212 results about "Stable isotope ratio" patented technology

The invention provides a new method for double quantifying the protein group marked on the basis of stable oxygen isotope <18>O, which is characterized in that: based on the fact that the N end peptide section and the C end peptide section are generally labeled, and by means of combining the <18>O chemical labeling and enzyme digestion, the quantifying strategy for two <18>O markings of the same sample can be accomplished. The method relates to the reductive alkylation and enzyme digestion of protein, dual-functional reagent modifying and <18>O marking of peptides, multi-dimensional liquid phase chromatogram separation and multistage Tandem Mass Spectrometry quantification and identification. A first mass spectrum peak area is used to quantify; and the identification of the protein is conducted through a second stage mass spectrum and by searching the database. The invention also provides a reagent box for facilitating the implementation of the method.

The invention relates to an online analysis method for sulfur isotope of hydrogen sulfide gas in natural gas. The method comprises the steps of collecting a natural gas sample; heating oxidation furnace of an elemental analyzer to 1,020 DEG C; heating a chromatographic column box to 50 DEG C; introducing reference gas into a stable isotope ratio mass spectrometer, adjusting center magnetic field of the peak with mass / charge ratio of 66, and storing the magnetic field value; connecting a steel cylinder filled with the natural gas sample with a sampling valve, placing in a ventilating hood, and switching on the ventilating hood; taking the natural gas sample with an airtight sample injector; injecting the natural gas sample into a sample inlet; introducing the natural gas sample into a high-temperature oxidation tube with carrier gas, to be oxidized into carbon dioxide, water and sulfur dioxide gas, carrying the mixed gas with carrier gas through a dewatering tube for water removal; separating the dewatered mixed gas with a gas chromatographic column, sequentially introducing into a stable isotope ratio mass spectrometer through a continuous flow interface, measuring sulfur isotope composition, and generating spectrogram.

The invention relates to a GC-IRMS direct measurement method for hydrogen sulfide sulfur isotope in mixed gas, which comprises the steps of: firstly, by utilizing a gas chromatogram-stable isotope ratio mass spectrum combined instrument with I s o d a t N T 2.0 software, carrying out the magnetic field control so that an intermediate receiving cup receives ions with the receiving charge-to-mass ratio of 35, which are 35H2S, and correspondingly, receiving cups on two sides respectively receive ions with charge-to-mass ratios of 34 and 36, which are 34H2S and 36H2S, and recording a numerical value of a magnetic filed at the moment; then correcting the instrument by H2S reference gas; secondly, injecting a plurality of gas samples containing 1-5ml H2S into a gas chromatograph in the instrument, and meanwhile obtaining gas chromatograms of 36H2S, 35H2S and 34H2S and gas chromatograms of ratios of 36H2S / 34H2S and 35H2S / 34H2S; finally, processing obtained data to gain a value of hydrogen sulfide sulfur isotope in a mixed gas sample. The GC-IRMS direct measurement method has the characteristics of simpleness, rapidness, accuracy and small sample consumption, and does not need sample preparation and correction of interference isotopes.

The invention relates to a low-temperature finestiller for separating stable isotope elements, wherein it comprises at least one low-temperature finestill tower, which is packed with multilayer thermal-insulated layer at high vacuum; the tower is filled with multilayer stuff; the density of multilayer thermal-insulated material is 10-150layer / cm; the vacuum of thermal-insulated layer is lower than 10-1Pa; the stuff is wave stuff as plate wave stuff and mesh wave stuff as best. The inventive separating method comprises processing low-temperature gas-liquid conversation in the low-temperature finestill tower, to separate the isotope elements. The invention can be used in CO, CH4, NO, BF3, O2, H2, He, or Ne to separate 3CO, 3CH4, C18O, 18OO, 15NO, N18O, 10BF3, 2H, 3H, 3He, 22Ne, 12CO, 12CH4, N16O, 14NO, 11BF3, and 20Ne.

