39 results about "Amperometric detector" patented technology

The invention provides a detection method for galacto-oligosaccharide based on biological enzyme technology, which belongs to the technical field of food engineering. According to the invention, at first, the method of removing proteins by using trichloroacetic acid and lead acetate is employed for pretreatment of an object to be detected, and membrane filtration is utilized to remove impurities so as to obtain a sample to be detected; then, sodium hydroxide and sodium acetate with different concentration are utilized for ion exchange and gradient elution; finally, a four-potential pulsed amperometric detector is used for detection. The invention is applicable to separation and detection of cow's milk containing galacto-oligosaccharide and a variety of galacto-oligosaccharide components in a galacto-oligosaccharide solution system; employment of ion chromatography, utilization of the methods of ion exchange and gradient elution for separation of galacto-oligosaccharide and cooperativedetection with the four-potential pulsed amperometric detector enable contamination and interference to an analytical column, the detector and the like caused by macro-molecular substances such as proteins, fat and emulsifiers which might exist in the sample to be eliminated, thereby allowing accurate and rapid detection to be achieved.

The invention discloses a device and a method for detecting total cyanide and sulfide in a water solution by employing direct conversion. The method comprises the following steps: feeding a sample solution of which the pH is greater than or equal to 11 into a six-way valve quantitative loop to quantify through an online filter, feeding excessive sample solution into a liquid waste bottle; switching a six-way valve, pumping a pure water solvent as a carrying current, pushing out the sample solution, and pumping a water solution containing a stabilizer and an exchanger in advance; after mixing with the sample coming from quantitative loop samples, switching a three-way valve, and refluxing into a storage bottle, further pushing the solution to be mixed evenly in a mixing pipe by virtue of the pure water solvent; entering a photolysis device to carry out photolysis until reaching a capture column in the six-way valve in an ion chromatograph; locking a to-be-detected object, feeding a non-to-be-detected object into the liquid waste bottle; rising the capture column by using an eluting solution, and entering a separation post; sequentially discharging the sulfide and cyanide; and respectively detecting the sulfide and the cyanide by virtue of an ampere detector, and then rinsing the separation column in a reinforcing manner. Compared with an existing national standard method, the method disclosed by the invention is green, safe, environment-friendly, and little in interference; the analysis time, the laboratory safety and the cost are obviously improved; and use of a toxic reagent is also reduced.

The invention relates to a method for measuring hydrogen sulfide in mainstream cigarette smoke, in particular to an ion chromatography method for measuring hydrogen sulfide in mainstream cigarette smoke. The invention provides a method for directly measuring hydrogen sulfide in mainstream cigarette smoke, in order to solve the problem that complete capture and derivatization indirect measurement of hydrogen sulfide in mainstream cigarette smoke are susceptible to interference in prior arts. In the inventive method, an alkaline solution containing ascorbic acid, zinc acetate, ethylenediamine and sodium hydroxide is adopted to capture hydrogen sulfide in the gas phase of cigarette smoke, and anion exchange chromatographic separation and silver working electrode-equipped pulsed amperometric detector are adopted to directly measure hydrogen sulfide (sulfur ions) in the mainstream cigarette smoke. Compared with a conventional method, the inventive method has simpler operation, higher safety and higher interference resistance.

An image forming apparatus has: an image supporting member; a charger in proximity to the image supporting member; a power source unit configured to apply charging voltages to the charger sequentially, the charging voltages including alternating voltages having different peak-to-peak voltages, respectively; an amperometric detector configured to detect values of alternating currents flowing in the charger during application of the charging voltages; and a processor configured to carry out a first charging voltage determination process or a second charging voltage determination process requiring a shorter time than the first charging voltage determination process selectively based on a detection result of the amperometric detector. The processor carries out the first charging voltage determination process or the second charging voltage determination process selectively in accordance with a difference between an ambient temperature at a previous time of carrying out the first charging voltage determination process and a current ambient temperature.

