257 results about "Resolution (mass spectrometry)" patented technology

The invention provides a method for analyzing tobacco flavor components by adopting a multi-dimensional hyphenated chromatographic technique. The method comprises the following steps: 1. extracting the tobacco flavor components; and 2. carrying out liquid chromatography-capillary gas chromatography/mass spectrometry (LC-CGC/MS) online segregation analysis on the tobacco flavor components: A. carrying out normal phase LC segregation on the tobacco flavor components; B. storing the LC effluent components in sample loops of multiposition valves of interfaces respectively; and C. after collection of the LC effluent components is completed, ensuring the fractions stored in the sample loops of the multiposition valves to be driven by carrier gases to respectively enter into a GC/MS to undergo segregation analysis by controlling ten-way valves in the interfaces of the hyphenated instruments. The method has the following prominent advantages: the tobacco flavor components can be segregated in advance through LC, the segregated components are respectively stored in the sample loops by online coupling interfaces and then the components respectively enter into the GC/MS to undergo accurate qualitative and quantitative analysis according to difference of the boiling points. The method not only has better orthogonal segregation property, but also has higher chromatographic peak capacity and better resolution and has simple operation steps.

The invention discloses a method for screening 207 veterinary drugs and additives in animal food. The method specifically comprises the following steps: preparing a standard working solution; pretreating a to-be-detected sample; establishing a database; detecting a compound; screening the compound; confirming the compound and the like. According to the method, an ultra-high performance liquid chromatography-quadrupole rod/electrostatic field orbitrap high-resolution mass spectrometry technology is utilized to establish a rapid screening and confirmation method for simultaneously detecting 18 types of 207 compounds in animal food within 22 minutes. The method is efficient, the operability is high, good selectivity, precision and sensitivity are realized; convenient and rapid screening can be realized; the false positive rate is low; and the method is especially suitable for screening and confirmation of different kinds of compounds. The invention provides a complete rapid screening andconfirmation detection method for adding various veterinary drugs and additives into animal food, a detection and screening technical means for multiple residues in animal food is added; and the safety guarantee is provided for the national animal husbandry industry and food safety.

Prior work on differential mobility analysis (DMA) combined with mass spectrometry (MS) has shown how to couple the output of a planar DMA with the atmospheric pressure inlet of an atmospheric pressure ionization mass spectrometer (APCI-MS). However, because the ion inlet to APCI-MS instruments is a round orifice, while conventional DMA geometries make use of elongated slits, the coupling of both has attained less resolving power or tolerated a smaller sample flow rate than a DMA alone. The present invention overcomes these limitations with an axial DMA of cylindrical symmetry using more than two electrodes. The configuration is related to that previously proposed by Labowsky and Fernández de la. Mora (2004, 2006), where ions with a critical electrical mobility are brought into the symmetry axis of the DMA. Ions with this critical mobility are now optimally transmitted into the MS, with much higher resolution than possible in planar DMAs. In a preferred embodiment of this DMA facilitating DMA-MS coupling, one DMA electrode intersecting the symmetry axis is relatively planar.

The invention discloses a method for qualitatively and quantitatively analyzing a key volatile component in cigarette bead blasting. The method comprises the following steps: (1) performing full-scanning analysis on a bead blasting isopropanol solution by a gas chromatography high-resolution time of flight mass spectrometry (GC-TOF/MS) to obtain a full-scanning atlas; (2) determining an unknown material and screening the key component by an area normalization method semiquantitative result; (3) determining the mass spectrometric qualitative and quantitative parameters of the key component by taking n-propyl benzoate as an internal standard substance and by combining gas chromatogram secondary mass spectrometry (GC-MS/MS); and (4) drawing a regression curve by a gas chromatogram secondary mass spectrometry combined multi-monitoring scanning mode, and analyzing the content of the key component accurately and quantitatively. The method is simple in operation, high in sensitivity, high inaccuracy degree, short in analysis time and suitable for performing qualitative and quantitative analysis on various volatile and semi-volatile organic compounds in bead blasting simultaneously.