The invention relates to a method for identifying original wines based on stable isotope ratio, and belongs to the technical field of trueness identification of wines. The method mainly comprises the following steps of: (1) measuring the delta 180 of alcohol contained in a true original wine sample by adopting a gas phase chromatography / stable isotope mass spectrometry coupling technology, and establishing a delta 180 database of the true original wine sample; (2) measuring the delta 180 of the alcohol contained in a wine sample to be measured; (3) analyzing the significant difference of the delta 180 of an alcohol content contained in the wine sample to be measured and the delta 180 of the alcohol contained in the true original wines, wherein if no significant difference exists, the wine sample to be measured and the true sample are indicated to be from a same producing area, and if the significant difference exists, the wine sample to be measured and the true sample are indicated to be from different producing area. The method capable of accurately identifying the original wines, which is disclosed by the invention, is established by utilizing a stable isotope mass spectrometry technology, can be used for solving the technical problem of national original wines on market supervision and is conductive to specifying the market behaviors, protecting the benefits of consumers and legal enterprises and promoting the healthy and orderly development of a wine industry.

The invention discloses a method for judging the place of production of traditional Chinese medicinal pulsatilla by using a stable isotope ratio. According to the method, the values of N%, C%, sigma 15N and sigma 13C in a pulsatilla sample are measured by an elemental analysis-stable isotope mass spectrometry technology. The method mainly comprises the following steps of constructing a database including N%, C%, sigma 15N and sigma 13C of the pulsatilla sample in the real place of production by measuring the values of N%, C%, sigma 15N and sigma 13C in the pulsatilla samples in different places of production; measuring the values of N%, C%, sigma 15N and sigma 13C in an unknown place of production; performing Fisher judgment analysis by statistical software, and running a program to judge the real place of production of the pulsatilla sample in the unknown place of production. According to the method disclosed by the invention, the method for accurately judging the place of production of the pulsatilla can be constructed by the elemental analysis-stable isotope mass spectrometry technology, so that the technical difficulty in tracing of the place of production of traditional Chinese medicines in China can be solved; the benefit of a customer can be protected, and the traditional Chinese medicine industry can be developed in a healthy and ordered way.

The invention discloses a Myrica rubra original place tracing method based on stable isotope ratio and multi-element. The method comprises: collecting and pre-processing Myrica rubra samples from different places; subjecting the samples to analysis of the stable carbon, the nitrogen isotope ratio, the stable oxygen, the hydrogen isotope ratio and the multi-element; for the data of the Myrica rubra samples from known areas, using the mode featuring the combination of the PCA method and the LDA method to analyze the data obtained from the Myrica rubra samples from known areas; establishing an original place tracing model to judge the original place of the samples; and using the data obtained from the Myrica rubra samples from unknown areas to be inputted into the original place tracing model to make the analysis and judgment so as to obtain the original place tracing for the Myrica rubra samples from unknown areas. For the first time, the invention adopts the technology featuring the combination of the principal component analysis with the linear judgment to establish a Myrica rubra original place tracing method.

This invention refer to microbe restoring of polycyclic aromatic hydrocarbon ( PAHs) contaminated soil technology region. This invention utilizes phospholipid fatty acid analyzing ( PLFA) technology and stable isotope ratio mass-spectrometric technique ( IRMs) to judge normal position high performance degradation germ in PAHs contaminated soil. The invention takes phospholipid fatty acid as biological tag, combine with stable isotopic tracer technology, base on delta value difference of phospholipid fatty acid abstracted from soil to judge degradation bacterium or florae of PAHs in normal position soil, also can judge given strain whether is autochthon degradation bacterium of contaminated soil. This method can validly combine microbial community architecture with function. This invention aim at supplying a method of verity reflecting degradation bacterium or florae in PAHs contaminated soil, thereby could analyze selected strain whether or not is autochthon degradation bacterium and its degradation ability.

The invention relates to an online monitoring system of a greenhouse gas and a stable isotope of the greenhouse gas. The online monitoring system comprises a measurement module and a data acquisition and control module. The online monitoring system is characterized by further comprising an automatic sample feeding module and a power device, wherein an outlet of the automatic sample feeding module is connected with an inlet of the measurement module, the power device is connected with an outlet of the measurement module to provide power to the sampling, and the output end of the data acquisition and control module is connected with the automatic sample feeding module, the measurement module and the power device and the data acquisition and control module controls all the modules to cooperatively and synchronously work. The online monitoring system has the beneficial effects that the automatic sample feeding module and the power device continuously suck air to an optical attenuation cavity for performing automatic and continuous measurement, a tunable laser generates light with a plurality of specific wavelengths, multiple components can be measured; the wavelength resolution can reach 0.0001 cm<-1>, the anti-interference capacity is strong; and by adopting an optical cavity attenuation detection technology, a gas concentration is in direct proportion to an attenuation time, the influence by light source fluctuation and a light intensity attenuation factor is small, the stability is good, and the measurement value is accurate.

