95 results about "Anodic stripping voltammetry" patented technology

System, method, and test strip for solid phase, electrochemical, quantitative analysis of analytes contained in biological fluid samples. Preliminary to analysis, a test sample solution can be applied to a sample collection pad associated with the solid phase test environment of the test strip. The test sample solution and a test kit reagent are thereby initially contacted, under assay conditions, within this solid phase test environment, and caused to migrate along a fluid pathway therein. Irrespective of the assay format (competitive assay, sandwich assay, etc.), a test kit reagent (e.g. labeled substance) and the analyte of interest (e.g. proteins, hormones or enzymes, small molecules, polysaccharides, antibodies, nucleic acids, drugs, toxins, viruses or virus particles, portions of a cell wall and other compounds which have specific or characteristic markers that permit their identification), either interact with one another to form a complex, or, alternatively, compete with one another for interaction with another test kit reagent, resulting in the concentration of an indicator substance within a delimited area of the solid phase. Thereafter, the delimited area of the test strip is subjected to electrochemical analysis and the results determined by monitoring an electrochemical transition in the form of an indicator, or derivative of the indicator (e.g. indicator species), by potentiostatic or potentiometric quantitative analysis (e.g. anodic stripping voltammetry). This electrochemical transition of the indicator has a characteristic electrical fingerprint that can be measured and which, when compared to a standard, can be correlated with the concentration of the analyte in the sample. This method is suitable for the determination/monitoring of therapeutic range of drugs (anti-convulsants drugs), determination of critical and potentially dangerous levels of endogenous materials which are indicative of disease states (prostate cancer), and numerous other applications presently requiring elaborate and time-consuming clinical laboratory analysis.

The invention discloses a method for quickly detecting lead and cadmium by adopting scanning anodic stripping voltammetry. The method comprises the following steps: a sample to be tested is prepared; lead or cadmium standard liquid is prepared; a three-electrode system consisting of glassy carbon electrodes plated with mercury films, platinum wire counter electrodes and Ag/AgCl reference electrodes is assembled; parameters are set and the scanning anodic stripping voltammetry is adopted to respectively implement parallel determination for current values between working electrodes and reference electrodes of each standard liquid solution until the relative standard deviation of readings is not more than 5%; lead and cadmium heavy metals of the sample are measured through detecting the current values between the working electrodes and the reference electrodes; a working station automatically calculates to obtain detecting results through automatically searching peaks to determine each curve peak area. The detecting method has the advantages of high sensitivity, good accuracy, reduction of mercury pollution, high electrode stability and good reproducibility, and can be applied to the detection of the heavy metals of lead and cadmium with conventional trace and ultratrace.

The invention relates to a multiparameter water quality heavy metal automatic online monitor based on the anodic stripping voltammetry. The monitor is characterized in that: the monitor comprises an electrochemical detection device, a control system, and a liquid charging device, a reaction device and a liquid discharging device which are respectively connected with the control system; the liquid charging device and the liquid discharging device, which jointly comprise peristaltic pumps, a precise syringe pump and six connection solenoid valves, are connected with the reaction device through pipelines to send a solution to the reaction device or discharge the solution from the reaction device; and the reaction device which is formed by inserted electrodes and an electrolytic cell with a stir bar provided therein is connected with the electrochemical detection device and can timely obtain effective data. By adopting the anodic stripping voltammetry in the invention, the simultaneous determination of multiple parameters can be realized, the reagent consumption is less, the apparatus is simple, the determination lower limit can be reduced by 2-3 orders of magnitude, and the chroma and the turbidity have no influences on the monitor, so the monitor can be used for the analysis of surface water and purified water.

