59results about How to "Strong anti-matrix interference ability" patented technology

The invention relates to a method for detection of 25-hydroxyvitamin D in serum. The method comprises sample pretreatment: adding an acetonitrile solution containing a 25-hydroxyvitamin D internal standard substance into a serum sample, carrying out protein precipitation, carrying out centrifugation, taking the supernatant and diluting the supernatant through acetonitrile to obtain a sample to be detected, wherein a volume ratio of the serum sample to the acetonitrile solution is 1: 1-4 and a volume ratio of the supernatant to acetonitrile is 1: 1-4, and enrichment, separation and detection: carrying out enrichment, separation and detection on the sample to be detected through a two-dimensional liquid chromatography-tandem quadrupole mass spectrometer. The method is simple, greatly shortens the detection time, improves the detection flux of the sample and has a high detection precision, a low cost, specificity and strong matrix interference resistance.

The invention relates to a method for screening single chain antibodies of Microcystin-LR and verification thereof. The method comprises the following steps: carrying out two rounds of affinity screening on the biotinylated Microcystin-LR in a human source synthetic antibody library by using an avidin labeled magnetic bead and a negative screening method; extracting total plasmid DNA from phage colonies produced in the second round, carrying out enzyme digestion with enzyme Sfi I, recycling gel to obtain single chain antibody genes, connecting the single chain antibody genes with soluble expression carrier pAK100CL which is processed by enzyme digestion in the same way, and electrically transforming the connected carrier into colibacillus XL1-Blue to obtain soluble expression single chain antibodies; and verifying the soluble expression single chain antibodies by using a competitive time-resolved fluorescence immune analytical method. The invention has the advantage of quick, simple and convenient screening, and can well expose the Microcystin-LR three-dimensional structure into the incubation system. The verification on the screening result has the advantages of high detection signal and strong anti-interference capacity against stroma.

The invention discloses a trace copper ion visual rapid detection method. High sensitivity visual rapid detection of Cu<2+> is realized by using a rhodamine B spiro lactam derivative as a Cu<2+> identification probe and combining Fe3O4 magnetic nanoparticles. According to the invention, visual rapid detection of trace Cu<2+> is realized by utilizing the characteristics that the rhodamine B spiro lactam derivative modified on the magnetic nanoparticles can be specially combined with copper ions and changes color (from faint yellow to pink purple) and utilizing the enrichment of the magnetic nanoparticles. The trace copper ion visual rapid detection method has the characteristics of speediness, simplicity, high sensitivity, visualization, high specificity, low cost and the like, and can be used for visual rapid detection of trace copper ions in various water environment samples.

The invention belongs to the technical field of physical and chemical inspection of food additive residues in tobacco essences, and particularly relates to a method for detecting five sweetening agents in a tobacco essence through the ultra-high performance liquid chromatography-tandem mass spectrometry. The method is characterized by comprising the following steps that the tobacco essence is weighed, then ultrapure water is added, then oscillating extraction is carried out, extract liquid is purified and filtered and is diluted by using the ultra-pure water, and then the sweetening agents inthe tobacco essence are directly detected through the ultra-high performance liquid chromatography-tandem mass spectrometry. The method has the advantages of being capable of rapidly and accurately detecting the residual quantity of the sweetening agents in the tobacco essence, environmentally friendly, accurate in result, less in interference, high in sensitivity and good in repeatability.

The invention relates to a method for detecting mercury ion residue of a fluorescent signal conversion mechanism based on a nucleic acid aptamer structure. In the method, a mercury ion nucleic acid aptamer marked with a fluorescein molecule, and a complementary sequence marked with a quenching element are utilized to form a fluorescent detection system, wherein the mercury ion nucleic acid aptamer is a stem loop structure composed of 27-28 bases and owns a stem formed by covalent binding of the bases GGAC and GTCC; and the base sequence of the complementary sequence Q2 is shown in SEQ ID NO.1. The method for detecting the mercury ion residue by the fluorescent detection system comprises the following steps of: adding mercury ions with a serial concentration and a complementary sequence Q2 competitive binding nucleic acid aptamer; establishing a standard curve according to the change of fluorescent signals and determining the lowest detection limit and linear range; and then, carrying out marking detection on a sample to be detected and judging the content of the mercury ions in the sample according to the standard curve. The method disclosed by the invention has the advantages of rapidness, simplicity, high sensitivity and selectivity and less sample quantity demand, and is applicable to the detection of the mercury ions in the actual sample.