The invention relates to a method and a device for concentrating and enriching stable isotopes 2H, 18O and 13C. The method comprises the steps of: by taking compounds respectively containing stable isotopes 2H, 18O and 13C as materials, carrying out purification treatment, adding to a heavy isotope concentration tower group formed by a plurality stages of gas-liquid mass transfer towers connected in series; continuously and partially vaporizing and partially condensing in the gas-liquid mass transfer towers connected in series by weak vapor pressure difference between light and heavy isotopes of hydrogen, oxygen, and carbon elements, and gradually concentrating and purifying corresponding heavy isotope. Each tower disclosed by the invention adopts different operation pressures and coupling utilization of heat between the towers; over 30-40% of energy consumption can be saved; a composite structure mass transfer component composed of a liquid collecting distributer, a Dixon mass transfer component, a corrugated mass transfer component and the like is adopted inside the tower; the device is easy to amplify; the device of producing heavy 2H, 18O or 13C isotope at a large scale just needs to be connected with 2-8 gas-liquid mass transfer towers in series; over 50% of investment is saved in comparison with the same scale of device, and the towers adopt a single tandem cascade technology; and the method is simple in flow and easy to control and operate.

The invention discloses a method for distinguishing production places of cordyceps sinensises based on stable isotope ratio, and belongs to the field of a cordyceps sinensis authenticity distinguishing technology. The method comprises the following main steps: (1), detecting the delta 15N value of a cordyceps sinensis sample of a real production place with a stable isotope mass-spectrometric technique, constructing a delta 15N database of the cordyceps sinensis sample of the real production place; (2), detecting the delta 15N value of a to-be-detected cordyceps sinensis sample; (3) performing significant difference analysis on the delta 15N value of the to-be-detected sample and the delta 15N value of the cordyceps sinensis sample of the real production place in the database, indicating that the to-be-detected sample and the real sample are from the same production place if the significant difference is inexistent, and otherwise, indicating that the to-be-detected sample and the real sample are from different production places. A method capable of exactly distinguishing production places of cordyceps sinensises is provided by using the stable isotope mass-spectrometric technique, consequently, the technical problems in market supervision of the production places of cordyceps sinensises in China is solved, the method is beneficial for standardizing market behavior, protecting legal interests of consumers and enterprises, and improving the cordyceps sinensis industries to develop in a healthy and ordered way.

The invention relates to a method for identifying a panax notoginseng root tuber production place based on stable isotope fingerprints, and belongs to the field of production place tracing of authentic Chinese medicinal materials. The method comprises steps as follows: (1), three-year spring panax notoginseng root tuber samples of any one place of Baise of Guangxi province, Wenshan of Yunnan province and a newly expanded area of Yunnan province are collected; (2), the collected three-year spring panax notoginseng root tuber samples are washed, dried and smashed; (3), rates of panax notoginseng powder stable isotopes delta <2>H, delta<18>O, delta <13>C and delta <15>N are detected, and the unit is permillage; numerical values of Y(Baise district of Guangxi province), Y(Wenshan district of Yunnan province) and Y(newly expanded district of Yunnan province) can be obtained according to discrimination models (1), (2) and (3), and a panax notoginseng sample comes from the region with the maximum numerical value. A producing place discrimination model is built according to stable isotope fingerprint characteristics of four elements of C, H, O and N from start of stable isotope fingerprint difference of panax notoginseng, a few test indexes are used, the accuracy is high, uncertainty based on labels and subjective judgment is reduced, and the overall discrimination rate of sources of three-year spring panax notoginseng production places can be higher than 84%.