The invention discloses a method for identifying key toxic substances in pesticide wastewater by taking daphnia magna toxicity as a precursor and belongs to the field of identification of non-target pollutants. The method comprises the following steps: performing enrichment on organic water sample extract; performing a daphnia magna toxicity experiment on an organic water sample extract; performing fractional separation on the organic water sample extract, and separating compounds of different polarities; performing the daphnia magna toxicity experiment on the separated components; and performing qualitative identification and quantitative determination on the compounds in toxic substances. The compounds of different polarities are separated by utilizing a fractional separation technology, the toxic substances are screened to reduce the complexity of a sample, the potential toxic substances are qualitatively identified through a high performance liquid chromatography-time-of-flight mass spectrometry, suspicious toxic substances are quantitatively determined by utilizing a liquid chromatography mass spectrometry, and the defect that key toxic pollutants in a mixing system cannot be obtained by the traditional non-target chemical analysis is overcome. Meanwhile, due to fractional separation and feature object screening, the method is high in resolution ratio, high in accuracy and high in information amount, so that the identification of non-target key toxic substances is relatively convenient and reliable.

The invention discloses a spectroscopy-mass spectrometry combined quantitative analysis device for elements in an unknown sample. The device uses a quantitative analysis structure and a method by using a laser-induced breakdown spectroscopy combining with a second level extraction field time-of-flight mass spectrometry (TOF). The quantitative analysis device with high detection sensitivity, real time, quickness, high accuracy, no contact, capability of simultaneously detecting multiple elements, and no need of pretreating the sample is realized. Due to dual-wavelength laser in the device, photofragments and molecular clusters are re-ionized conveniently, the mass spectrometry signal stability is improved, and a laser plasma emission spectroscopy signal is improved; due to a second level extraction field in the device, the TOF resolution ratio is improved conveniently and the signal is optimized conveniently; due to a spectroscopy collection system in the device, the capability of collecting plasma emission light to couple to optical fiber can be improved, an optical path can be folded, the integration and the miniaturization of an instrument are facilitated, and the commercialization of the instrument is realized conveniently.

The invention discloses a method for simultaneously detecting seven fungal toxins in original auxiliary materials of baijiu. According to the method, an improved QuEChERS method is adopted for extraction, further purification is not needed, high performance liquid chromatography is utilized for achieving separation of the fungal toxins, combined quadrupole-electrostatic field orbitrap mass spectrometry (Q-Orbitrab) is achieved, efficient parent ion selectivity and high-resolution accurate molecular weight (The mass number can be accurate to five digits after the decimal point.) are combined, accurate qualitativeness and quantification of the fungal toxins in baijiu and the original auxiliary materials can be achieved, and quantification is conducted through a matrix external standard method. The fungal toxins can be completely and effectively separated within 9 min, the linear relation of the fungal toxins within separate linear response ranges is good, the correlation coefficient R<2> is larger than 0.999, the lowest limit of quantification is lower than 1.0 microgram/L, the lowest detection limit is lower than 0.1 microgram/L, the recovery rate ranges from 70% to 120%, and the relative standard deviation (RSD) ranges from 0.5% to 4%. Compared with the national standard method, the method has the advantages of being rapid, simple, convenient, economical, efficient, safe and the like and can be suitable for separation and quantitative determination of various fungal toxins in baijiu and original auxiliary material samples.

The invention discloses a method for screening a sweetening agent in milk and dairy products by applying ultra-high performance liquid chromatography-quadrupole electrostatic field orbit ion trap mass spectrometry, and belongs to the technical field of food safety inspection. An optimized QuEChERS method is used for preprocessing samples; the ultra-high performance liquid chromatography-quadrupole electrostatic field orbit ion trap mass spectrometry is applied for performing screening, a scanning mode of full-scanning/data-dependency collection and full-scanning/variable data-independent collection and full-scanning/full-ion fragmentation collection is adopted, a positive ion or negative ion mode is selected for scanning, and complete first-order and second-order spectra are obtained; Extract Finder 2.5 software is applied for processing the obtained first-order and second-order spectra, and information of a compound is extracted. Information in a built spectrum library and a tested object screening result are compared, and the composition of the sweetening agent in the milk and dairy products is ensured. An adopted mass spectrometer has the main advantages that the resolution is high, qualitative and quantitative results are accurate, sensitivity is high, and quality precision is high and can be applied to complex matrix analysis. The established screening method has the good application prospect in the field of food.