The invention belongs to the technical field of physical and chemical inspection for food additive residues in electronic cigarette liquor and specifically relates to a method for detecting five sweetening agents in electronic cigarette liquor through ultra-high performance liquid chromatography-tandem mass spectrum. The method is characterized by comprising the following steps: first, weighting the electronic cigarette liquor, and then adding ultrapure water for diluting, and at last, determining the sweetening agents in the electronic cigarette liquor through ultra-high performance liquid chromatography-tandem mass spectrum. According to the method, the sweetening agent residues in electronic cigarette liquor can be quickly and accurately detected. The invention has the advantages of environment-friendly method, accurate result, little interference, high sensitivity and good repeatability.

The invention discloses a biological sensing chip capable of circularly detecting trace uranyl ions and a preparation method and application method of the chip. The chip consists of a ZnO-Ag compositematerial substrate, a nucleotide sequence and sequence fragments of a 5'-end coupled sulfhydryl group and a 3'-end coupled fluorescent dye RhB. The chip is composed of a composite material and a biological sensing probe, DNAzyme covalently connected to the chip can achieve specific response to uranyl ions, and the biological activity is activated, so that a substrate chain is broken into two freeDNA sections to modify fluorescent molecules on one DNA section; since the DNA sequence is broken and DNAs fall onto the surface of an SERS substrate, stronger SERS signals can be detected, and higher sensitivity, specificity and reproducibility can be achieved. Meanwhile, by repairing the broken sequence, the biological sensing probe can be circularly used to achieve the purposes of high-efficiency detection and cost reduction.

The invention provides a detection method and a kit for detecting 25-hydroxyvitamin D (25OHD) in human serum. The method comprises the following steps: mixing a serum sample with a sodium hydroxide aqueous solution uniformly; performing ultrafiltration centrifugation; adding an isotope internal standard solution of 25-hydroxyvitamin D in the ultrafiltrate; after full and uniform mixing, adding a methyl tertiary butyl ether solvent and carrying out vortex shock extraction; after centrifugation, taking a supernatant and carrying out nitrogen drying, and carrying out redissolving to obtain a to-be-measured sample; and then carrying out detection. The detection method has advantages of simple pre treatment, high specificity and resistance to matrix interference, high detection precision and accuracy, and high detection sensitivity.

This inventio discloses a method for determining major sweetening agents in an edible essence and flavor by HPLC-MS / MS. The method comprises the steps of preparing a matrix solvent, preparing a seriesof standard working solutions, preparing a sample solution, performing HPLC-MS / MS analysis, building a standard work curve, and performing sample result calculation. According to the method, curves are prepared and corrected by the matrix solvent for the first time; and an HPLC-MS / MS chromatograph is used for simultaneously determining nine kinds of major sweetening agents such as xylitol, acesulfame potassium, saccharin sodium, sodium cyclamate, sucralose, aspartame, neohesperidin, neotame and stevioside in edible essence. The method has the advantages that the proper matrix solvent is prepared, and is used for preparing a standard work curve; the influence caused by matrix effects on the quantification of target materials in the mass spectrometry ionization process is eliminated; the contents of the major sweetening agents in the edible essence can be simultaneously detected; the result is accurate; the interference is little; the sensitivity is high; and the repeatability is high,and the like.

The invention discloses a method for rapidly detecting ethyl carbamate in baijiu based on ultra-high performance liquid chromatography combined with high resolution mass spectrometry, and belongs to the technical field of detection and screening of risky substances in fermented food. The method includes the following steps: performing concentration and redissolution pretreatment on a white spirit sample, and extracting and enriching a target to-be-detected substance in the white spirit sample to obtain a target to-be-detected substance sample; detecting the obtained target to-be-detected object sample based on an ultra-high performance liquid chromatography-high resolution mass spectrometry technology to obtain a primary mass spectrum and a secondary mass spectrum of the target to-be-detected object sample; and extracting target object information through software based on the obtained primary and secondary mass spectrograms, establishing a standard spectrogram based on an ethyl carbamate standard substance, comparing the established standard spectrogram with the obtained extracted target object information, and carrying out qualitative and quantitative determination on ethyl carbamate in the white spirit sample. Thus, the high-sensitivity and high-accuracy systematic detection method for the food safety risk ethyl carbamate in the white spirit is established.