The invention discloses an electrochemical sensor for detecting heavy metals. The sensor comprises a glassy carbon electrode serving as a working electrode in a three-electrode system, wherein ordered mesoporous carbon is modified on the surface of the detection end of the glassy carbon electrode; polyaniline and 2-mercaptoethanesulfonate are deposited on the ordered mesoporous carbon. A preparation method comprises the following steps of dispersing the mesoporous carbon into an organic solvent to obtain a mixture, then dispensing the mixture onto the surface of the glassy carbon electrode, and depositing polyaniline and 2-mercaptoethanesulfonate on the surface by an electrochemical cyclic voltammetry to prepare the electrochemical sensor. An application step comprises the following steps: putting the reaction end of the glassy carbon electrode of the electrochemical sensor into a solution to be measured, then connecting to an electrolytic basin of the three-electrode system, and implementing the detection on the concentration of heavy metal ions by a differential pulse anodic stripping voltammetry. The electrochemical sensor for detecting the heavy metals is low in cost, easy to manufacture, high in sensitivity, low in detection lower limit, high in interference resistance, easy to apply and operate and safe and pollution-free to the environment.

An anodic stripping voltammetric mechanism-based online automatic monitoring system for heavy metal ions in water takes electrochemical anodic stripping square wave method as a detecting mechanism and mainly comprises a system control molecule, a water sample filtering molecule, a water sample pretreating molecule, a sensor molecule and an analyzing molecule. The online automatic monitoring system for the heavy metal ions in water can continuously monitor multiple heavy metal ions in water on the spot in real time and perform pre-warning process according to whether the heavy metal content exceeds a standard or not. The online automatic monitoring system for the heavy metal ions in water is relatively low in cost, convenient to carry and easy to operate, can achieve remote control and data networking, and has a wide application prospect in routine water quality detection, real-time monitoring, pre-warning and prevention and emergency processing.

The invention discloses an electrochemical removal method for heavy metals in breeding circulating seawater, belonging to the technical field of water treatment. The method comprises the following steps: firstly, adjusting the pH value of seawater to be treated to 1.0-2.4, and removing heavy metals in the seawater by utilizing a three-electrode system in an electrochemical mode; testing the concentration of the surplus heavy metals in the treated seawater by utilizing the three-electrode system in an anodic stripping voltammetry mode; representing the removal effect; and finally, adjusting the pH value of the seawater which is completely treated by adding sodium hydroxide, and adjusting the pH value by adding fresh water to the salinity required for actual breeding. The method is high in application current efficiency and low in material consumption and running cost, and is simple to operate and easy to learn without special training; and moreover, work electrodes are less vulnerable to poisoning, namely, the work electrodes are not be polluted. Five kinds of heavy metals in the seawater can be simultaneously removed efficiency and rapidly. The heavy metal removal effects of the method can be represented by only one piece of equipment without any other auxiliary materials or conditions.

The invention relates to a monodispersive bimetal Au/Pt nano-particle modified electrode for detecting mercury in water and a preparation method thereof. The preparation method of the electrode comprises the following steps of: adding chloroplatinic acid to 3,3',5,5'-tetramethylbenzidine to obtain a purple precipitate, i.e. a Pt(II) doped organic nano fiber material; modifying the organic nano fiber material containing Pt(II) onto the surface of a glassy carbon electrode and then putting the modified glassy carbon electrode in a chloroauric acid solution; and carrying out electrochemical reduction by adopting cyclic voltammetry, wherein in the reduction process, the chloroauric acid is reduced into simple substance Au, and partial Pt(II) doped in the organic nano fiber material is also reduced into simple substance Pt, thereby forming a glassy carbon electrode which is adhered with Au-Pt bimetal nano particles on the surface and modified by a three-dimensional porous composite membrane with a network-shaped structure by using organic fibrous nano material as a supporting skeleton. The electrode can be used for detecting the content of mercury by adopting anodic stripping voltammetry, and has low detection limit to 0.008ppb, high sensitivity, strong selectivity and convenient and quick operation.

The invention relates to an electrochemical method for detecting microscale and trace arsenic and heavy metals by a carbon material modified working electrode and belongs to the fields of food, health, environmental monitoring and the like. According to the invention, a working electrode is modified mainly by the utilization of a common carbon material such as graphite, carbon black, active carbon and the like, and microscale and trace arsenic and heavy metals undergo quantitative analytical determination by anodic stripping voltammetry. The working electrode only needs to be coated with the carbon material for direct testing. By adding microscale nafion or adding a proper amount of bismuth ions into a solution to be tested, sensitivity of the working electrode can be greatly raised. The electrode modification material is cheap and easily available. The modification process is simple and fast, and one or more microscale and trace arsenic and heavy metals can be rapidly detected at the same time. Sensitivity is high; performance is stable; and detection limit is low. The method has a very good promotion and application prospect. The carbon material is the first choice as an actual working electrode coating material for the electrochemical method for rapidly detecting microscale and trace arsenic and heavy metals.

