37results about How to "Mild detection conditions" patented technology

The invention relates to the technical field of food processing, in particular to a method for determining eight sweetening agents in Baijiu by a high-performance liquid chromatography-low-temperature evaporative light scattering detector method. The method includes the steps of (1), standard solution preparation, (2) sample pretreatment, (3) sample detection, (4) calibration curve establishment and (5) resulting. The method for determining eight sweetening agents in the Baijiu by the high-performance liquid chromatography-low-temperature evaporative light scattering detector method has the advantages of mild detection conditions, simplicity, rapidity, good separation effects and capability of playing a positive role in improving laboratory detection efficiency and reducing detection cost.

The invention relates to a preparation method of a novel escherichia coli electrochemical sensor. According to the technical scheme, the surface of a glassy carbon electrode is carboxylated, and escherichia coli is linked to the surface of the glassy carbon electrode by virtue of a biologic coupling technique so as to prepare the escherichia coli electrochemical sensor; the glassy carbon electrode is taken as a substrate, the surface of the glassy carbon electrode is subjected to sodium hydroxide etching to be carboxylated, and then the escherichia coli is coupled to the surface of the glassy carbon electrode, wherein a coupling agent is 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide easer (NHS). The preparation method is characterized in that the escherichia coli electrochemical sensor with high sensitivity is obtained. The escherichia coli electrochemical sensor is high in stability and detection sensitivity, good in accuracy, and the detection efficiency is obviously superior to that of a conventional detection method. The preparation method comprises the following steps: (1) preparing an escherichia coli section chemical sensor; and (2) detecting electrochemical signals of the escherichia coli section chemical sensor. The novel escherichia coli electrochemical sensor is simple and convenient in preparation method, high in detection sensitivity and accuracy and high detection speed and is convenient for practical application.

The invention belongs to the technical field of analytical chemistry, and relates to a phosphate radical detection method, in particular to a phosphate radical colorimetric detection method based on bimetal MOF nano oxidase. Firstly, an ultraviolet absorption spectrum standard working curve is drawn, and then the phosphate radical content of a to-be-detected object is determined through the working curve. The invention further discloses a preparation method of the bimetallic (Ce / Zr) organic framework structure (MOFs) nano oxidase, namely Treated-UiO-66-(Ce / Zr). The method has the advantages ofmild conditions in the detection process, no need of other reagents, realization of convenient and rapid detection of phosphate radicals, low detection cost and simple operation; phosphate radicals are detected through a dual-mode calibration TMB / ABS + Treated-UiO-66-(Ce / Zr) system, the detection limit is as low as 14 nM, and the detectable range is as wide as 0.667-667 [mu] M; phosphate radicalsare detected by using a TMB / ABTS + Treated-UiO-66-(Ce / Zr) system, the measurement result of an actual sample is accurate, the response to the phosphate radicals is sensitive, and the detection of thephosphate radicals in the environmental drinking water can be realized.

The invention discloses a rhodamine derivative and its application in the detection of nitrite ions, and belongs to the technical field of detection. A carbonyl carbon atom in rhodamine and one aminonitrogen in 1,3-diaminopropane are condensed in the synthesis process to obtain a new compound different from common Schiff bases. A synthesis method of the compound has the advantages of simplicity,high yield, low cost, and good promotion and application prospect. Additionally, the compound used as a fluorescence probe for the nitrite ions in a water phase has the advantages of realization of detection in a near-neutral environment, mild detection conditions, strong interference resistance to other anions and cations, high sensitivity, realization of the detection limit of the nitrite ions being 0.768 [mu]M, and short response time.

The invention discloses a rapid glucose detection method. According to the method disclosed by the invention, a nanoscale GOx&AuNCs@ZIF-8 compound with high catalytic capability is prepared by utilizing a mild and environment-friendly mode. Compared with a uniform mixture of two free enzymes, namely AuNCs and GOX, the GOx&AuNCs@ZIF-8 compound has the advantages that the biocatalytic cascade of theGOx&AuNCs@ZIF-8 compound is enhanced by about 19.3 times, enzyme stability is high, enzyme dosage is small, cost is low, efficient and sensitive detection of glucose is realized, detection conditionsare mild, operation is simple and convenient, and a strong targeting property is realized. The rapid glucose detection method of the invention overcomes the problems of complicated sample pretreatment procedures and expensive instruments in chromatography, the problems of poor targeting property, poor sensor stability and demands for special electrodes and electrochemical equipment in an electrochemical method, and the problems of high cost of colorimetric sensors, large enzyme dosage, easy enzyme inactivation and the like in traditional enzyme method.