The invention provides a method for distinguishing production places of flat tea based on stable isotope proportion difference. The method is characterized by mainly comprising the following steps: (1) collecting samples and establishing a modeling sample set; (2) detecting stable isotopes, wherein determined indexes are 13C / 12C, 15N / 14N, 18O / 16O, D / 1H, 111Cd / 113Cd, 206Pb / 207Pb, 207Pb / 208Pb and 88Sr / 86Sr; (3) carrying out data standard processing and sample assignment to obtain variables Z(C), Z(N), Z(O), Z(D), Z(Cd), Z(206Pb / 207Pb), Z(207Pb / 208Pb) and Z(Sr); (4) establishing a decision-making tree analyzing model; (5) judging unknown samples. With the adoption of the method provided by the invention, the quality safety of tea leaves can be met, and the faking of the tea leaves can be effectively prevented; the production places are distinguished through decision-making tree analysis, the accurate distinguishing rate of a return test reaches 91.35 percent, the accuracy of an external test reaches 92 percent, and the model is reliable.

The invention relates to a Wuyi rock tea production place identification method based on deep learning, and belongs to the technical field of authenticity identification of geographical indication products. The method aims at solving the problems that a single kind of detection data can not represent complete key information about production place tracing, and different kinds of detection data are not matched when used in combination in a metrological method. According to the method, based on a neural network ELM model with a deep learning function, an ELM analysis model is established for stable isotope data, microelement data, electronic tongue data and fused data of the three kinds of data of rock tea from different production places with the same method; after sample extraction, the production places of the rock tea are subjectively and accurately judged with the model. The model established with the fused data of the three kinds of data has the highest identification rate which reaches 100.0% and is far higher than that of the discrimination result of a neural network model established with a single kind of data; besides, the identification rate on blind samples reaches 100%. The method has good application prospects and can serve as a technical method for tracing identification of Wuyi rock tea production places.

The invention relates to a yak meat production place tracing method based on multiple elements and stable isotopes. The method comprises the steps of (1), collecting a yak meat sample and carrying outpreprocessing to obtain a defatted yak meat sample; (2), detecting a stable carbon isotope abundance ratio, a stable hydrogen isotope abundance ratio, and a mineral element Ti content in the defattedyak meat sample; (3), carrying out computing to obtain a stable carbon isotope ratio delta<13>C%o and a stable hydrogen isotope ratio delta<2>H%o according to the stable carbon isotope abundance ratio and the stable hydrogen isotope abundance ratio; and (4), substituting the stable carbon isotope ratio delta<13>C%o, the stable hydrogen isotope ratio delta<2>H%o and the mineral element Ti contentinto a judgment model, and judging a production place of the yak meat sample according to a computing result. The method is simple and convenient and is high in operability. Influence of external environment factors on yak meat production place tracing accuracy is effectively reduced. The yak meat production place tracing accuracy can be improved. The method is characterized by speediness, economyand practicality.

The invention relates to a method for fast determination of oxygen isotope composition of water in beverage wine and belongs to the technical field of stable isotope analysis. The method comprises carrying out gas chromatographic column separation on water and other oxygen-containing organic matters in a beverage wine sample, transforming the water into carbon monoxide by a pyrolysis method, determining produced carbon monoxide delta<18>O by a stable isotope ratio mass spectrum, and carrying out calibration by international or national water reference substances to obtain oxygen isotope composition of water in beverage wine, wherein the composition is characterized by delta<18>O.

The invention provides a generator capable of generating water vapor with different concentrations and a constant hydrogen and oxygen stable isotope ratio according to the requirement and a method thereof. The method can be used for demarcating an atmosphere water vapor stable isotope instrument, realizing performance assessment or demarcation of an instrument in succession or at regular intervals, or directly be used for the generator generating the water vapor with different concentrations. The generator is beneficial to installation and disassembly in the wild. The generator comprises six parts: (1) a trace water-dripping device; (2) an evaporation device; (3) a constant temperature heating device; (4) a dry air injecting device; (5) a water vapor outlet; and (6) an air mixing device.

The invention discloses a method for tracing and verifying the origin of pure natural fruit products. The method comprises: 1) acquiring the stable isotope ratio of pure natural fruit products of different origins, and establishing a database for the stable isotope ratio of pure natural fruit products of different origins; 2) detecting the stable isotope ratio of to-be-tested pure natural fruit products; and 3) comparing the stable isotope ratio of the to-be-tested pure natural fruit products detected in step 2) with the stable isotope ratio in the database in step 1), thereby determining the origin of the to-be-tested pure natural fruit products. Specifically, the stable isotope ratio includes at least one of delta<13>C value, delta<15>N value, deltaD value and delta<18>O value. According to the technical scheme of determining and comparing at least one of the four stable isotope ratios, the origin of pure natural fruit products can be rapidly and easily traced and verified, especially when the four stable isotope ratios are determined and compared simultaneously, the correct discriminant rate is at least 90%.