The invention discloses a method for determining organic volatile substances in soil by using the gas chromatography-mass spectrometry-headspace. The method for determining the organic volatile substances in the soil by using the gas chromatography-mass spectrometry-headspace comprises the following steps of: step 1, soil collection; step 2, sample preservation and preparation; step 3, headspace analysis; step 4, gas chromatography-mass spectrometry analysis; step 5, standard curve establishment; and step 6, calculation. The method for determining the organic volatile substances in the soil byusing the gas chromatography-mass spectrometry-headspace is characterized in that: the soil is collected into a sample bottle, and the sample bottle is sealed; meanwhile, a soil parallel sample is collected and placed in a sample bottle for sealed storage; then the sample bottles are brought back to a laboratory for analysis; the sample bottles are taken out in the laboratory and returned to theroom temperature; 2g of the sample is weighed and placed into a 22mL headspace bottle; 10mL of matrix correction solution is quickly added to the headspace bottle, and then sealed immediately; chromatographically pure methanol is taken into a sample introduction bottle; and then a volatile standard stock solution is taken into methanol. According to the invention, the organic volatile substances in the sample are not easy to volatilize and lose; the operation is convenient; the resolution is high; the linear range is good; the sensitivity is high; and the interference by the impurity peak is small.

The invention provides a device and a method of rapi`q dly and accurately detecting impurities in high-purity hydrogen for a hydrogen fuel cell. A direct sampling mode is adopted, complex sample pretreatment is omitted, and the cost and the system complexity are greatly reduced; high-purity hydrogen is taken as a carrier gas for quantitative sampling, and a standard gas is taken as reference, so that accurate quantification is realized; the special mass spectrum device for hydrogen detection greatly improves low-end mass number resolution, detection stability and sensitivity, and the system stability is remarkably superior to that of a general chromatographic mass spectrometry method; a special control software system comprises a mass axis automatic calibration software module, a high-purity carrier gas automatic measurement software module, a standard gas quantitative automatic measurement software module, a sample quantitative automatic measurement software module, a sample impuritygas automatic calculation software module, and due to a built-in algorithm, measurement and control automation are realized. The characteristics are beneficial to rapid and accurate determination of the high-purity hydrogen impurities of the hydrogen station of the hydrogen fuel cell.

The invention relates to a method for screening a feature marker for identifying a honey producing place. According to the method, a simple sample pre-treatment process is performed; then, a great amount of high-resolution mass spectrum data is obtained by an ultra-high performance liquid chromatography-quadrupole/electrostatic field orbital hydrazine high-resolution mass spectrometry; deviation and variation interference in experiment data are eliminated through background removal, chromatographic peak extraction, normalization, data conversion and data zooming; then, through main ingredient analysis, t-inspection, Volcano plots and variable importance projection drawing, the real feature markers capable of distinguishing the same honey source honey from different producing places can be discovered and verified. After the feature marker is used for identifying the honey producing place, identification results are objective and precise; the method can be used for the variety source tracing identification of honey of the same honey source from different producing places, and can also be used for the variety source tracing and producing place tracing identification of other farm products.

An analysis method for dynamically tracing and monitoring nicotine and nicotine metabolites in an animal is characterized in that the animal is exposed after pyridine ring 2H labeled nicotine ([2H4]-(+/-)-Nicotine) and unlabeled nicotine are mixed in equal proportion, a micro-dialysis system is utilized to respectively collect blood and brain dialysate samples in a micro-centrifuge tube, the samples are directly put on an ultra high performance liquid chromatography-orbit trap to conduct high-resolution mass spectrometry detection on the nicotine metabolites and pyridine ring 2H labelers of the nicotine metabolites in the micro-dialysis samples after an analyzing interior label is added for short-term low-speed centrifugation, the nicotine metabolites are identified according to test results, and a corresponding time-concentration curve is drawn for dynamic monitoring and analysis. The analysis method has the advantages that a variety of nicotine metabolites in animals can be accurately traced and identified, a sample pretreatment step is greatly simplified, accurate analysis and synchronous comparison of nicotine metabolite changes in different systems in animals are achieved, and a novel method for researching the nicotine metabolites in animals is created.