The invention relates to a method for detecting fosfomycin sodium in pharmaceutical wastewater by adopting an ion chromatography. The method comprises the following steps that (1) chromatographic condition: chromatographic columns include a low-volume hydroxyl system cathodic protection column and a high-volume anion exchange separation column, a suppressor is an electrolytic film suppressor, an electrical conductivity detector is used, and leacheate is a sylvite solution; (2) the preparation of a standard solution: a standard product of the fosfomycin sodium is mixed with ultrapure water to obtain into the standard solution; (3) the pretreatment of a sample: a sample to be detected is filtered by using a 0.45mum filtering film and then processed by a C18 colonnette so that organic matters in the water sample are removed; (4) a detecting method: the standard solution is added in an ion chromatograph, then a spectrogram is recorded, the position of a standard peak is determined, the area of a fosfomycin sodium peak is calculated, and a standard curve is drawn according to the calculated area of the peak; a testing sample is added in the ion chromatograph, then a spectrogram is recorded, and the concentration of the sample is calculated according to the area of the fosfomycin sodium peak. The method provided by the invention has the advantages that the detection repeatability of the fosfomycin sodium in the pharmaceutical wastewater is good, the detection limit is low, the sensitivity is high, the operation is simple, the detecting condition is gentle, the detection equipment and instrument are widely applied, the source of a leacheate sylvite solution is wide, and the configuration is simple, and the method is widely used for detecting fosfomycin sodium in the industrial wastewater.

The invention discloses a method for detecting related substances of a flunarizine hydrochloride preparation, which comprises the following steps: respectively taking a test solution, a contrast solution and an impurity mixed solution for high performance liquid chromatography detection, and respectively detecting the content of each impurity in the test solution at 210nm and 253nm, wherein peaksof the impurity A and 4, 4-difluorobenzhydrol are detected at 210 nm, and the impurity content is calculated according to an external standard method; and detecting other impurity peaks at 253nm, andcalculating the impurity content according to a self-contrast method. The method is easy to operate, short in analysis time, high in specificity and high in sensitivity, seven impurities can be effectively separated, the separation degree of two process impurities and five degradation impurities, the most difficult-to-separate impurity B and a main peak reaches 1.2 or above, and the separation degree of other impurities and adjacent peaks can all reach 1.5 or above.

The invention belongs to the technical field of mimic enzyme and analytical chemistry, and relates to a sulfuration modified CoOx-based alkaline phosphatase activity colorimetric detection method, which comprises respectively adding alkaline phosphatase with different activities and 1 mM HMPi to a 5 mL centrifuge tube, and reacting for 30-60 min; sequentially adding the vulcanization modified CoOxsuspension, TMB, H2O2 and an acetate buffer solution into the mixed solution, uniformly mixing the system, and reacting for 1-30 minutes; recording the absorbance at the wavelength of 652 nm by usingan ultraviolet-visible absorption spectrophotometer after passing through the film; drawing a calibrated ALP activity-absorbance standard working curve according to the absorbance measurement value of the TMBox and the corresponding ALP activity; repeating the above steps on the ALP sample to be detected, and comparing the ALP sample with the standard working curve to obtain the ALP activity. Themethod has the advantages of mild conditions in the detection process, does not need other reagents, realizes convenient and rapid detection of the ALP activity, is low in detection cost, simple in operation, has wide detectable range of 0.8-320 U / L, and realizes detection of the alkaline phosphatase activity in human serum.

The invention belongs to the technical field of in vitro diagnosis, and discloses a method for detecting E6 or E7 nucleic acid of an HPV16 or HPV18 virus based on RPA. A primer for efficiently and specifically amplifying E6 or E7 nucleic acid of the HPV16 or HPV18 virus is designed and screened out; HPV16 or HPV18 virus is amplified through an RPA reaction, and DNA or mRNA is included. The specificity reaches 100%, and the sensitivity is 10 copies per reacton. The RPA isothermal amplification system is fast in reaction, no complex temperature control system is needed, effective amplification of target genes can be achieved at the temperature of 37 DEG C to 42 DEG C, and the method is suitable for field fast detection of E6 or E7 nucleic acid of the HPV16 or HPV18 virus. The RPA detecting method is utilized for detection, the detection condition is mild, the detection time is short, and use is more convenient.

