the sulfydryl-modified silicon dioxide-coated magnetic biochar adsorbent. The adsorbent prepared by the method has the characteristics of high specific surface area, abundant pore structures, a large number of sulfydryl active groups and the like, shows high adsorption capacity and good selectivity on cadmium ions in water, and can be conveniently separated and recycled through magnetism. The material can also be used for adsorbing lead, copper, zinc, chromium and other heavy metal ions, the preparation process is simple, and the material has wide application prospects in the field of heavy metal wastewater treatment.

The application discloses a method for improving the cadmium ion adsorption capacity of Escherichia coli, and belongs to the technical field of genetic engineering. E. coli BL21 to Cd 2+ , and the unit point mutation of T16C, K19C and S45C to CeMT2 can significantly improve the Cd 2+ binding capacity of CeMT2, and the cell Cd 2+ concentration of the T16C, K19C and S45C mutants is increased by 1.32 times, 1.50 times and 1.41 times, respectively. E. coli The recombinant expression of CeMT2 (K19C) and LmCadC in BL21 can obviously improve the cadmium ion adsorption capacity of Escherichia coli, and the maximum adsorption capacity reaches 8.5 mg / g.

The invention provides an LIBS (Laser-induced Breakdown Spectroscopy) rapid quantitative detection method for cadmium element in water, which comprises the following steps: adsorbing cadmium ion solutions with different concentrations through fiber membranes to prepare a solid sample, collecting spectral data by LIBS and preprocessing, extracting the spectral line intensity of the cadmium element, establishing a unary linear regression model, comparing the model correlation of different fiber membranes, and screening an optimal substrate. And carrying out EDTA modification and then carrying out modeling again so as to obtain a final quantitative detection model. The detection efficiency and accuracy can be improved, and a reliable technical means is provided for rapid detection of water heavy metal pollution.

The invention discloses a method for improving cadmium removal efficiency by adjusting a pH value. The method is characterized by comprising the following steps: detecting the initial concentration and the initial pH value of cadmium ions in a phosphoric acid solution or wastewater; the method comprises the following steps: adjusting the pH value of a phosphoric acid solution or wastewater to 2.1-3.0, adding a cadmium removal agent, controlling the temperature at 40-70 DEG C, reacting for 10-30 minutes, and filtering the phosphoric acid solution or wastewater to obtain the purified phosphoric acid solution or wastewater. According to the method, the pH value is adjusted to the optimal interval, the cadmium removal aid is added, and the temperature is controlled, so that the cadmium removal rate is stably increased to be greater than or equal to 98% from 75-85% of a traditional process, and the loss rate of the added cadmium removal aid is reduced to be less than 5% from 15%. The loss rate of main components of the treated phosphoric acid is lt; 0.3% (about 0.8% in the traditional process), and no secondary pollutants (such as hydrogen sulfide gas) are introduced.

The invention discloses heavy metal developing test paper based on a carbon quantum dot composite material as well as a preparation method and application thereof, and belongs to the technical field of heavy metal detection. The heavy metal chromogenic test paper comprises a quantitative filter paper substrate, a composite indicator and a colloid protection layer, wherein the composite indicator is prepared from a silk fibroin-anthocyanin compound, fluorescent carbon-based quantum dots and rich-pore carbon nitride, and is loaded on the substrate through mesoporous silicon balls; and the colloid protection layer is a mixed colloid solution of a masking agent and a sensitizer. The preparation method comprises the following steps: independently preparing the components, constructing the composite indicator, loading the meso-porous silicon balls and coating the protective layer. According to the invention, on-site rapid semi-quantitative detection of cadmium ions and ferric ions in soil or water can be realized, the operation is simple and convenient, the cost is low, and on-site screening requirements are met.

The application relates to a preparation method and application of a fluorescent probe for continuously detecting cadmium ions and glutathione, and relates to the field of detection of cadmium ions and glutathione, in particular to a preparation method and application of an isoflurone fluorescent probe. The application solves the problem that the existing fluorescent probe detection method cannot realize continuous recognition of cadmium ions and glutathione under the same test condition. The preparation method of the probe is as follows: (E)-2-(3-(3-formyl-4-hydroxy styryl)-5,5-dimethylcyclohex-2-en-1-ylidene) propanedinitrile is condensed with quinoline-2-formylhydrazine to obtain the fluorescent probe XL. The fluorescent probe prepared in the application can highly selectively and quickly recognize cadmium ions, and the complex of the probe and the cadmium ions has good recognition selectivity for glutathione and is not interfered by other amino acids and anions. The detection method constructed in the application is sensitive and efficient, does not need expensive large-scale instruments and professional experimenters, and can realize detection of glutathione in a water body environment.

The invention relates to the technical field of food microorganisms, in particular to a Saccharomyces cerevisiae BR24 (saccharomyces cerevisiae BR24) and application of the Saccharomyces cerevisiae BR24. The Saccharomyces cerevisiae BR24 is preserved in the China General Microbiological Culture Collection Center on December 23, 2024, and the preservation number of the Saccharomyces cerevisiae BR24 is CGMCC (China General Microbiological Culture Collection Center) NO.33166. The Saccharomyces cerevisiae BR24 is named as Saccharomyces cerevisiae BR24. The Saccharomyces cerevisiae BR24 provided by the invention shows good tolerance in a cadmium exposure environment, and by combining with cadmium ions, the level of serum transaminase is reduced, and the expression of metallothionein is promoted, so that the protection and recovery of liver functions are realized.

The application provides a method for treating industrial wastewater by homogeneous catalytic wet oxidation, and a catalyst used in the method is a complex soluble transition metal salt, wherein cerium ions are used as a main catalyst, and one or more of cobalt ions, copper ions, manganese ions, iron ions and cadmium ions are used as auxiliary catalysts. Through cooperation of the main catalyst and the auxiliary catalyst, the COD removal rate of the wastewater reaches more than 99%. The method has a short reaction residence time and high wastewater treatment efficiency, and can be widely used in industrialized catalytic wet oxidation treatment of high-concentration COD wastewater.

This invention belongs to the technical field of metal ion adsorption materials, specifically a method for preparing an adsorbent and a method for determining the soluble zinc content of raw materials used in the ammonia chloride process for producing electrolytic zinc. This invention modifies the surface of manganese dioxide with a thiourea-based silane coupling agent, grafting a silane coupling agent containing a thiourea structure onto the surface of manganese dioxide. The adsorption of lead, copper, and cadmium ions in solution is achieved using the manganese dioxide matrix and the thiourea-based silane coupling agent on the matrix surface, while effectively preventing the adsorbent from adsorbing zinc ions from the solution. When the adsorbent prepared by this invention is used to determine the soluble zinc content of raw materials used in the ammonia chloride process for producing electrolytic zinc, it exhibits a small testing error and can effectively improve the accuracy of soluble zinc content determination.