The invention provides a liquid phase micro-extraction device for complex matrix sample on-line pretreatment of a capillary electrophoresis-ampere detector as well as a usage method thereof, a liquid phase micro-pumping device of the device is fixed on a fixed mount, the lower end of the liquid phase micro-pumping device is nested with a section of U-shaped hollow fiber pipe, and a capillary sample inlet end and an electrode are inserted into the other end of the hollow fiber pipe, the U-shaped hollow fiber pipe is positioned in a sample container, and a stirring device is also arranged on the sample container; and the liquid phase micro-extraction in the complex matrix sample pretreatment can be implemented according to the device of the invention. The invention has a complex matrix sample liquid phase micro-extraction pretreatment device, a capillary electrophoresis device and an ampere detector connected together to form an integral device, the range of detected substances is extended, and the sensitivity, reproducibility, stability and reliability for separating capillary electrophoresis are improved; and the device has advantages of small volume, simple structure, simple operating method, low cost, good reproducibility of the method, and convenient sample analysis after pretreatment.

The invention discloses a preparation and using method for a glucose ampere detector based on a novel nanocomposite material. The glucose ampere detector comprises a carbon nano tube, a platinum nano particle, a polymeric ionic liquid membrane and a glassy carbon electrode modified by glucose oxidase and used as a working electrode, wherein a platinum wire is used as a counter electrode; a mercurous chloride electrode is the three-electrode system of a reference electrode. The using method is as follows: under the three-electrode system, an electrochemical workstation is used for measuring the glucose content in the detecting process. According to the invention, compared with the conventional method, the sensitivity and the specificity are higher, and the detection is limited to 1 X 10-7 mol / L; in addition, the glucose ampere detector is simple in preparation and stable in property, can be reutilized, and is short in sample detecting time and convenient to operate.

The invention discloses a method for detecting total cyanide and sulfide through online photolysis-noncontact diffusion-chromatographic separation. The method mainly comprises the following steps: in a flowing injection system, absorbing a sample into an acid solution flow to be conveyed into a photolysis device for photolysis so that cyanide in different forms is turned into hydrogen cyanide and sulfide is turned into hydrogen sulfide, passing the solution through an acid canal of a gas-liquid membrane separation diffusion unit to be diffused into an alkali canal on the other side through a hydrophobic membrane in a noncontact manner; keeping the cyanide and the sulfide diffused in an alkaline absorbing solution; by alternately switching a second six-way valve and a third six-way valve, driving a matter to be detected in a buffer pipe through a water solution in an injection pump, trapping the matter to be detected in the buffer pipe through a trapping column in the third six-way valve and locking the matter to be detected; washing the trapping column through leacheate, entering a separation column, discharging the cyanide and the sulfide sequentially and detecting one by one through an ampere detector. The method disclosed by the invention is short in detection time, light in interference, sealed in process, high in sensitivity, low in damage on member, mild in condition and environmental friendly.

The invention relates to a method for detecting lactulose in milk.The method comprises the steps that lactose and lactulose in the milk react and are hydrolyzed into galactose, glucose and fructose through beta-D-galactosidase, glucose oxidase is added to oxidize most of the glucose into gluconic acid, finally catalase is added to remove hydrogen peroxide, and a testing solution is obtained; an ion chromatograph with an ampere detector is used for analyzing the testing solution, and the content of the lactulose is obtained.According to the method, the content of the lactulose in the milk can be accurately and sensitively measured by means of easy and convenient operation.

When analysing saccharides by HPAEC, the eluate from the column is typically analysed using a amperometric detector. According to the invention, amperometric detection is coupled with ultraviolet detection, with both methods being applied to the eluate. Thus the invention provides a method for analysing the eluate from a liquid chromatography column, wherein the eluate is analysed by both (a) amperometric detection and (b) ultraviolet detection. The information content derivable from using both sorts of detection advantageously exceeds that derivable from either of the two detection methods alone.

The invention relates to a method for identifying adulterated honey. The method comprises the following steps of: (1) pretreating a sample; and (2) determining whether the sample contains D-allulose or not by using an ion chromatography pulse ampere detector. The honey adulteration means that syrup containing Dpsicose is doped in honey. The specific method adopted in the step (2) comprises the following steps of: separating and detecting the D-allulose in to-be-detected liquid by using an ion chromatography pulse ampere detection method, determining the nature of the D-allulose in the sample by using the retention time, and quantifying the D-allulose in the sample by using an external standard method through an external standard curve method.