The invention provides a method for determining nitrogen or carbon isotope ratio of N2 or CO2 gas on the basis of an elemental analyzer-stable isotope mass spectrometer combined device. The method comprises the following steps of: continuously introducing inert gas from a gas inlet of an oxidation tube of an elemental analyzer; injecting the to-be-detected gas sample N2 or CO2 through a sampling port of a gas sampling device; causing the to-be-detected gas sample N2 or CO2 together with the inert gas enter into a stable isotope mass spectrometer through a reduction tube of the elemental analyzer; and determining the nitrogen or carbon isotope ratio by the stable isotope mass spectrometer. According to the method provided by the invention, working standard gas N2 and CO2 can be determined and meanwhile the pure natural abundant N2 and CO2 gas sample also can be determined; the required external device is saved when the stable isotope mass spectrometer is used for determining the gas sample; the method provided by the invention is simple, convenient and high in result accuracy.

Gas having stable isotopes is monitored continuously by using a system that sends a modulated laser beam to the gas and collects and transmits the light not absorbed by the gas to a detector. Gas from geological storage, or from the atmosphere can be monitored continuously without collecting samples and transporting them to a lab.

The invention relates to the isotope measurement technology, in particular to an accelerator mass spectrometer with a simultaneous isotope measurement function. The accelerator mass spectrometer structurally comprises a sputter negative ion source used for generating negative ions and connected with an accelerating tube used for simultaneously accelerating a plurality of isotope ions, wherein the output end of the accelerating tube is connected with an isotope mass resolution system; the isotope mass resolution system is connected with a charge converting analysis and multi-receiving measurement system; the charge converting analysis and multi-receiving measurement system is connected with an ion detection system. The accelerator mass spectrometer can simultaneously accelerate a plurality of isotope negative ions, stable isotope negative ions in the accelerated isotope negative ions are measured by a stable isotope receiver, unstable isotope negative ions are converted into positive ions which are then measured by a detector, and measurement signals are simultaneously transmitted to a nuclear electronics and data acquisition unit after time matching for data operation. The accelerator mass spectrometer is simple in structure, convenient to operate and maintain and high in measuring accuracy.

The invention relates to a synthetic method for a stable isotope labeling basic orange II. The synthetic method comprises the steps of: carrying out nitration reaction by taking stable isotope labeling benzene as a raw material to generate stable isotope labeling nitrobenzene; then, subjecting the stable isotope labeling nitrobenzene and a reducing agent to reaction to obtain stable isotope labeling phenylamine; and finally, carrying out diazotization and m-phenylenediamine coupling transposition to obtain the stable isotope labeling basic orange II. After being separated and purified, the stable isotope labeling basic orange II prepared by the invention has the chemical purity of over 98% and the isotope abundance of over 98% and can sufficiently meet the requirement for detecting prohibited dyes in the field of food safety.

The invention discloses a potato production place tracing method based on mineral elements and stable isotopes. The method comprises the steps: respectively collecting potato samples of potato production bases of four provinces: Inner Mongolia, Heilongjiang, Xinjiang and Sichuan, and preparing analysis samples; determining the contents of aluminum, manganese, copper and zinc, the carbon stable isotope ratio delta < 13 > C and the nitrogen stable isotope ratio delta < 15 > N in the obtained analysis sample; substituting the determination result into a discrimination model, and determining the production place of the potato sample. The potato production place tracing method is based on mineral elements and stable isotope contents of different origins, the sources and accuracy of different potato products can be explained by utilizing an objective detection technical means, the accuracy rate is not less than 95.3%, the blank of lack of a potato traceability technology is filled, data support can be provided for protecting potato regional brands with production place advantages, the phenomenon of shoddy goods is avoided, and the method has a wide application prospect.

