127results about How to "Sensitive assay" patented technology

The invention provides a kit for detecting gastrin-17 and a preparation method as well as application thereof. The kit comprises components A and B, wherein the component A is a first anti-gastrin-17 antibody marked with a tracing marker or coated with a magnetic ball, and the component B is a second anti-gastrin-17 antibody coated with the magnetic ball or marked with the tracing marker, or the gastrin-17; moreover, any one of the components A and B is marked with the tracing marker, the other one is coated with the magnetic ball; and the first anti-gastrin-17 antibody and the second anti-gastrin-17 antibody have different binding sites with the gastrin-17. The invention provides a method for detecting the gastrin-17, with the kit provided by the invention, content of the gastrin-17 in a sample can be detected accurately and sensitively according to a double antibody sandwich method principle or a competition method principle.

The invention discloses a determination method of a serum metabolic marker for early diagnosis of diabetic nephropathy. The method mainly utilizes analysis technique and method such as gas mass spectrometry and mass liquid spectrometry for quantitative determination of endogenous small molecule compounds in urine of patients with diabetes and diabetic nephropathy; and relative concentration difference between endogenous small molecule compounds in a pathological group and a normal group is calculated and compared, so as to be applied to clinical early diagnosis of diabetic nephropathy. Compared with other existing clinical diagnosis indexes, the method has advantages of wide adaptation range, sensitivity, simple sampling and operation, and no harm on the body. The method is more suitable for screening of diabetic nephropathy in early stage with some uncertain physiological and biochemical indexes, so as to avoid missing of the best treatment time due to delayed diagnosis.

A method for measuring the content of melamine in a liquid sample uses a portable Raman spectrometer (SERS) based on gold nano-particle substrates to measure Raman spectrum for the liquid sample through pretreatment. The method for measuring the content of melamine in a liquid sample in the invention is convenient, sensitive, quick and practical, has simple pretreatment, quick (including pretreatment and detection and being finished in 30min, particularly capable of being finished in 2min in Raman enhanced spectrum detection) and sensitive measurement, and is applicable to field high-flux detection; and the method is portable, needs few consumption of sample, and can be qualitative and quantitative.

A detection method simultaneously detects residue of multiple synthetic antibacterial agents in aquatic products by a high performance liquid chromatography. The synthetic antibacterial agents mainly comprise sulfadiazine SD, sulfamerazine SMR, sulfadimidine SDD, sulfadimethoxine SDM, furazolidone FZD, oxolinic acid OXA, nalidixic acid NAA and the like. The multiple synthetic antibacterial agents in an aquatic product sample are extracted by acetonitrile, degreased by normal hexane, concentrated, purified by a solid phase extraction column (alumina neutral) or a C18 solid phase extraction column, analyzed by a liquid chromatograph, detected by an ultraviolet detector, and quantified by an external standard method. The method can quickly, sensitively and accurately detect multiple target compounds to greatly reduce detection cost and shorten detection time.

The invention discloses an ELISA method by indirect competition for testing the cadmium ion, which is to add the extracting solution of the seafood samples and the standard fluid of cadmium ion in serial consistency into the millipore of the antigen pre-peridium strips, and then add the monoclonal antibody with the function of anti-cadmium ion into each millipore, blend for incubation, add the antibody with the function of anti-mouse IgG marked by HRP and then make incubation; stop the reaction after the substrate chromogenic cadmium ion, test the absorbency of each millipore by enzyme mark instrument, and calculate the contact in the samples in accordance with the curvilinear regression equation gained from the standard control. By utilizing the gained secretory positive cells of the monoclonal antibody with the function of anti-cadmium ion, the method provided in the invention can prepare in mass production the monoclonal antibody with the function of anti-cadmium ion. The method costs low, which can fast, simply and sensitively test the content of the cadmium ion in the samples. The invention can make fast and sensitive test on the heavy metal cadmium left in the seafood like fishes and shellfishes on a large scale.