The invention discloses a detection method of total content of fructo-oligosaccharide in formula milk / milk powder. The detection method realizes enzymolysis treatment of the fructo-oligosaccharide by utilizing an enzymolysis method, and moreover realizes detection of the total content of the fructo-oligosaccharide in the formula milk / milk powder by adopting a universal high performance liquid chromatography-evaporative photodetector by selecting a specific chromatographic condition. The detection method has the advantages that the trouble that a special ampere detector for ion chromatography impulse is required to be used in the existing national standard method GB5009.88-2016 is overcome; the equipment cost is low; the universality is high; and the generalization performance is high. Compared with a detection result of the special ampere detector for the ion chromatography impulse used by the method GB5009.88-2016, an error is less than 5%.

The invention discloses a method for simultaneously and rapidly detecting amino sugar, neutral sugar and uronic acid in seaweed, and belongs to the technical field of analysis and detection of carbohydrate compounds in the food industry. The method comprises the following steps: extracting a seaweed polysaccharide crude product from a to-be-detected sample by adopting an ultrasonic-assisted waterextraction and alcohol precipitation method; removing protein in the extracted algal polysaccharide crude product by using a Sevage method, and hydrolyzing algal polysaccharide by using trifluoroacetic acid; after hydrolysis is completed, adding NaOH to neutralize the acidity of hydrolysate, and using the hydrolysate passes through a 0.22 micron filter membrane and then is used for detection of anion chromatography-pulse ampere detector. The method provided by the invention is simple and rapid, does not need derivation, greatly improves the applicability and recovery rate of the method, solves the technical problem of low efficiency when multiple detection technologies, multiple instruments and multiple pretreatment methods are adopted to determine multiple components at present, greatlyimproves the detection efficiency, and reduces the detection cost.

The invention provides an ion chromatography detection method of gentamicin B purity. The chromatographic conditions are as follows: octadecylsilane chemically bonded silica is used as a filler; the column temperature is 25-35 DEG C; the flow rate is 0.5-1.5ml / min; the injection volume is 10-20ul; and according to the method, a gold indicator electrode, a silver chloride silver reference electrodeand a stainless steel auxiliary electrode are used as pulse ampere detectors of a battery body, and the detection is respectively performed at + 0.05V, at an oxidation potential of +0.75V and a reduction potential of -0.15V according to a pulse duration used by the instrument. The ion chromatography detection method provided by the invention has the advantages of simple and rapid operation, highaccuracy and high precision, and is suitable for laboratories to detect the gentamicin B purity, and the detection can be performed in batches, so that the detection efficiency is improved.

The invention discloses a measurement method of the content of cyanide in drugs. The method comprises the following steps: (1), performing pretreatment on a drug sample through an acid distilling method: performing heating distilling through an acid distiller or a round-bottom flask, completely converting and separating out cyanide from the drug sample, and absorbing the cyanide through sodium hydroxide, so as to obtain a cyanide absorption liquid to be tested; (2), measuring the cyanide through an ion chromatography method: ensuring that the adopted chromatographic conditions are as follows:an ampere detector, an Ag working electrode, an Ag / AgCl reference electrode, an anion separating column, an anion protective column, injection volume of 25 micro liters, flow rate of 1.0 mL / min, temperature of 30 DEG C, and a NaOH solution with the flowing phase being 4mmol / L. The method has the advantages that the concentration of CN- presents a good linear relation within a measurement range, the detection limit is 0.0103 microgram / g, the sample adding standard recovery is 96.0 to 101.1 percent, and the degree of precision is 1.01 to 2.07 percent; the chromatographic conditions can obtain the superior detection limit and precision degree and smaller leaching time, the cyanide retention time can reach 7.78 min, and the lowest detection limit is 0.004 gm / L.

