21 results about "Stable isotope ratio" patented technology

The invention belongs to the technical field of environment monitoring, and particularly relates to a quantitative recognition method for contribution of autogenous source organic carbon of a surface water body. Based on the stable isotope ratio and the three-dimensional fluorescence spectrum, the water DOM source analysis method is constructed, the source and characteristics of DOM are comprehensively analyzed, and the characteristic information and contribution of autogenous source organic carbon are specifically recognized. The three-dimensional fluorescence spectrum has the advantages of being rapid in detection, small in sample use amount and the like, DOM sources can be rapidly and qualitatively identified, different DOM sources can be quantitatively calculated through stable isotope ratio analysis, and meanwhile the research area land utilization, hydrological water environment and water quality parameters are combined, so that the DOM sources can be rapidly and qualitatively identified. And the source and migration rule of the DOM in the water body can be determined more comprehensively. The quantitative identification method provided by the invention has the advantages of more comprehensive water DOM research, more complete identification system and more reliable traceability result.

The invention discloses a device and a detection method for online oxidation-enrichment-reduction determination of nanogram-level nitrogen isotopes in a solid, and belongs to the technical field of nitrogen isotope analysis. The device comprises an oxidation system, a nitrogen oxide enrichment system, a nitrogen reduction system, a mass spectrum interface system, a stable isotope ratio mass spectrometer and pipelines for connecting all parts of the device. The device provided by the invention greatly reduces the quantitation limit of the nitrogen isotope in the solid sample, can realize high-precision determination of the nanogram-level nitrogen isotope in the solid sample, and has the advantages of simplicity and convenience in operation, high accuracy and the like.

The invention provides a method for analyzing the oxygen stable isotope ratio of water in a highly alcoholic beverage, and relates to the technical field of oxygen isotope analysis. The analysis method comprises the following steps: selecting at least two water samples with known oxygen isotope ratios and different values as additive water; diluting the same high-alcohol beverage to be detected by adding water to obtain a diluted sample; measuring an oxygen isotope ratio; and according to the oxygen isotope ratio of the added water and the oxygen isotope ratio of the diluted sample, calculating the oxygen isotope ratio of the water in the highly alcoholic beverage to be measured. According to the analysis method, the concentration of ethanol is reduced through dilution, so that interference of isobaric elements is avoided; and physical separation is replaced by mass conservation equation calculation, and a complex distillation device is not needed. According to the method, pretreatment is remarkably simplified, cost and errors are reduced, and rapid and accurate analysis of the water oxygen isotope in the highly alcoholic beverage is achieved.

The present application relates to a method for identifying different seasons of tea, and belongs to the technical field of tea quality detection. The existing tea season identification relies on sensory or single component analysis, which is highly subjective and lacks accuracy. The present application collects tea samples, detects the δ 15 N stable isotope ratio and the contents of EGC, EGCG, ECG and CAF organic components in the tea samples, and substitutes these data into the linear discriminant models for spring, summer and autumn respectively to calculate the values of Y 春季 , Y 夏季 and Y 秋季 . The season corresponding to the largest value is the season to which the tea sample belongs. This method uses multiple indexes in combination with linear discriminant models to objectively identify the season of tea, and can be used in tea quality control, market supervision and tea traceability, etc., providing a scientific basis for accurate judgment of the season of tea.

The invention discloses a tea tree variety cold resistance early identification method, device, equipment, medium and product, and relates to the field of tea tree variety stress resistance identification. The method comprises the following steps: acquiring tea samples of different cold-resistant tea tree varieties in four seasons; determining a stable isotope ratio in each tea sample; a partial least squares discriminant analysis method is adopted, the stable isotope ratio in each tea sample in four seasons of the year is used as an independent variable, the cold resistance of the tea tree variety corresponding to the tea sample is used as a dependent variable, and a cold resistance quantitative prediction model is established; obtaining tea samples of the to-be-detected tea tree variety in four seasons, and determining stable isotope ratios of the to-be-detected tea tree variety in the tea samples in all seasons; and inputting the stable isotope ratio of the to-be-tested tea tree variety in the tea samples all the year round into the cold resistance quantitative prediction model to obtain the cold resistance of the to-be-tested tea tree variety. Early identification of the cold resistance of the tea tree variety can be realized.

According to various aspects of the present disclosure, a method is provided for the traceability and source identification of cosmetic-grade ethanol. The method includes the step of measuring at least two stable isotope ratios.