The invention relates to a method for rapidly analyzing lipid components in bee pollen. The method comprises the following steps: using an ultra performance liquid chromatography and quadrupole-static electric field orbitrap high resolution mass spectrum coupling technique (UPLC-Q-Exactive Orbitrap MS), and using positive and negative ion monitoring mode, full-scanning and the function of automatically triggering a tandem mass spectrometry scanning to accurately realize precise quantification of lipid components in bee pollen from different plants, and providing the basis for the origin place of bee pollen, authenticity judgment, doping counterfeiting and functional nutriology research of bee pollen. The technology is high in resolution ratio and accurate in positioning, overcomes the problems of low accuracy and reliability in ingredient identification in the prior art, and is a novel efficient technology for lipid component analysis.

The invention discloses a Xinjiang artemisia plant metabonomics analysis method. The method comprises the following steps: 1) taking dry powder of different tissue organs of Xinjiang artemisia, respectively performing steps of extraction with an organic solvent, ultrasonic wave, centrifugation, and condensation to obtain a concentrate, then performing redissolving, ultrasonic wave, centrifugationand filtering on the concentrate, and taking supernatants of metabolome of the different tissue organs; 2) employing a liquid chromatogram-tandem mass spectrometry on the supernatants of metabolome ofthe different tissue organs, and processing the obtained data; employing multivariable statistics analysis to obtain differential variables, according to a high-resolution mass-to-charge ratio and tandem mass spectrum data of the differential metabolite, and combining a metabolite database Metlin retrieval contrast analysis, obtaining the difference of the plant metabolome of the different tissueorgans of the Xinjiang artemisia. The method has the advantages that pre-treatment operation on a sample is simple, the stability of an analysis method is good, sensitivity is high, a metabolite covering range is wide, and the metabolome information of the plant can be efficiently and comprehensively obtained.

The invention relates to a high performance liquid chromatography-time-of-flight mass spectrometry method for identifying a degradation product in a compound cold treatment medicine based on a heart-cutting technology. The method comprises the following steps: separating a sample by using a mass spectrum incompatible mobile phase in a first-dimensional chromatograph; acquiring ultraviolet data through a one-dimensional detector; determining a target peak, and carrying out heart-cutting to make the target peak exist in a sample loop; carrying out back flushing through valve switching by using a two-dimensional system using a mass spectrum compatible mobile phase to make the target peak exist in the two-dimensional system and enter a two-dimensional ultraviolet and mass spectrum detector in order to complete impurity analysis and identification. The method has the advantages of no change of original separation conditions, high specificity, accuracy and resolution in impurity detection, and improvement of the reliability of nonvolatile buffer salt separation system impurity mass spectrometry and identification.

The invention relates to a method for simultaneous chiral resolution and determination of nicotine and nornicotine in electronic cigarette liquid. The method comprises the following steps: 1) mixing the electronic cigarette liquid with isopropanol and successively carrying out ultrasonic extraction and filtering so as to obtain a to-be-detected solution; and 2) analyzing the to-be-detected solution obtained in the step 1) by using ultra-performance convergence chromatography-tandem mass spectrometry. The method for simultaneous chiral resolution and determination of nicotine and nornicotine in the electronic cigarette liquid is simple in pre-treatment, rapid in determination and high in sensitivity and is a good method for determination of chiral substances in nicotiana alkaloids; and the method does not use any chiral shift reagent, can realizes simultaneous resolution of chiral isomers of the two alkaloids, i.e., nicotine and nornicotine, in the electronic cigarette liquid, and is high in analysis efficiency and friendly to environment.