The invention relates to a method for detecting a trace amount of acephate in a sample and provides a kit. According to a dopamine oxidation polymerization method, an artificial antibody namely an MIP (molecularly imprinted polymer) which can be specifically bonded with the acephate is synthesized on a carrier material; after a trace amount of acephate enriched in different samples is specifically separated by using the MIP, the content of the enriched acephate is determined according to an enzyme inhibition-chemiluminescence method. The MIP is high in temperature resistance and organic solvent resistance, the trace amount of acephate enriched in the different samples can be directly and specifically separated through the MIP, and the influence of various interference matters such as other organophosphorus pesticides and chlorophyll is removed. An MIP specific sample pretreatment method is organically combined with an enzyme inhibition method into an MIP-enzyme inhibition method, so that a certain pesticide can be specifically and quickly detected by the enzyme inhibition method, the detection sensitivity and the detection specificity can be improved, and a trace amount of target pesticides in environment and food can be directly, quickly and sensitively detected with high throughput.

The invention provides a fluorescence probe for identifying cupric ions under an alkaline condition and a preparation method and application of the fluorescence probe, and mainly solves the problem that an existing fluorescence probe cannot quantificationally detect the cupric ions under a strongly basic condition while serving as a basic indicator. The fluorescence probe is a covalent combinationof 2-(2-hydroxyphenyl)benzothiazole and salicylhydrazide. The method comprises the steps that 1, 3-methylsalicylaldehyde and o-aminobenzenethiol react to obtain a compound 1; 2, the compound 1 obtained in step 1 reacts with urotropine to obtain a compound 2; 3, the compound 2 obtained in step 2 reacts with the salicylhydrazide to obtain a target compound Z. The fluorescence probe is used for thesensing detection of the content of the cupric ions under the strongly basic condition, and is used for the detection of pH values as a weakly basic indicator. The invention belongs to the field of fluorescence probes.

The invention discloses a method for determining a serous metabolic biomarker of a heroin abuse crowd, which is implemented mainly through that by using analysis techniques and methods based on gas chromatography/mass spectrum and liquid chromatography-mass spectrum and the like, endogenous small molecular compounds are quantitatively determined, and by calculating and comparing the relative concentration difference between the endogenous small molecule compounds of a heroin abuse crowd and a healthy crowd, the metabolic biomarker concentration ranges of the two sets of crowds are respectively determined; and the method is applied to the clinical identification of heroin abuse crowds. Compared with the existing other identification methods, the method is wide in adaptive range, sensitive, convenient for sampling, and simple in operation, and has no harm to the body. The method solves the problem of the absence of clinical indicators for heroin abuse clinically, and facilitates the identification of clinical heroin abusers and the improvement of identification accuracy.

The invention provides a method for determining content of impurities in a linagliptin raw material. The method comprises the steps as follows: analyzing the linagliptin raw material with HPLC (high performance liquid chromatography) to obtain a chromatogram; determining the content of impurities in the linagliptin raw material on the basis of the chromatogram, wherein the HPLC adopts the following conditions: a chromatographic column is a chromatographic column YMC-PACK ODS-AM with the specification of 4.6*250 mm and 5 mu m, a detector is (diode array detector) DAD, the detection wavelength is 226 nm, the column temperature is 25 DEG C, a mobile phase A is a 10 mmol/L potassium dihydrogen phosphate buffer solution with the pH in a range of 3.0-5.0, a mobile phase B is acetonitrile, the flow speed is 1.0 mL/min, operation lasts for 10 min, and the elution gradient is shown in the description. With the adoption of the detection method, the content of impurities in the linagliptin raw material can be determined conveniently, accurately and sensitively, so that the quality of the linagliptin raw material can be effectively controlled.

A reinforcement bar corrosion pH critical value determining method relates to a determination of a pH critical value. The invention provides a reinforcement bar corrosion pH critical value determining method which dips the reinforcement bar in absolute ethyl alcohol for being washed by ultrasonic and wiped up after burnishing and cleaning the electrode surface of the reinforcement bar; arranges the electrode of the reinforcement bar into an electrolytic cell and mounts a scanning microelectrode as well as a micro-reference electrode for forming an electrolytic cell used for determining the potential distribution on the surface of the reinforcement bar and confirming the reinforcement bar corrosion pH critical value; arranges the electrolytic cell in a scanning microelectrode measuring system; mounts simulated concrete hole liquid in the electrolytic cell, calculates the time of the electrode of reinforcement bar to be dipped in the simulated concrete hole liquid and uses water for regulating the pH value of the simulated concrete hole liquid to be 10.00 to 12.50 and reviews reinforcement bar corrosion behavior by respectively determining the potential distribution at the micro-areas on the surface in the simulated concrete hole liquid of the electrode of the reinforcement bar with various pH values and confirms the pH critical value causing the reinforcement bar corrosion by adopting a successive approximation method.