The invention provides a method for analyzing sucrose ester in tobacco through multi-dimensional liquid chromatography-mass spectrometry. The method comprises the steps of adding an internal standardsample into a tobacco sample, adding a solvent, extracting, centrifuging and filtering to obtain a sample solution; and then, measuring the sample solution by adopting a two-dimensional liquid chromatography-mass spectrometry combination method, qualitatively determining the sucrose ester component and the internal standard sample in the sample solution by mass spectrometry, quantitatively determining the internal standard sample in the sample solution through a standard curve method, and determining the relative content of the sucrose ester component with the structure similar to that of theinternal standard sample determined quantitatively in the sample solution. The invention further provides a multi-dimensional liquid chromatography-mass spectrometry combined analysis system and a using method thereof. The method for analyzing the sucrose ester in the tobacco by the multi-dimensional liquid chromatography-mass spectrometry can effectively remove interfering substances which influence the quantification of the sucrose ester in the tobacco, has the characteristics of being high in accuracy, good in reproducibility and low in detection limit, the analysis can be automatically accomplished through an instrument, and the method is suitable for the batch detection of the tobacco sample.

The invention provides a method for determining total fluorine compound precursor substances in an atmospheric particulate matter sampling filter membrane; the method comprises the following steps of1) extracting a sample: carrying out ultrasonic extraction on the atmospheric particulate matter sampling filter membrane, and collecting to obtain an extracting solution; 2) purification of the sample: carrying out purifying, concentrating and purifying on the extracting solution obtained in the step 1) to obtain a sample detection solution; and 3) determination of the sample: detecting the sample detection solution obtained in the step 2) by adopting an ultra-high performance liquid phase chromatography-triple quadrupole series mass spectrometer, and obtaining the content of the total fluorine compound precursor substance by adopting an internal standard method. The invention belongs to the technical field of environmental monitoring, and by virtue of the provided measurement method, full extraction and measurement of six kinds of total fluorine compound precursor substances, such as 4:2FTS and the like in the atmospheric particulate matter sampling filter membrane can be realized, the separation effect is good, and the detection efficiency is improved; and the method has the advantages of being accurate in measurement result, high in repeatability, high in sensitivity, high in recovery rate, low in detection limit, high in substrate interference resistance and the like.

The invention relates to a method for detecting dimethachlon residue in tobacco by an competition-indirect time-resolved fluoroimmunoassay system, wherein the CI-TRFIA (competition-indirect time-resolved fluoroimmunoassay) system takes dimethachlon-OVA as a coating antigen, a dimethachlon polyclonal antibody as a recognition antibody and a Goat Anti-rabbit IgG (immunoglobulin G) marked with Eu-N1 as a secondary antibody to establish a standard inhibition curve corresponding to dimethachlon pesticide; and the detection of the dimethachlon residue in tobacco is realized by the following steps: after pretreatment on a tobacco sample, detecting the tobacco sample by the CI-TRFIA system and then judging the quantity of the dimethachlon residue in the tobacco corresponding to the sample.

The invention discloses a method for detecting insect in-vivo juvenile hormone JH II based on chromatography-mass spectrometry and relates to application of analytical chemistry in entomology research. The method comprises the specific steps that an insect sample is taken, grinding balls, acetonitrile, a sodium chloride water solution and normal hexane are added for grinding, high-speed centrifugation is performed to obtain a normal-hexane-layer crude extract, then normal hexane is added to the sample for two times of grinding and extraction, the crude extract obtained through three times of grinding is added to a collecting bottle, and nitrogen blow-drying is performed; re-dissolution is performed with an acetonitrile-water solution, then the acetonitrile is eluted for three times by using a solid-phase extraction column, and eluant in a collecting box is taken out and subjected to nitrogen blow-drying; re-dissolution is performed with an acetonitrile-water solution, and analysis is performed by using a liquid chromatograph-mass spectrometer. The detecting method is high in sensitivity, strong in matrix interference resisting capability and good in repeatability and can provide help for research of in-vivo juvenile hormone JH II change laws of insects at all stages.