The purpose is to measure the concentration of cadmium in a food with high accuracy in a simple manner. A food which is to be measured on the cadmium concentration is weighed precisely and pulverized. The pulverized sample is subjected to an ashing treatment by strong heating. The resultant sample is mixed with an acid and the mixed solution is shaken. A residue is removed from the mixed solution to produce a solution, and the solution is subjected to an electrochemical measurement. The method for the electrochemical measurement to be employed is an anodic stripping voltammetry or the like. The working electrode to be used in the electrochemical measurement is a copper electrode or the like. The temperature to be employed for the ashing treatment by strong heating is equal to or higher than the melting point of zinc and equal to or lower than the boiling point of cadmium, and the solution to be subjected to the measurement is adjusted to pH 3.5 to 5.5.

The invention relates to the improvement of a cathodic stripping voltammetric method, in particular to a method for normatively adding another kind of internal standard metal ions with electrical activity into a reaction system to eliminate the influence on a detection result due to factors such as the non-uniformity of charges on the surface of a screen electrode, and the like and correct data obtained for detecting the concentration of metal ions by a voltammetric detection method so as to improve the accuracy of a detection result of an anodic stripping voltammetric method.

The invention relates to a method for detecting trace trivalent arsenic through two-signal anodic stripping voltammetry, wherein a working electrode is a gold electrode, a reference electrode is a saturated calomel electrode (SCE) or a silver/silver chloride electrode; and a counter electrode is a platinum, carbon or gold inert electrode; supporting electrolyte solution includes neutral phosphate buffer solution, B-R buffer solution with pH 1.81 to 8.95, or sulphuric acid solution with 0.1 to 0.5 mol.L-1; under the negative potential (-1.1 to -0.1 VvsSCE), test solution is mixed for enrichment for 300 to 600s, so that As (III) is reduced to As (0) to be enriched to the surface of the working electrode; the solution is on standing for 10 to 20s; when forward scanning reaches a certain electric potential point between 1 to 1.6 VvsSCE, the enriched As (0) is electro-oxidized and stripped into the As (III), and the As (III) is further electro-oxidized into As (V); and the trivalent arsenic in the test solution is calculated by the prior art according to the oxidation current double-response signals generated through detection. The method has more accurate detection result, high sensitivity, better property for resisting interference of materials as copper ion, obtains satisfactory result by being applied to the sample detection, is simple and quick, and can be widely applied in fields as environmental monitoring, food safety and bioelectrochemistry.

Measurement of arsenic in an aqueous solution is provided. The pH of the aqueous solution is adjusted to a pH of about 7.0 or higher. The pH adjusted aqueous solution is then analyzed using anodic stripping voltammetry to obtain an indication of a quantity of arsenic in the solution. In one aspect, the pH is adjusted using a phosphate buffer.

The invention discloses a method for judging whether heavy metals in water exceed the limit. The method comprises the following steps of: S10, preparing a solution to be tested; S20, setting detection parameters at an electrochemical work station; S30, detecting a water sample by an anodic stripping voltammetry method so as to obtain a stripping voltammetry diagram of the water sample, wherein an X-axis is taken as a voltage axis, and a Y-axis is taken as a current axis; S40, searching the starting point and the final point of each peak according to the stripping voltammetry diagram in the electrochemical work station; S50, calculating the peak height according to the starting point and the final point of the peak in the electrochemical work station; and S60, judging whether the heavy metals in the water sample exceed the concentration limited by the national standard GB5749-2006 according to the peak height of each peak in the electrochemical work station. Compared with the prior art, the method has the advantages of less possibility of peak omission, high accuracy and simplicity in detection process.