The invention discloses an Au-Ag nanometer core-shell material taking carrageenan as reducing agent as well as a preparation method and application thereof. The preparation method comprises the following steps: adding a chloroauric acid solution and an alkaline solution into a carrageenan aqueous solution, shaking well, reacting at 40 to 80 DEG C, cooling to room temperature after the reaction toobtain an orange solution, namely gold sol; and adding a certain amount of silver nitrate solution and an alkaline solution into the gold sol, shaking well and reacting at 80 DEG C to obtain the Au-Agnanometer core-shell material. The Au-Ag nanometer core-shell material comprises a nano-gold core body and a nano-silver shell layer, wherein the average particle size of the nano-gold core body is 10+ / -5 nm, and the average particle size of the nano-silver shell layer is 30+ / -5 nm. The Au-Ag nanometer core-shell material can serve as a compound similar to catalase for detecting hydrogen peroxideso as to prevent food from being oxidized or remove the hydrogen peroxide from the food. The Au-Ag nanometer core-shell material can develop color by itself, does not need to add a developer in the process of detecting the hydrogen peroxide and is mild in detection condition and simple in detection method.

The invention belongs to the technical field of analytical chemistry, and relates to a method for detecting nitrite ions based on ratio type colorimetry. The method comprises the following steps: sequentially adding 25 [mu] L of 1 mg / mL hollow MnFeO suspension, 30 [mu] L of 5 mM TMB solution and 1440 [mu] L of 0.2 M acetate buffer solution into a 2 mL centrifugal tube, and uniformly mixing; respectively adding NO2 <-> with different concentrations, wherein the final concentrations of the NO2 <-> in the system are respectively 3.33 [mu] M, 6.67 [mu] M, 10 [mu] M, 13.33 [mu] M, 20 [mu] M, 33.33 [mu] M, 50 [mu] M, 66.67 [mu] M, 83.33 [mu] M, 100 [mu] M, 120 [mu] M and 133.33 [mu] M; measuring an absorption spectrum by using an ultraviolet-visible absorption spectrophotometer, and drawing a standard working curve; and measuring an absorption spectrum of a to-be-measured NO2<->sample, and comparing the absorption spectrum with the standard working curve to obtain the NO2<-> concentration of the sample. According to the invention, the oxidation product TMBox of the hollow MnFeO + TMB system and the nitrite are subjected to a diazotization reaction so as to achieve the indirect detection of the nitrite, the detection process conditions are mild, the detection limit is as low as 0.2 [mu] M, and the detection of the nitrite in the food can be achieved.

The invention relates to a kit for detecting a respiratory syncytial virus and application of the kit. The kit comprises an RPA amplification reaction system and a CRISPR-Cas13a protease detection system, wherein the RPA amplification reaction system comprises an RPA amplification primer pair, and the CRISPR-Cas13a protease detection system comprises sgRNA (small guide ribonucleic acid), Cas13a protein and a probe. The invention further provides a corresponding detection method, the respiratory syncytial virus can be detected through the kit under the constant-temperature condition, and the kit has the advantages of being short in detection time, easy and convenient to operate, mild in detection condition, free of assistance of expensive professional instruments and the like. The kit and the corresponding detection method have good application prospects and have the potential to be applied to clinical detection.

The invention provides a method for detecting dihydroxybenzene in a water body by a colorimetric method. The method comprises the following steps: A) preparing cerium oxide loaded with Mn < 2 + >; furthermore, an accelerant can be added to carry out coordination encapsulation on the Mn element, so that the hydrophilicity of the particles is improved, and the adsorption effect of the particles on signal molecules is enhanced; b) dispersing the cerium oxide loaded with Mn < 2 + > in an organic solvent, coating the surface of the test paper with the cerium oxide, and drying to obtain the test paper; c) respectively mixing chromogenic substrate molecules with dihydroxybenzene standard solutions with different concentrations, dropwise adding the mixture to the surface of the test paper, and establishing a standard curve of color chromatic values and concentrations; and D) mixing the chromogenic substrate molecules with a water body sample to be detected, dropwise adding the mixture to the surface of the detection test paper, and obtaining the concentration of the dihydroxybenzene according to the chromatic value of the color. The detection method disclosed by the invention has the advantages of high stability, high efficiency, low cost, strong specificity and the like, is mild in detection condition, saves time and economic cost, and has an extremely good industrial application prospect.