The invention relates to a method for producing a stable isotope <13>C by adopting a chemical catalysis exchange method. The method adopts a CO2 / carbamate gas-liquid countercurrent chemical catalysis exchange system to perform chemical exchange and separation in a packing tower, wherein, a gas phase is the CO2, and a liquid phase is an amic organic solvent; the packing tower is regular packing or random high-efficiency packing; and a separating system realizes the separation of the stable isotope <13>C in a multi-tower concatenation connection. Compared with the prior art, the method has the characteristics of simple process, low production cost, normal-temperature normal-pressure operation and so on.

The invention provides a method for measuring the carbon, hydrogen and nitrogen stable isotope ratios of nicotine in an electronic tobacco smoke solution. The method is characterized by comprising the following steps of: performing liquid sampling after diluting the electronic tobacco smoke solution with an organic solvent; separating nicotine from other impurities of 1,2-propanediol and propanetriol by use of a gas chromatograph provided with a capillary chromatography column; analyzing the carbon stable isotope ratio value delta13C, hydrogen stable isotope ratio deltaD and nitrogen stable isotope ratio delta15N of nicotine in the electronic tobacco smoke solution by use of gas chromatography-isotope mass spectrograph (GC-IRMS); and calibrating and calculating the delta12C, deltaD and delta15N of nicotine in the electronic tobacco smoke solution according to delta12C, deltaD and delta15N measured values of a nicotine isotopic standard substance. By use of a GC-IRMS technology, measurement of the carbon, hydrogen and nitrogen stable isotope ratios of nicotine in the electronic tobacco smoke solution is realized for the first time at home and abroad, and a technical method is provided for judging nicotine sources in the electronic tobacco smoke solution.

The invention discloses a method for pre-treating an animal sample for stable isotope detection. The method comprises the following steps: putting the animal sample into a utensil without stable isotope interference and freeze-drying the animal sample, and then grinding the animal sample into powder by using the utensil without stable isotope interference so as to finish the pretreatment for detecting the stable isotope in the animal sample. According to the method, a ceramic mortar, scissors or a cutter without stable isotope interference is selected to cut and grind the animal sample, and the freeze-drying step is used to replace a hot drying step in the existing method to reduce the exchange between the stable isotope in the hot drying air and the same stable isotope in the sample. When the detection of the stable isotope is performed after the animal sample is pre-treated by the method, the stable isotope detection result is accurate, and multiple detection results have small coefficient of variation, so the method provided by the invention is a simple, accurate and effective pre-treatment method for the stable isotope detection of the animal sample and is favorable for improving efficiency and accuracy of the stable isotope detection in agricultural products.

A method for measuring ratio of nicotine carbon, hydrogen and nitrogen stable isotopes in tobacco is characterized in that extracting nicotine from tobacco by using an n-hexane and sodium hydroxide solution system, performing liquid sample injection, separating the nicotine from other impurities in extract by using a gas chromatograph fitted with a capillary chromatographic column, analyzing carbon stable isotope ratio Delta 13C, hydrogen stable isotope ratio (Delta D) and nitrogen stable isotope ratio Delta 15N in the nicotine by using a gas chromatography and isotope ratio mass spectrograph (GC-IRMS), and calibrating and calculating the values Delta 12C, Delta D and Delta 15N of the nicotine in tobacco according to measured values Delta 12C, Delta D and Delta 15N in nicotine isotope standard matters. By using GC-IRMS technology, nicotine carbon, hydrogen and nitrogen stable isotope ratio in tobacco can be measured quickly and accurately, and a technique is provided for tracing tobacco products.

The invention relates to a stable isotope labeled benzyl butyl phthalate and a synthesis method thereof. According to the invention, an organic synthesis method is adopted; stable isotope labeled phthalic anhydride is adopted as a raw material, and is subjected to a reaction with benzyl alcohol, such that stable isotope labeled monobenzyl phthalate is produced; the stable isotope labeled monobenzyl phthalate is subjected to a reaction with butanol, such that stable isotope labeled benzyl butyl phthalate is obtained. Compared with the prior art, when the stable isotope labeled benzyl butyl phthalate is separated and purified, a chemical purity can be higher than 99%, and an isotope abundance is higher than 99%, such that the demand of the detection of the illegal additive benzyl butyl phthalate in the field of food safety can be fully satisfied.