The invention discloses a method for ion chromatography detection of acarbose and belongs to the field of analysis and detection. The method utilizes high efficiency anion exchange chromatogram column separation and pulsed amperometric detector-based detection, utilizes a sodium hydroxide solution as a mobile phase and utilizes an external standard method for quantitative analysis. The lowest detection limit of acarbose is 0.15 microgram / L, a recovery rate is 96.8% to 102.2%, and reproducibility is in a range of 0.59% to 0.84% (RSD, n=5). The method has the advantages of high detection sensitivity and fast analysis speed and can be used for content detection and quality evaluation of acacosose products in related industries.

The invention belongs to a radiation detection device, in particular relates to a current type cadmium zinc telluride (CZT) detector with a compression joint structure and solves the technical problems of poor packaging structure of the CZT detector under the limited process and technical conditions, increase of leakage current, infirmness of electrodes, high preparation difficulty, instable performance, low customized product processing rate and the like of the packaged CZT detector. The current type CZT detector comprises a shielding shell, two cable adapters which are arranged outside the shielding shell, a through hole which is formed in the shielding shell, and a CZT crystal, conductive gasket rings, the electrodes and pressing covers, which are arranged in the through hole, wherein conductive layers are coated on the surface of two sides of the CZT crystal; the conductive gasket rings, the electrodes and the pressing covers are divided into two groups and symmetrically distributed on the two sides of the CZT crystal; the conductive gasket rings are respectively contacted with the two sides of the CZT crystal; the electrodes are contacted with the corresponding conductive gasket rings; and the pressing covers are used for fixing the electrodes and the conductive gasket rings into the shielding shell and pressed against the CZT crystal. The current type CZT detector is high in detection efficiency and detection sensitivity, and stable and reliable in performance.

The invention discloses a method of detecting trihydroxymethyl aminomethane (Tris) in a bioproduct by means of ion chromatography. The method comprises the following steps: drawing a concentration-peak area standard curve of Tris by means of an external standard method by adopting a pulse ampere detector and a post-column liquid supplementation deviating method through using CS16 cation-exchange chromatography to obtain a regression equation of the standard curve, wherein the mobile phase is a methanesulfonic acid solution and the post-column supplemented liquid is an alkaline solution; and calculating the content of Tris by means of the regression equation. According to the method, the lowest detection limit of Tris is 3.14<-5>mmol / L, the lowest limit of quantitation is 1.05<-4>mmol / L, the recovery rate is 93.8-100.1%, and the repeatability range is 0.10-0.52% (RSD, n=5). Without deviation and pre-treatment of a complicated sample, the method is neither interfered by acid-base groupscarried on proteins in the bioproduct and nor interfered by anions and cations in the sample, is high in detection sensitivity and high in analytical speed, and can be applied to content detection andquality judgment of Tris in the bioproducts in related industries.

The present invention provides a capillary electrophoresis-thermal working electrode-ampere detecting device and a method of producing the thermal working electrode. The device comprises a high-voltage separation system, an electrochemical detecting pool, a high-voltage power source earth terminal arranged in the detecting pool, an auxiliary electrode, a reference electrode and a thermal working electrode connected with an electrochemical analytical instrument, a platinum wire of the thermal working electrode connected with an end of a separation capillary and a heating element arranged on the platinum wire. Wherein, the electrochemical analytical instrument is connected with a computer workstation. Method of producing the thermal working electrode includes steps below: producing a heating circuit and a detecting terminal on the platinum wire, connecting the platinum wire with the separation capillary, etc. The present invention integrates the capillary electrophoresis, the thermal working electrode and the ampere detector into a whole device, thus expanding scope of detecting substance and improving repeatability, stability and reliability of connection between the separation capillary and the electrode. The device has the advantages of small size and easy arrangement and effectively avoids electrochemical detecting signals being interfered by heating current. The electrode has the advantages of simple production, easy utilization and high stability.