The invention belongs to the technical field of detection of organic mercury in a water environment and water products and particularly relates to a method for visually and rapidly detecting an organic mercury compound. The method comprises the following steps: firstly, sufficiently and uniformly mixing an HT9 DNA aptamer sequence with silver nitrate and organic mercury standard solutions with different concentrations respectively; secondly, separately and subsequently adding a Tris-HNO3 buffer solution, a NaBH4 solution and an HAuCl4 solution and then carrying out constant-temperature operation at the temperature of 95 DEG C for 10 minutes, and recording the color change of the solution by using a digital camera, and enabling the color change to correspond to the concentration of the organic mercury solution, thus establishing a standard color card; thirdly, operating to-be-tested liquid according to previous steps, recording the color of the solution by using the digital camera or observing the color of the solution with naked eyes, and comparing the color of the solution with the standard color card, thus realizing the semi-quantitative detection of the organic mercury in a water sample or an aquatic product extracting solution. The method has the advantages of simple operation, high detection speed (the whole detection process is completed within 2 hours), as well as low detection cost (the detection cost of a sample is lower than 2 yuan).

The invention discloses a measuring method of structural isomers of perfluorochemicals in an atmospheric particulate sampling membrane, and belongs to the technical field of environmental monitoring.The measuring method comprises the following steps of 1, sample extracting, wherein the atmospheric particulate sampling membrane is subjected to ultrasonic extraction, and thus an extraction solutionis collected and obtained; 2, sample purifying, wherein the extraction solution obtained in step 1 is purified, concentrated and repurified, and thus a sample detection solution is obtained; 3, sample measuring, wherein the sample detection solution obtained in step 2 is detected by an ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometer, quantitative calculation isconducted through an internal standard method, and thus the content of the structural isomers of the perfluorochemicals in the atmospheric particulate sampling membrane is obtained. By the adoption ofthe measuring method, the structural isomers of the perfluorochemicals in the atmospheric particulate sampling membrane are sufficiently extracted and measured.

The invention discloses a magnetic nano-material for pretreatment of trace drugs in sewage and a preparation and detection method, and relates to the technical field of trace drug detection, the magnetic nano-material is obtained by taking CoFe2O4 magnetic nano-particles as an inner core, and coating SiO2 and CTAB on the surface of the CoFe2O4 magnetic nano-particles in sequence; the method for detecting the trace drugs in the sewage comprises the following steps: by taking the magnetic nano material as an adsorbent, enriching and separating the drugs in a sewage sample by adopting a magnetic solid-phase extraction method, then analyzing the adsorbent, blow-drying the analyzed liquid nitrogen, and dropwise adding urchin-shaped nano Au-Ag sol to carry out in-situ SERS (Surface Enhanced Raman Scattering) detection. The invention establishes a pretreatment and detection method for drugs in sewage, and the method has the advantages of simple operation, rapidness, high sensitivity, strong matrix interference resistance, no need of tedious operations such as use of a large amount of organic reagents, centrifugal filtration and the like, low cost and capability of meeting the detection requirements of trace drugs in sewage.

The invention relates to a method for enriching and extracting three heavy metal ions in a shellfish sample and simultaneously determining the content of the three heavy metal ions, and specifically relates to preparation of an ionic liquid coated amino silanization magnetic graphene oxide (MGO (at) SiO2-APTES-IL) nano composite material and application of the nano composite material in detectionof three target heavy metals in a shellfish sample. According to the method, MGO (at) SiO2-APTES-IL is adopted as an adsorbent, the shellfish sample is pretreated by adopting dispersive magnetic solid-phase microextraction (d-MSPE), and target heavy metals including lead (II), copper (II) and cadmium (II) are sensitively determined by taking inductively coupled plasma mass spectrometry (ICP-MS) asa detection tool; the composite material can extract and enrich trace target heavy metal elements under the interference of the sample matrix, and still shows good adsorption performance in multipletimes of cyclic utilization. According to the method, main influence factors influencing adsorption and desorption of the target heavy metal ions are researched and optimized, experimental results meet the requirements for high sensitivity and high accuracy, and a new method is provided for detection of the three target ions in shellfish.