The invention discloses a new Gelsmium elegans Benth. alkaloid compound as well as a preparation method and application thereof. In the preparation method, a target compound is separated from Gelsmium elegans Benth. by using a pH-zone-refining countercurrent chromatography and taking a total Gelsmium elegans Benth. alkaloid crude extract as a raw material and a high-speed counter-current chromatographic instrument as separation equipment; and the method has the advantages of large preparation amount, less sample loss and strong controllability, and is convenient and fast and is suitable for industrial production. By the determination of high-resolution mass spectrometry, ultraviolet spectrum, infrared spectrum, <1>H, <13>C-NMR (nuclear magnetic resonance) spectrum, <1>H-<1>HCOSY (correlation spectrometry), HSQC (heteronuclear single quantum coherence) spectrum and HMBC (heteronuclear multiple-bond correlation) spectrum, the new Gelsmium elegans Benth. alkaloid compound has the structure of a formula (I). A pharmacological test shows that the compound in the invention has dose dependence, powerful analgesic effect, less tolerance, addiction and side effect and treatment index far higher than that of total Gelsmium elegans Benth. alkaloid, can be used for preparing a novel powerful low-toxicity medicament or lead compound used for treating pain, and has definite industrial prospect.

Disclosed is a method for detecting disulfide bond breakage of protein. The method for detecting disulfide bond breakage of the protein comprises utilizing iodoacetic acid to react with free sulfydryl, removing unreacted iodoacetic acid through filtration, breaking the disulfide bonds inside the protein through dithiothreitol, utilizing ammonium iodoacetate to react with newly-produced sulfydryl, utilizing trypsin to hydrolyze the protein into polypeptide, detecting the mass to charge ratio information of the polypeptide through high-resolution mass spectrometry and comparing the mass to charge ratio information with the disulfide bond information of natural protein to determine whether the disulfide bonds break. The method for detecting disulfide bond breakage of the protein can be effectively used for determining whether the sulfydryl exists in a free or disulfide mode; the mass difference caused by reactions between the iodoacetic acid as well as the ammonium iodoacetate and the sulfydryl can be within 1Da, so that the difference between the two reactions can be determined very accurately through the high-resolution mass spectrometry; accurate judgment on whether the disulfide bonds of the protein break can lay the foundation for relevant theoretical researches and provide theoretical foundation for modification of specific proteins and actual production.

The invention provides a method for simultaneously detecting various trace persistent halogenated organic pollutants in insects. A target compound is extracted by adopting an accelerating solvent, concentrated sulfuric acid and concentrated hydrochloric acid are used for purification at the same time, different target compounds are separated by utilizing different types of solid-phase extraction small columns, and the synchronous extraction and purification process of various POPs is realized; and adding corresponding 13C isotope internal standard and deuterated recovery rate indicators to perform quality control on the pretreatment process and instrument detection errors and perform quantitative analysis on the target compound. The organic pollutants are detected by a sampling isotope dilution method and a high-resolution gas phase/liquid phase mass spectrometry method, and a high-sensitivity quantitative detection result is obtained. According to the method disclosed by the invention, the measurement accuracy and reliability of trace persistent organic pollutants contained in insects are ensured, and a new technical means is provided for quick screening and accurate quantification of multi-component persistent organic pollutants in a complex matrix.

The invention discloses a new method for quantitative analysis on chromatographic peaks under a complex environment in liquid chromatography-mass spectrometry data and belongs to the field of analyticchemistry. The method includes the steps of: a) quickly reading an XML file of original mass spectrometry data to obtain extract ion chromatogram map of each to-be-quantified substance, and finding potential chromatographic peaks in the extract ion chromatogram map by means of chromatographic peak span value, which is an index having definite physical meaning; b) on the basis of a result in the step a), comparing adjacent potential chromatographic peaks according to chromatographic attribute features such as peak height, peak distance, peak area and the like, and further performing effectivefusion; and c) according to the characters of the chromatography-mass spectrometry data, comprehensively analyzing possible chromatographic peak shapes and noise influence in the liquid chromatography-mass spectrometry analysis process to dynamically regulate the chromatographic peaks. By means of the new method for accurate quantification on the basis of complex liquid chromatography-mass spectrometry data, number, position, height and area of the chromatographic peaks within the same retention time range can be obtained. The method is suitable for quick, accurate, batched and quantitative analysis for high-resolution liquid chromatography-mass spectrometry data under low signal to noise ratio and under a complex background.