This invention discloses a method for determining the origin of tea based on the stable isotope ratio of EGCG monomers, belonging to the field of tea origin identification technology. It aims to solve the technical problem of insufficient accuracy in existing tea origin identification methods. The method involves measuring the overall stable isotope ratio δ in the tea sample. 13 C 茶叶 δ 15 N 茶叶 δ 2 H 茶叶 δ 18 O 茶叶 and the δ¹² value of stable isotope ratios of EGCG monomers 13 C EGCG δ 2 H EGCG and δ 18 O EGCG The preparation method of EGCG monomer involves making tea powder from tea samples, extracting and purifying epigallocatechin gallate (EGCG) monomer from the tea powder, and then determining the stable isotope ratio of the EGCG monomer. Based on the above stable isotope ratio, the origin of the tea sample is identified. This invention is mainly used for the accurate identification of tea origin, providing technical support for tea traceability and quality control.

The invention relates to the technical field of detection, and discloses a method for tracing the origin of silkworm cocoons based on a stable isotope technology in combination with a machine learning algorithm, and the method comprises the steps: (1) collecting data; (2) data preprocessing; (3) model optimization; (4) model training; and (5) producing area tracing. According to the invention, origin traceability of silkworm cocoons from different origins is realized based on isotope analysis and a machine learning algorithm. Specifically, hydrogen, oxygen, carbon and nitrogen stable isotope ratio data are combined with KNN, SVM and RF algorithms to realize rapid and high-precision source tracing of silkworm cocoon producing areas. According to the invention, by combining the advantages of various machine learning algorithms, the accuracy and reliability of silkworm cocoon origin tracing are improved.

The invention discloses a method for identifying the producing area of saffron crocus by extracting saffron crocus aldehyde and measuring the stable isotope ratio of the saffron crocus aldehyde. The invention discloses a method for extracting crocetin from saffron crocus and measuring the stable isotope ratio of carbon to hydrogen to oxygen. The method comprises the following steps: S1, determining the stable isotope ratio of carbon to hydrogen to oxygen of a crocetin standard substance by using an elemental analysis-stable isotope mass spectrometer; s2, extracting crocus sativus aldehyde from the crocus sativus sample to obtain a crocus sativus aldehyde extracting solution; s3, determining the carbon, hydrogen and oxygen stable isotope ratio of crocetin in the crocetin extracting solution by using a gas chromatography-stable isotope mass spectrometer; and S4, calibrating the carbon, hydrogen and oxygen stable isotope ratio of crocetin in the crocetin extracting solution by adopting the carbon, hydrogen and oxygen stable isotope ratio of the crocetin standard substance. The standard substance is used for calibrating the stable isotope ratio of carbon, hydrogen and oxygen of the single compound crocetin, and the method can be used for identifying the producing area of crocetin.

The invention discloses a method for monitoring carbon leakage in a carbon dioxide mineralization process by using stable isotopic tracing. The method comprises the following steps: measuring a delta 13C value of a CO2 gas source used in the carbon dioxide mineralization process; a CO2 gas source is injected into the carbon dioxide mineralization process, and then the carbon dioxide mineralization process flow is started; collecting each key point sample in the carbon dioxide mineralization process; measuring and analyzing the delta 13C value of the sample at each key point; and calculating the carbon leakage rate according to the measured delta 13C value of the sample at each key point, and evaluating the mineralization effect. According to the method, CO2 migration and leakage risks are tracked in real time by injecting CO2 with a specific carbon stable isotope ratio (delta13C) and combining on-site laser spectrum analysis and multi-isotope detection, the monitoring precision and the quantification capacity are improved, the method is suitable for a carbon dioxide mineralization utilization project, and the environmental risk is reduced.

The present application belongs to the technical field of environmental monitoring, and particularly relates to a quantitative identification method for contribution of autochthonous organic carbon of surface water. The present application constructs a water DOM source analysis method based on stable isotope ratio and three-dimensional fluorescence spectrum, comprehensively analyzes the source and characteristics of DOM, and identifies the characteristic information and contribution of autochthonous organic carbon. The three-dimensional fluorescence spectrum in the present application has the advantages of rapid detection, small sample consumption, etc., and can quickly qualitatively identify the source of DOM. The stable isotope ratio analysis in the present application can quantitatively calculate the different sources of DOM, and combined with the land use, hydrology and water environment and water quality parameters of the research area, the source and migration rule of water DOM can be more comprehensively determined. The quantitative identification method provided by the present application is more comprehensive for water DOM research, the identification system is more complete, and the tracing result is more reliable.