The invention belongs to the technical field of physical and chemical inspection of harmful substance residues in paper for cigarettes and in particular relates to a determination method for detecting a fat-soluble coloring agent in the paper for cigarettes; the determination method is characterized by comprising the following steps: firstly, shearing the paper for cigarettes; carrying out ultrasonic extraction; after carrying out extraction and purification on a dispersed solid phase of an extracting solution and centrifuging, directly filtering and determining the fat-soluble coloring agent in paper sheets by utilizing an ultra-performance liquid chromatography-tandem mass spectrometry. The method provided by the invention can be used for rapidly and accurately detecting the residues of the fat-soluble coloring agent in the paper for cigarettes; the method has the advantages of environment protection, accurate result, few interferences, high sensitivity and good repeatability.

The invention provides a method for measuring benzoic acid and sorbic acid through hollow fiber microextraction combining online derivatization-gas chromatography. The pre-treatment extraction steps are less, the enrichment coefficient is high, the cost is low, the using amount of organic solvents is low, the method has the very good sample purification capability, and meanwhile, has the higher anti-matrix interference ability. In addition, the hollow fiber is low in cost, can be used disposably, and cross contamination among samples can be avoided.

The invention discloses a method for determining N-dimethyl nitrosamine in water, which is based on a dispersive solid-phase extraction principle, and comprises the following steps: mixing coconut shell activated carbon powder with a water sample, carrying out ultrasonic-assisted dispersion to complete extraction, and carrying out negative-pressure quick suction filtration and elution and then, adding acidic ionic liquid during rotary evaporation, so that volatilization and loss of N-dimethyl nitrosamine in the rotary evaporation process can be reduced. Compared with a traditional solid-phaseextraction method, the time required for analysis is greatly shortened on the premise that the detection sensitivity and the result reliability are guaranteed. Meanwhile, the invention also provides acorresponding on-site sampling kit which is matched with a suction filter and a small ultrasonic instrument to realize on-site sampling, treatment and storage of the water sample, and subsequently, the pretreatment sample solution only needs to be brought back to a laboratory to be concentrated for detection.

The invention belongs to the research fields of plant growth and development, molecular heredity, cytobiology and the like, and relates to a plant hormone quantitative detection kit, a detection method and application. The plant hormone quantitative detection kit is used for accurately and quantitatively detecting 10 plant hormones in a plant sample. The plant hormone quantitative detection kit disclosed by the invention is small in required sample volume, simple in sample pretreatment, strong in specificity and matrix interference resistance, short in detection time, high in flux, high in detection precision and low in cost. The invention also discloses a method for quantitatively detecting plant hormones by using the kit.

The invention belongs to the technical field of physical and chemical inspection of harmful substance residues in cigarette paper and particularly relates to a determination method for detecting 14 disabled colorants in cigarette paper by ultra-performance liquid chromatography-tandem mass spectrometry. The determination method is characterized by comprising the following steps: firstly, cutting up the cigarette paper and then adding ethanol; secondly, carrying out ultrasonic extraction, centrifuging an extracting solution, then filtering, diluting with acetonitrile, and directly determining the disabled colorants in the paper by the ultra-performance liquid chromatography-tandem mass spectrometry. By means of the method, residual quantity of the disabled colorants in the paper can be detected quickly and accurately; and the method has the advantages of environmental protection, accurate results, less interference, high sensitivity and high repeatability.

The invention provides a determination method of pesticides including ethoprophos and the like in Xinhui tangerine peels and products of the Xinhui tangerine peels. The pesticides comprise the ethoprophos, sulfotep, terbufos, monocrotophos, methy-parathion, fenitrothion, isofenphos-methyl and isocarbophos. The method comprises the following steps: manufacturing a standard curve, extracting a sample, purifying the sample and determining the sample. The determination method has the advantages of simplicity and rapidness in operation, high sensitivity and strong matrix interference resistance capability, and is suitable for qualitative and quantitative analysis of pesticide residues in the Xinhui tangerine peels and the products of the Xinhui tangerine peels.