The invention relates to a preparation method and application of a bis-schiff base based fluorescent sensing material and belongs to the technical field of chemical fluorescent sensing materials. 2,6-dihydroxymethyl phenol p-methyl phenol and thiosemicarbazide are adopted as basic raw materials, active manganese dioxide firstly serves as an oxidizing agent to oxidize the 2,6-dihydroxymethyl phenol p-methyl phenol into aldehyde, then glacial acetic acid is adopted as a catalyst to prepare the fluorescent sensing material through nucleophilic reaction and the thiosemicarbazide. The prepared material is based on symmetrical bis-schiff base, is stable in structure, and the water-soluble thiosemicarbazide is introduced to make the water solubility of the sensing material greatly enhanced. The prepared fluorescent sensing material has dual response, respectively has the sensitive selective recognition properties on Hg<2+> and Zn<2+>, shows different fluorescence emissions, is short in response time, is macroscopic under change of fluorescence signals of an ultraviolet lamp, and other common metal ion interferences are small.

The invention discloses a method for detecting stereisomer content of threo beta-hydroxy-alpha-amino acid. By adding dehydratase and Fe3+ to the system to be measured, and performing quantitative detection according to the absorption value of a specific ultraviolet wavelength to obtain threo-beta-hydroxy-alpha-amino acid in the system, the purpose of detecting the stereisomer content of beta-hydroxy-alpha-amino acid is achieved. The method, without using liquid chiral detection, can achieve the stereisomer detection of beta-hydroxy-alpha-amino acid high throughput.

The invention discloses a method for detecting related substances in flunarizine hydrochloride preparations. The test solution, control solution and impurity mixed solution are respectively taken for high-performance liquid chromatography detection, and each substance in the test product is detected at 210nm and 253nm respectively. Impurity content; where impurity A and 4,4-difluorobenzyl alcohol peaks were detected at 210nm, and the impurity content was calculated by the external standard method; other impurity peaks were detected at 253nm, and the impurity content was calculated by the self-control method. The method of the invention is easy to operate, has short analysis time, strong specificity and high sensitivity, and can effectively separate 7 impurities, including 2 process impurities and 5 degraded impurities. The separation between impurities and adjacent peaks can reach above 1.5.

The invention belongs to the technical field of analytical chemistry, and relates to a method for ratio-type electrochemical detection of nitrite ions, wherein the method comprises the steps: adding 50 [mu]L of a 10 mM o-phenylenediamine solution and 900 [mu]L of a 0.1 M acetate buffer solution into a 1 mL centrifuge tube, and uniformly shaking; respectively adding 50 [mu]L of NO2<-> with different concentrations, wherein the final concentrations in the system are respectively 10 [mu]M, 20 [mu]M, 50 [mu]M, 100 [mu]M, 200 [mu]M and 300 [mu]M; measuring the oxidation signal value of the mixed solution by using differential pulse voltammetry, recording the oxidation signal values of NO2<-> and OPD probes, and drawing a standard working curve by taking the concentration of NO2<-> as a horizontal coordinate and the ratio (INitrite / IOPD) of the NO2<-> and the OPD as a vertical coordinate; and determining oxidation signal values of a sample to be detected and the OPD probes in the mixed solution by using differential pulse voltammetry, and comparing the oxidation signal values with a standard working curve to obtain the concentration of NO2<->. The detection condition is mild, 10-300 [mu]M can be detected, the detection limit is as low as 4.7 [mu]M, and high-sensitivity, high-accuracy, high-selectivity and low-cost detection of nitrite ions in the environment and food is achieved.