A low-temperature formaldehyde catalytic illumination sensitive material is a Pd-atom-doped composite powder composed of CoO, TiO2 and Al2O3. A preparation method includes the following steps: 1) co-dissolving cobalt salt, titanium salt and aluminum salt in a hydrochloric acid water solution and adding citric acid, dropwise adding ammonia water to regulate pH value, aging the mixture, performing spin-evaporation to prepare a gel, drying and grinding the gel, and roasting the gel in a chamber electric resistance furnace to obtain a powder mixture; 2) adding hydrazine hydrate to a PdCl2 solutionto reduce the PdCl2, adding the product to the powder mixture in the step 1), drying the mixture, performing two-stage calcination in a tubular furnace under vacuum, and naturally cooling the productto room temperature under protection of argon gas to obtain the Pd-atom-doped composite powder composed of CoO, TiO2 and Al2O3. The sensitive material can be used for producing a gas sensor, which can quickly test formaldehyde in air in trace amount at use temperature of not more than 200 DEG C without influence due to other common coexisting substances.

The invention discloses a high performance liquid chromatography (HPLA) method for measuring content of hypocrellin A. The conditions of the liquid chromatography are as follows: octadecylsilane chemically bonded silica is used as a filler for a chromatographic column, and a mobile phase is a mixed solvent consisting of methanol and dilute phosphoric acid (or dilute formic acid, dilute acetic acid and dilute sulfuric acid), wherein the volume ratio of the methanol and the dilute phosphoric acid (or dilute formic acid, dilute acetic acid and dilute sulfuric acid) is 80:20-70:30, and the detection wavelength is 462 nm. The invention overcomes the defects of traditional analysis method and can be directly applied to the quantitative analysis of hypocrellin A in traditional Chinese medicine and preparation including the hypocrellin A. The method has the technical characteristics of good separation effect, precise measurement, sensitivity, strong specificity, fast measurement and the like. The absorption peak of the hypocrellin A in the medicine and preparation including the hypocrellin A can fully flow out the chromatographic column within 30 minutes, and the analysis work is finished.

The invention belongs to the field of medical detection and discloses a chemiluminescence assay kit for detecting C-peptide content in serum and a detection method. The assay kit comprises: an M reagent, an R reagent, a C-P calibrator, a pH adjuster, a reaction enhancer, and a chemiluminescent substrate. The M reagent contains a magnetic particle coated with a C peptide-biotinylated antibody at aconcentration of 2[mu]g/mL, and a Tris buffer solution at a concentration of 0.2mol/L. The R reagent contains a C-P-AP labeled antibody at a concentration of 1[mu]g/mL, and a Tris buffer solution at aconcentration of 0.1mol/L. The C-P calibrator comprises two different concentrations of C-peptide samples and a 0.1mol/L concentration of Tris buffer solution. The assay kit for detecting C-peptide has advantages of strong specificity and good stability, thereby improving the sensitivity and specificity of the detection; has a good stability in the whole system; is simple in operation; and is suitable for use with a clinical full automatic chemiluminescence assay instrument.

The present invention relates to ionic chromatography method of detecting glyoxalic acid, glycolic acid, glyoxal and oxalic acid. The detection includes the steps of: weighing sodium carbonate and sodium bicarbonate and dissolving with deionized water to compound eluting liquid; weighing sodium hydroxide and dissolving with deionized water to compound eluting liquid; weighing sodium hydroxide and dissolving with deionized water to compound eluting liquid; diluting the sample with deionized water to concentration for detection and ionic chromatography detection; comparing the ionic chromatography detection result of the sample with corresponding standard work curve to obtain the composition and contents of the sample. The said method can fast detecting the said components simultaneously in high selectivity and high sensitivity.

The invention discloses a method for detecting cyanine in textile through reversed-phase high-efficiency liquid chromatography. The method comprises the following steps: (1) a solution of a sample to be detected is prepared; (2) a standard solution is prepared; (3) the standard solution is taken out, is injected to a high-efficiency liquid chromatographic instrument and is mensurated through a reversed-phase high-efficiency liquid chromatography method; the peak-out position of the cyanine is mensurated by a liquid chromatography-mass spectrometry instrument; the peak-out area is recorded; with concentration as an abscissa and the peak-out area as an ordinate, a standard curve equation is manufactured; and (4) according to the method in step (3), the cyanine and the peak-out area in the solution of the sample to be detected are mensurated; and the obtained standard curve is used to obtain the content of the cyanine in the sample to be detected through calculation. The method can accurately, reliably and sensitively mensurate the cyanine and the content of the cyanine in the textile.