The invention discloses a methyl mercury visual detection method of gold-mercury alloy nanoparticle growth regulation and control based on a DNA template, and belongs to the technical field of heavy metal detection. According to the method, an HT9 DNA nucleic acid template is uniformly mixed with different concentrations of methyl mercury standard solutions, incubation is carried out for 5 minutesafter mixing, a sodium borohydride solution is added to prepare nano seed crystal by reduction, a hydroxylamine hydrochloride solution and a chloroauric acid solution are sequentially added then, a solution color is recorded after fully and uniformly mixing, a standard color card is established, the absorbance of the solution is determined by a microplate reader and corresponds to the concentration of methyl mercury, and a standard work curve is established. Operation is carried out by replacing the methyl mercury standard solution with a marine product extracting solution, a corresponding solution color is recorded and compared with the standard color card, the absorbance of the solution is detected and substituted into the standard curve, so that organic mercury in a marine product is detected. The method is simple, sensitive, stable and high in anti-interference capability, does not need heating, can be used to complete detection within 30 minutes, and is low in detection cost.

The invention relates to a heterogeneous photocatalysis resonance fluorescence method for accurately detecting trace uranium in an environmental water sample. The method mainly comprises the following steps: quantitatively separating the trace uranyl in a complex environmental water sample by using solid phase extraction particles UMIP having a specific recognition and adsorptive action on UO2<2+>, and adsorbing the trace uranyl to the surface of the UMIP to form a uranium-containing molecularly imprinted polymer; then accurately detecting the content of the uranium by the heterogeneous photocatalysis resonance fluorescence method. The method has the characteristics of high sensitivity, high specificity, high matrix interference resistance, simplicity, quickness and low cost. The invention also discloses a heterogeneous photocatalysis kinetic analysis and detection device which comprises a photocatalytic reaction system, a low-heat high light source, an air-cooled constant temperature system and an electromagnetic-stirring system.

The invention belongs to the technical field of physical and chemical inspection of food additive residues in tobacco essences, and particularly relates to a method for detecting five sweetening agents in a tobacco essence through the ultra-high performance liquid chromatography-tandem mass spectrometry. The method is characterized by comprising the following steps that the tobacco essence is weighed, then ultrapure water is added, then oscillating extraction is carried out, extract liquid is purified and filtered and is diluted by using the ultra-pure water, and then the sweetening agents inthe tobacco essence are directly detected through the ultra-high performance liquid chromatography-tandem mass spectrometry. The method has the advantages of being capable of rapidly and accurately detecting the residual quantity of the sweetening agents in the tobacco essence, environmentally friendly, accurate in result, less in interference, high in sensitivity and good in repeatability.

The invention discloses application of black phosphorus to detection of a matrix-assisted laser desorption ionization time-of-flight mass spectrum (MALDI-TOF MS). The molecular weight of a substance to be detected in the application ranges from 0 Da to 1000 Da; black phosphorus serves as the matrix, and has a superior mass spectrum response to small molecules containing quaternary ammonium groups; black phosphorus is soft in texture, can be directly smeared to an MALDI target plate to be analyzed, and does not need to be dispersed in a solvent in advance, and the time-consuming solvent dispersing process is omitted; moreover, it is unnecessary to consider the problem of compatibility between the matrix and the sample solvent; under irradiation of laser, black phosphorus can generate multiple phosphorus clusters used for assisting analyte in the desorption and ionization process. Compared with a traditional organic matrix, interference of black phosphorus to the small-molecule area is small; in combination with a stable isotope labeling (SIL) strategy, black phosphorus is successfully used for fast qualitative and quantitative analysis of aldehydes materials, sulfhydryl compounds and acid plant hormone in saliva, urine samples and serum.

The invention provides a determination method of pesticides including ethoprophos and the like in Xinhui tangerine peels and products of the Xinhui tangerine peels. The pesticides comprise the ethoprophos, sulfotep, terbufos, monocrotophos, methy-parathion, fenitrothion, isofenphos-methyl and isocarbophos. The method comprises the following steps: manufacturing a standard curve, extracting a sample, purifying the sample and determining the sample. The determination method has the advantages of simplicity and rapidness in operation, high sensitivity and strong matrix interference resistance capability, and is suitable for qualitative and quantitative analysis of pesticide residues in the Xinhui tangerine peels and the products of the Xinhui tangerine peels.