The invention belongs to the technical field of chemical fluorescent sensing materials, relates to a preparation method and use of a coumarin derivative-based fluorescent sensing material, and provides a coumarin derivative-based fluorescent sensing material. The material is a fluorescent chemical sensing material prepared by taking 7-hydroxycoumarin and levulinic acid as basic raw materials, taking dichloromethane as a solvent, adding N,N-diisopropylcarbodiimide to remove water molecules from the carboxyl of the levulinic acid to turn the levulinic acid into acid anhydride, adding 4-methylaminopyridine to neutralize the excessive levulinic acid and performing nucleophilic reaction. The prepared fluorescent sensing material is high in water solubility and biocompatibility and quick in response, and has sensitive selective recognition performance for SO3<2->, changes in fluorescence signals are visible to eyes under an ultraviolet lamp, the interference of other common anions is little, and target ions in a biological cell are successfully imaged.

The invention relates to a method for detecting fosfomycin sodium in pharmaceutical wastewater by ion chromatography, the method comprising the following steps: (1) Chromatographic conditions: the chromatographic column is a low-capacity hydroxide system cathodic protection column and a high-capacity anion exchange separation Column, suppressor adopts electrolytic membrane suppressor, conductivity detector, eluent is potassium salt solution; (2) to the preparation of standard solution: get the standard product of fosfomycin sodium and configure it into standard product solution with ultrapure water; (3) Pretreatment of the sample: the sample used for detection is filtered with a 0.45 μm filter membrane and then passed through a C18 small column to remove organic matter in the water sample; (4) Determination method: inject the standard solution into the ion chromatograph, record the spectrum, Determine the position of the standard peak, calculate the area of ​​the fosfomycin sodium peak, draw a standard curve according to the calculated peak area; take the test sample, inject it into an ion chromatograph, record the spectrum, and calculate the concentration of the sample according to the area of ​​the fosfomycin sodium peak. The invention has the advantages of good reproducibility, low detection limit, high sensitivity, simple operation, mild detection conditions, wide application of detection equipment and instruments, wide sources of eluent potassium salt solution, and good detection of fosfomycin sodium in pharmaceutical wastewater. With the advantages of simple configuration, it will be widely used in the detection of fosfomycin sodium in industrial wastewater.

The invention belongs to the technical field of chemical fluorescence sensing materials, and relates to a preparation method and a use of a metal-responsive fluorescence sensing material. The metal-responsive fluorescence sensing material is prepared through a nucleophilic reaction of rhodamine hydrazide and 2-formyl thiazole which are used as base raw materials with methanol as a solvent and acetic acid as a catalyst. The fluorescence sensing material prepared in the invention has good water-solubility and biocompatibility, has a sensitive selective recognition effect on Fe<3+>, is slightly interfered by other common metal ions, and can be effectively complexed with the Fe<3+> to successfully realize the imaging of target ions in biological cells.

The invention discloses a mercury ion detection reagent as well as a preparation method and application thereof. The detection reagent is prepared from a gold nanoparticle solution and a dithiothreitol solution. The preparation method comprises the steps of adding the dithiothreitol solution into the gold nanoparticle solution, oscillating under the condition of keeping out of the sun, centrifuging and re-dissolving to obtain the detection reagent. The detection reagent provided by the invention has the advantages of being high in sensitivity, good in selectivity, strong in specificity and harmless to the environment, and the like; the detection reagent has a wide mercury ion detection range and is low in lower limit of detection, wherein the detection limit is 0.024mu M; the detection reagent can meet the standard limit value of the national standard; the preparation method of the detection reagent is simple in process and convenient to operate. The detection reagent provided by the invention can be used for qualitative and quantitative detection of the mercury ions, does not require special expensive instruments, has the advantages of being simple in process, convenient to operate, simple and rapid, mild in detection conditions, easy to control, low in cost, and the like, and has the advantages of high detection sensitivity, good detection selectivity, strong detection specificity and the like for the mercury ions, thus having very good use value and application prospect.

The invention belongs to the technical field of simulated enzymes and analytical chemistry, and relates to a colorimetric detection method for alkaline phosphatase activity based on sulfide-modified CoOx, comprising: adding alkaline phosphatase and 1 mM HMPi, reacted for 30-60 min; then added sulfide-modified CoOx suspension, TMB, H 2 o 2 and acetate buffer, mix the system and react for 1 to 30 min; after passing through the membrane, record the absorbance at a wavelength of 652 nm with a UV-visible absorption spectrophotometer; compare the absorbance measurement value of the above TMBox with the corresponding ALP activity Draw the calibrated ALP activity-absorbance standard working curve; repeat the above steps for the ALP sample to be tested, and compare it with the standard working curve to obtain the ALP activity. The detection process of the invention has mild conditions, does not require other reagents, realizes convenient and rapid detection of ALP activity, low detection cost, simple operation, wide detection range of 0.8-320 U / L, and realizes detection of alkaline phosphoric acid in human serum Detection of enzyme activity.