The invention discloses application of a filter paper adsorbent to direct electrochemical detection of lead in a water sample. The application is realized by adopting the steps of: punching Waterman No.1 filter paper to obtain a round paper sheet with the diameter of about 7mm through a puncher, then dripping 10 microlitre of an acetic acid buffer solution (with the pH value of 4.5) to the filer paper, drying at room temperature, then adding 10 microlitre of 500ppb bismuth nitrate solution, and drying at room temperature; before measurement, covering the filter paper on the surface of a screen printing electrode (Gwent group, Torfaen, United Kingdom), dripping 10 microlitre of water sample on the filter paper, and measuring with the frequency of 20Hz and the potential amplitude of 5mV according to an electrochemical anodic stripping voltammetry; depositing for 120s under -1.40V in an electrochemical way, and balancing for 30s; and carrying out anodic scanning from -1.40V to -0.40V, wherein before each measurement, stopping for 60s under +0.50V to clean the electrode. The method is used for determining the lead below 100ppb and has the errors within 6%.

The invention relates to an electrochemical method for detecting micro-arsenic, trace-arsenic and heavy metal by a composite material modified working electrode and belongs to the fields of food, health, environmental monitoring and the like. According to the invention, a working electrode is modified mainly by the utilization of a composite material formed by a common carbon material and g-C3N4, and micro and trace arsenic and heavy metal ions undergo quantitative analytical determination by anodic stripping voltammetry. The working electrode only needs to be coated with a graphene/g-C3N4 composite material for directly testing. Microscale nafion is added or bismuth ion is added into a solution to be tested. Then, detection limit of arsenic and heavy metal ions can be obviously raised. The electrode modification process is simple and fast; sensitivity is high; performance is stable; and microscale and trace arsenic and heavy metal ions can be detected rapidly. The method of the invention has a great promotion and application prospect.

The invention relates to double-channel anodic stripping voltammetry, which comprises the following steps of: (1) preparing a standard solution and a supporting electrolyte solution; (2) detecting a channel 1 and a channel 2 by using a three-electrode system; (3) adjusting the potential of a working electrode of the channel 1 to be -1.4 to -1.0 V vs saturated calomel electrode (SCE), adjusting the potential of a working electrode of the channel 2 to be -0.8 to -0.1V vs SCE, enriching at the stirring rate of 350 to 450rpm for 290 to 590s, stopping stirring, and standing for 10 to 30s; and scanning the potential of the channel 1 forwards until the potential is -0.3 to 0V vs SCE, scanning the potential of the channel 2 forwards until the potential is 1.3 to 1.6V vs SCE, and thus acquiring oxidation current response signals; and (4) adding a solution to be detected, and detecting by a standard addition method. By the double-channel anodic stripping voltammetry, trace lead, cadmium and trivalent arsenic can be detected simultaneously, and a detection effect is good.

The invention discloses a preparation method of an electrochemical sensor for trace lead ion detection, belonging to the technical field of environmental detection and analysis. The method comprises the following steps: step 1: enabling gelatin-based microcapsules, which are prepared through a complex coacervation method, to be frozen and dried, and enabling carbonized microcapsule powder to be ultrasonically dispersed in a chitosan acetic acid solution; step 2: taking 5 mu L of carbonized microcapsule dispersion liquid, which is prepared in step 1, to serve as an electrode material so as to modify the surface of a glassy carbon electrode to act as a working electrode; step 3: adding different concentrations of lead ion electrolyte into a buffer solution to form 5 mL of a to-be-tested solution, inserting an electrode system in step 2 into the lead ion electrolyte, and enriching lead ions in the electrolyte at constant voltage; step 4: obtaining the standard curves of peak current values and lead ion concentrations by adopting a differential pulse anodic stripping voltammetry; and step 5: detecting lead ion concentrations in to-be-tested samples. The working electrode modification material prepared by the invention has the advantages of simple preparation, low cost, controllable structure, good repeatability and the like.