The invention discloses a device and a method for detecting total cyanide and sulfide in a water solution by employing direct conversion. The method comprises the following steps: feeding a sample solution of which the pH is greater than or equal to 11 into a six-way valve quantitative loop to quantify through an online filter, feeding excessive sample solution into a liquid waste bottle; switching a six-way valve, pumping a pure water solvent as a carrying current, pushing out the sample solution, and pumping a water solution containing a stabilizer and an exchanger in advance; after mixing with the sample coming from quantitative loop samples, switching a three-way valve, and refluxing into a storage bottle, further pushing the solution to be mixed evenly in a mixing pipe by virtue of the pure water solvent; entering a photolysis device to carry out photolysis until reaching a capture column in the six-way valve in an ion chromatograph; locking a to-be-detected object, feeding a non-to-be-detected object into the liquid waste bottle; rising the capture column by using an eluting solution, and entering a separation post; sequentially discharging the sulfide and cyanide; and respectively detecting the sulfide and the cyanide by virtue of an ampere detector, and then rinsing the separation column in a reinforcing manner. Compared with an existing national standard method, the method disclosed by the invention is green, safe, environment-friendly, and little in interference; the analysis time, the laboratory safety and the cost are obviously improved; and use of a toxic reagent is also reduced.

The invention discloses an online photolysis-non-contact diffusion-chromatographic separation method for detecting total cyanide and sulfide. Solution, so that different forms of cyanide into hydrogen cyanide, sulfide into hydrogen sulfide, flow through the acid channel of the gas-liquid membrane separation diffusion unit, non-contact diffusion through the hydrophobic membrane into the other side of the alkali channel; alkaline absorption The liquid will store the diffused cyanide and sulfide in it; through the alternate switching of the second and third six-way valves, the aqueous solution of the syringe pump drives the analyte in the buffer tube, so that the analyte in the buffer tube enters the trapping column in the third six-way valve , to lock the analyte; the eluent washes the trapping column, enters the separation column, cyanide and sulfide flow out in sequence, and are detected one by one by the amperometric detector. The invention has short detection time, less interference, airtight process, high sensitivity, little membrane damage, mild conditions and environmental protection.

The invention provides a method for measuring the content of plant polysaccharide, which comprises the following steps: degreasing a sample, removing small molecular compounds, performing reflux extraction with water, and performing microwave-assisted digestion to obtain plant polysaccharide hydrolysate. Monosaccharide in the hydrolysate is subjected to gradient elution through an ion exchange chromatographic column and a sodium hydroxide / sodium acetate solution and detected through a pulse ampere detector, the composition and content of monosaccharide generated by polysaccharide hydrolysis are measured, and the content of plant polysaccharide in the sample is calculated with the sum content of all monosaccharide as the standard. The method for measuring the content of the plant polysaccharide can effectively shorten the hydrolysis time of the plant polysaccharide, and then the content is measured by using the ion chromatography, so that a better choice is provided for the detection of the plant polysaccharide, and meanwhile, technical support and basic data are provided for controlling the quality of medicinal plants in plants and further researching the biological activity of the medicinal plants.

The invention relates to a method for identifying adulterated honey, which comprises the following steps: (1) sample pretreatment; (2) using an ion chromatography-pulse amperometric detector to determine whether the sample contains D-psicose; Described honey adulteration refers to mixing the syrup containing D-psicose in honey; The concrete method of step (2) is: the liquid to be tested is subjected to D-psicose by ion chromatography-pulse amperometric detection method. For separation and detection, the retention time is used to characterize D-psicose in the sample, and the external standard method is used to quantify D-psicose in the sample through the external standard curve method.

When analysing saccharides by HPAEC, the eluate from the column is typically analysed using a amperometric detector. According to the invention, amperometric detection is coupled with ultraviolet detection, with both methods being applied to the eluate. Thus the invention provides a method for analysing the eluate from a liquid chromatography column, wherein the eluate is analysed by both (a) amperometric detection and (b) ultraviolet detection. The information content derivable from using both sorts of detection advantageously exceeds that derivable from either of the two detection methods alone.

The invention provides a method for rapid determination of sodium formaldehyde sulfoxylate in a food additive. The method is characterized by: using dilute alkali to extract sodium formaldehyde sulfoxylate from a sample, removing impurities, then employing an anion exchange column to conduct separation, adopting an ampere detector to perform detection, carrying out qualitative diagnosis according to retention time, and performing quantification by an external standard technique. Compared with conventional methods, the method has simple pretreatment, needs no distillation, reduces false positives, and has the advantages of good sample stability, high accuracy, less matrix interference, as well as high sensitivity, thus having good promotion value.