The invention discloses a cherry tomato freezing point determination method. According to the invention, high-grade cherry tomatoes are purchased, selected, and grouped; geometrical centers of the cherry tomatoes are determined; temperature thermocouples are scaled; the thermocouples are arranged at the geometrical centers; a thermocouple Fluke-NetDAQ32 data acquisition apparatus is connected with a computer; the computer and the thermocouple Fluke-NetDAQ32 data acquisition apparatus are started; the cherry tomatoes with the fixed thermocouples are positioned in a freezing compartment of a refrigerator; temperature variations are recorded every 0.5 to 1s; when the temperatures of the thermocouples are -5 to -10 DEG C, temperature measuring is stopped; a cooling curve is drawn according to the acquired temperature data, such that freezing points are determined; abnormal points are pointed out, the freezing point of the cherry tomatoes is calculated according to an arithmetic average method, and a freezing temperature range is determined. The method provided by the invention is advantaged in simple operation, convenient operation, high speed, and relatively high accuracy.

The invention discloses a method for measuring a storage temperature range of grapes. The method comprises buying superior-grade grapes, selecting, sorting, and determining a geometric center of the grapes; marking a temperature testing thermocouple; arranging the thermocouple at the geometric center; connecting the thermocouple Fluke-NetDAQ32 data acquisition instrument with a computer; powering on the computer and the data acquisition Fluke-NetDAQ32; putting the grapes fixed with the thermocouple in a refrigerating chamber of a refrigerator; recording the temperature change every 0.5-1s; drawing a temperature dropping curve according to the acquired temperature data so as to determine an ice point and an overcooling point; and finally determining the overcooling storage of the grapes within the temperature between the ice point and the overcooling point. The testing method has the beneficial effects of being simple, convenient and rapid to operate and high in accuracy.

The invention provides a measurement method for concentration of bisphenol S, and relates to the technical field of chemical analysis and detection. The measurement method comprises the following steps of S1, preparing a blank solution through a sulfuric acid solution, a Fenton reagent and a fluorescent probe solution; S2, preparing multiple standard working solutions through the sulfuric acid solution, the Fenton reagent, the fluorescent probe solution and bisphenol S standard solutions in different concentrations; S3, respectively measuring optical indexes of the blank solution and multiplestandard working solutions, and building a standard curve according to the optical indexes and the concentration of the bisphenol S in the multiple standard working solutions; and S4, measuring an optical index of a to-be-measured sample, and obtaining the concentration of the bisphenol S in a to-be-measured sample according to the optical indexes of the to-be-measured sample and the standard curve. With the measurement method for the concentration of the bisphenol S, provided by the invention, the concentration of the bisphenol S can be rapidly and sensitively measured according to the structure characteristic of sulfuryl contained in the bisphenol and the oxidization characteristics of the Fenton reagent.

The invention discloses a low-temperature catalytic luminescence sensitive material for benzene. The low-temperature catalytic luminescence sensitive material for benzene is characterized by being a composite powder material comprising Pt atom doped MoO3, WO3 and Al2O3, wherein the mass percentages of the components are 1.6 to 2.2% of Pt, 26 to 30% of MoO3, 36 to 42% of WO3 and 27 to 31% of Al2O3,and the preparation method of the low-temperature catalytic luminescence sensitive material comprises the following steps: dissolving tungsten salt in a hydrochloric acid aqueous solution, dissolvingaluminum salt in a citric acid aqueous solution, adding agar powder after mixing the hydrochloric acid aqueous solution with the citric acid aqueous solution, then dissolving ammonium molybdate crystals into the solution, adding glucose and chloroplatinic acid, performing reflux, cooling, forming a gel, drying the gel, calcining, and naturally cooling to obtain the sensitive material. A gas sensor made from the sensitive material provided by the invention can rapidly determine trace benzene in air at the working temperature not exceeding 200 DEG C without interference from other common coexisting substances.