The invention relates to a method for microplate fixing and nanometer lead sulfide marker electrochemical detecting genetically modified soybeans, which is characterized in that: the method comprises the following steps that: an amplification reactant namely a double-strand target sequence of an exogenous gene CP4 EPSPS to be detected is obtained through loop-mediated isothermal amplification, the reactant amplimer strain is exogenous gene CP4E PSPS of GTS 40-3-2 genetically modified soybeans, the double-strand target sequence is pyrolyzed to single-strand target sequences in water bath to fix on a microplate, and nanometer lead sulfide is led to marking a probe sequence from the exogenous gene CP4E PSPS to obtain a marked probe sequence, the marked probe sequence and the target sequence fixed on the microplate are performed molecular hybridization, and performed electrochemical detection with coordinate mercury plating anodic stripping voltammetry, aiming to electrochemically detect the exogenous gene (CP4 EPSPS) of the detected genetically modified soybeans. The method for microplate fixing and nanometer lead sulfide marker electrochemical detecting genetically modified soybeans has the advantages of rapidness, strong specificity, high sensitivity and convenient use.

The invention discloses a cadmium lead electrochemical detection method based on sulfur-doped graphene. An electrochemical sensor involved in the method is composed of a polysulfide/graphene-Nafion modified working electrode, an Ag/AgCl reference electrode, a Pt wire counter electrode, an electrolytic tank and an electrochemical workstation. The adopted electrochemical technology is differential pulse anodic stripping voltammetry. The sensor has a cadmium ion detection range of 2.0-300microgL<-1>, a lead ion detection range of 1.0-300microgL<-1>, and the detection limits are 0.67microgL<-1> and 0.17microgL<-1> respectively, and are both 4.5 times and 59 times lower than standard drinking water values given by WHO. At the same time, the sensor shows good reproducibility, stability and anti-interference performance. In detection of the content of lead and cadmium ions in tap water, the sensor shows good sensitivity and reproducibility. The sensor can accurately, quickly and simultaneously detect the content of cadmium and lead ions on site, and therefore has good practical application prospect.

The invention introduces a method and a device for automatic monitoring of water chemical oxygen demand (COD) combined with heavy metal ion concentration. The method is based on a three-electrode system with boron-doped diamond (BDD) membrane electrodes, tests COD of a water sample by an electrochemical anodic oxidation method, and tests heavy metal ion concentration of the water sample by anodic stripping voltammetry (ASV). The BDD electrodes are used both as an anode for testing water sample COD and as a working electrode for testing water sample heavy metal ion concentration, which realizes combined testing of COD and heavy metal ion concentration. With an integrated electrolytic bath, ultrasonic wave and constant temperature measures, the method and the device of the invention are economic and practical, are reliable in testing results, and are good in stability.

The invention relates to the technical field of food detection, in particular to a method for detecting heavy metals in dried aquatic food. The method comprises the following steps: preparing a graphene/Bi/Nafion composite material by using an electrochemical deposition method, and using the graphene/Bi/Nafion composite material as a working electrode for detecting trace amounts of heavy metals Pband Cd in a digestion solution; and preparing an Au/graphene composite material by using a microwave radiation method, and using the Au/graphene composite material as a working electrode to detect the trace amount of heavy metal Hg in the digestion solution. The trace amount of the heavy metal in the dried aquatic product is determined by using the anodic stripping voltammetry, and compared witha traditional mercury electrode, the electrode designed by the invention is an environment-friendly electrode and does not cause secondary pollution to the environment; compared with a traditional spectrum detection method, the detection method designed by the invention has the characteristics of simple operation, short analysis time and low instrument preparation cost, so that the detection method has a good application prospect in detection of heavy metals in dried aquatic products.

It is a reagent for measuring the marked heavy metal component, which substitute the containing heavy metal ion in the sample before using the method of anodic stripping voltammetry for measuring. The reagent comprises one to three percent of soluble chromate salt, one to five percent of potassium salt or sodium salt, 0.01 to 0.2 percent of soluble mercury salt for guarding electrode, and a organic solvent with one to three ph value to increase dispersibility and eliminate foams. The said reagent is combined with electrochemical measuring device and is characterized by quickness, convenience, high accuracy and reproduction ability.