The invention discloses a device and a method for amperometric detection of the total cyanide and sulfide of wastewater by online photolysis dialysis / chromatographic separation. A first peristaltic pump pumps alkaline in a container into a receiving-liquid cavity channel of a dialysis cell, the excessive solution flows through a quantitative ring in an ion chromatograph, then flows into a waste-liquid bottle and then is stopped; a second peristaltic pump injects a fixed-volume sample solution containing a stabilizing agent and an exchange agent into a filter and a photolysis device continuously to reach a sample cavity channel of the dialysis cell, and after components to be detected are bilaterally balanced by membrane dialysis, the first peristaltic pump is started and conveys received liquid containing the total cyanide and the sulfide into a quantitative ring of a six-way valve in the ion chromatograph; by switching of the six-way valve, leacheate flows through the quantitative ring and is separated from a separating column by a protective column and is detected out by an amperometric detector. The device and the method disclosed by the invention have the advantages that under the mild alkaline condition, all cyanides are converted into alkaline-metal cyanides by narrow-spectrum ultraviolet photolysis, so that not only is the classic process of strong-acid distillation or acidified ultraviolet photolysis and then membrane separation omitted, but also almost no membrane pressure is generated in operation, and the sample treatment is simple.

The invention relates to a method for detecting lactulose in milk.The method comprises the steps that lactose and lactulose in the milk react and are hydrolyzed into galactose, glucose and fructose through beta-D-galactosidase, glucose oxidase is added to oxidize most of the glucose into gluconic acid, finally catalase is added to remove hydrogen peroxide, and a testing solution is obtained; an ion chromatograph with an ampere detector is used for analyzing the testing solution, and the content of the lactulose is obtained.According to the method, the content of the lactulose in the milk can be accurately and sensitively measured by means of easy and convenient operation.

The invention discloses a determination method for glycine betaine in wolfberry fruits. The method comprises the following steps: (1) extracting wolfberry fruit samples with a water extracting solvent, and taking a filtering solution obtained by filtering as a solution to be detected; and (2) analyzing and determining glycine betaine in the samples by combining an ion chromatography with a pulse ampere detector. The invention establishes the method for determining glycine betaine in the wolfberry fruits by combining the ion chromatography with the pulse ampere detector. The method has good linearity; and the recycling rate is 90.8%-94.7%, the accuracy is 1.11% and the detection limit is 0.0366 micrograms / milliliter. According to the method, a toxic reagent is not used; and a test verifies that the method is applicable to rapid and batch detection of glycine betaine in various phytophagous and functional foods.

The invention discloses a device and a method for detecting cyanide in an aqueous solution. The detection device comprises a multi-way valve, a digestion device, a separator and an ampere detector; an interface of the multi-way valve is respectively connected with a sample conveying pipeline, an inlet and an outlet of the quantitative loop, a carrier solution conveying pipeline, a first waste discharge pipe and a mixed liquid conveying pipeline; a first mixer, a digestion device, a third mixer, a separator and a second waste discharge pipe are sequentially arranged on the mixed liquid conveying pipeline; the first mixer is connected with a first acid solution conveying pipeline; the third mixer is connected with a second acid solution conveying pipeline; the separator is divided into an acid system flow path and an alkali system flow path through a hydrophobic membrane, the acid system flow path is arranged on the mixed solution conveying pipeline, the two ends of the alkali system flow path are connected with the first alkali solution conveying pipeline and the ampere detector respectively, and an outlet of the ampere detector is connected with the third waste discharge pipe. According to the method, the sample preparation time can be saved to the maximum extent, the sample preparation frequency reaches 2min / sample, the detection limit is less than or equal to 0.0007 mg / L (0.7 ug / L), and the determination range is 0.002-0.5 mg / L.

The invention provides a determination method of polysaccharide distribution in a ferrosugar complex. The determination method comprises three steps of preparation of a sample solution, preparation of a mobile phase solution and detection by an integral pulse amperometry. According to the determination method, the ion chromatography is matched with the amperometric detector, the polysaccharide distribution can be detected, the sensitivity is high, and the detection limit can reach the ppm level.