The invention relates to a preparation method and application of a hypochloric acid-responsive fluorescence sensing material, belonging to the technical field of chemiluminescence sensing materials. The hypochloric acid-responsive fluorescence sensing material provided by the invention is a chemiluminescence sensing material prepared through an electrophilic substitution reaction with coumarin-6-carboxylic acid and thiosemicarbazide as basic raw materials and absolute methanol as a solvent. The fluorescence sensing material prepared in the invention has good water-solubility and biocompatibility, is rapid in response, and can realize sensitive and selective recognition of OCl<->; the changes of fluorescence signals are visible to naked eyes under the illumination of an ultraviolet lamp; interference caused by other common negative ions and active oxygen substances is small; and the fluorescence sensing material successfully realizes imaging of target ions in biological cells.

The invention discloses a glutamic acid oxidase biosensor, a preparation method and an application thereof, and belongs to the technical field of electrochemical biosensors. The working electrode of this biosensor is made of PtNP@MXene‑Ti 3 C 2 T x solution, glutamate oxidase solution and chitosan solution modification, the preparation methods include: MXene‑Ti 3 C 2 T x The solution was mixed with chloroauric acid solution, sonicated and continuously reduced to obtain PtNP@MXene‑Ti 3 C 2 T x After the solution, it was drip-coated on the surface of the glassy carbon electrode, dried in a dust-free environment, and then modified with chitosan to glutamate oxidase on the surface, and refrigerated until completely dry. The enzyme biosensor of the invention can be used to detect the content of sodium glutamate (MSG) in food, and has high sensitivity, low detection limit and good anti-interference performance.

The invention belongs to the technical field of analytical chemistry, relates to an As <5 +> detection method, and specially relates to an As <5 +> colorimetric detection method based on iron alkoxidenano-enzyme. The method comprises the following steps: preparing 1 mg.mL <-1 > of an iron alkoxide nano-enzyme solution from deionized water, respectively dispersing 100 [mu] L of the iron alkoxide nano-enzyme solution in 2700 [mu] L of an acetic acid-acetate buffer solution, adding 100 [mu] L of As <5 +> with different concentrations, and incubating for 0.5-5 min; respectively adding 100 [mu] Lof a 5 mM TMB ethanol solution, and incubating for 10-30 min; determining the ultraviolet absorption spectrum of the mixed solution by using an ultraviolet-visible absorption spectrophotometer, recording the absorbance at the wavelength of 652 nm, and drawing a standard working curve; repeating the steps to measure the absorbance of the As <5 +> sample to be measured; and comparing with a standardworking curve to obtain the As5 + concentration. According to the invention, As <5 +> is detected by iron alkoxide nano-enzyme colorimetry, the conditions in the detection process are mild, so convenient and rapid detection of As < 5 + > is realized, and the cost is low; the detection range is as wide as 3.33-333.33 [mu] g.L <-1 >, and the lowest limit of the World Health Organization on arsenicions is met.

The invention discloses a biological tissue mass spectrometry imaging method, comprising the following steps: (1) selecting isolated mouse kidney tissue, freezing and slicing to obtain mouse kidney tissue slices; Obtained mouse kidney tissue slices adhered to the corundum rods, and air-dried naturally; (3) dripping acriflavine solution on the mouse kidney tissue slices, and let it stand to spread evenly; (4) the adhered The corundum rods of mouse kidney tissue slices dripped with acriflavine solution were placed in a mass spectrometer with a laser for detection, and the mass spectrometry data ionized after laser analysis were processed by software to obtain mouse kidneys containing acriflavine Mass spectrometry imaging of tissue. The method is fast and direct, can avoid matrix interference and has no complicated sample pretreatment process, and the ionization imaging technology after laser analysis can adjust the mass spectrometry signal in time and space, which is conducive to optimizing the mass spectrometry imaging map.