The application provides a method and device for determining photosynthetic rate of plant leaves based on carbon 13 isotope labeling, and belongs to the technical field of biology. 13 The application first places the leaves to be measured into an assimilation chamber and labels them with CO2, and then measures the change in C content of specific parts of the leaves before and after labeling by means of an elemental analyzer and a stable isotope ratio mass spectrometer. 13 The photosynthetic rate of the leaves in unit area and unit time can be calculated. 13 The amount of C, i.e. the photosynthetic rate. The method and device can simultaneously determine the photosynthetic rates of multiple parts of the leaves, and greatly improve the determination efficiency.

The invention discloses a reaction furnace capable of observing the change of a reaction column for element isotope analysis, which is mainly used for visualization and quantification of an oxidation-reduction process in an element-stable isotope ratio mass spectrometer and comprises a reaction furnace body, a reaction tube and an observation strip, the reaction tube is arranged in the reaction furnace body, an opening is formed in the surface of the reaction tube, a through hole is formed in the surface of the reaction furnace body, the observation strip is arranged between the through hole and the opening, the observation strip covers the through hole and the opening in a sealing manner, and the observation strip is made of a transparent material. By adopting the arrangement, the oxidation reduction process can be observed and quantified at any time during use, and the visualization and quantification of the ash content volume and the reduced copper residual degree are realized.

The invention provides a method for determining the oxygen isotope ratio of water in high-alcohol-content Baijiu, and relates to the field of stable isotope ratio mass spectrometry detection. The determination method comprises the following steps: diluting to-be-determined high-degree white spirit by using water with a known oxygen isotope ratio to obtain a diluted target spirit sample; performing equilibrium exchange reaction on 16O of water in the target wine sample and 18O of the carbon dioxide standard gas to obtain a reaction wine sample; measuring the oxygen isotope ratio of water in the reaction wine sample; and performing conversion to obtain the oxygen isotope ratio. According to the method, the high-degree white spirit is diluted with water with the known oxygen isotope ratio, the ethanol concentration is reduced to avoid interference of isotopic, and the original value is inversely calculated by combining the mass conservation principle. According to the method, tedious off-line physical separation is not needed, automatic analysis can be carried out by directly utilizing the on-line mass spectrometer, the operation process is greatly simplified, and the detection efficiency is remarkably improved while it is guaranteed that the result is accurate and reliable.

The application belongs to the field of analysis and detection, and particularly relates to a method for detecting the content of directly absorbed exogenous glycine of microorganisms in soil, which comprises the following steps: firstly, mixing a double-labeled glycine solution with soil, adding sodium laureth sulfate and chloroform for fumigation, then extracting, deriving by hydrocarbonation reaction of ethyl bromoformate, and completing the extraction of glycine in microorganisms after stable layering by using sodium bicarbonate solution; and after the extraction is cracked by a stable isotope ratio mass spectrometer, exogenous glycine and original glycine in microorganisms are distinguished by characteristic ions to be determined. The method can effectively detect the content of directly absorbed exogenous glycine of microorganisms, is simple in operation, strong in specificity, has a good linear relationship, high sensitivity and accuracy, and effectively solves the problem that the content of directly absorbed exogenous glycine of microorganisms cannot be directly quantified. Thus, the direct utilization pathway of soil microorganisms to exogenous amino acid substances is quantitatively judged.

The application belongs to the field of analysis and detection, and particularly relates to a method for detecting the content of directly absorbed exogenous glycine of microorganisms in soil, which comprises the following steps: firstly, mixing a double-labeled glycine solution with soil, adding sodium laureth sulfate and chloroform for fumigation, then extracting, deriving by hydrocarbonation reaction of ethyl bromoformate, and completing the extraction of glycine in microorganisms after stable layering by using sodium bicarbonate solution; and after the extraction is cracked by a stable isotope ratio mass spectrometer, exogenous glycine and original glycine in microorganisms are distinguished by characteristic ions to be determined. The method can effectively detect the content of directly absorbed exogenous glycine of microorganisms, is simple in operation, strong in specificity, has a good linear relationship, high sensitivity and accuracy, and effectively solves the problem that the content of directly absorbed exogenous glycine of microorganisms cannot be directly quantified. Thus, the direct utilization pathway of soil microorganisms to exogenous amino acid substances is quantitatively judged.

The invention provides a method for determining the ratio of non-exchangeable hydrogen stable isotopes in grain starch, which is suitable for food stable isotope analysis. The method comprises the following steps: 1) crushing a sample; 2) removing fibers, proteins and moisture; 3) gelatinizing the sample by using a reagent containing exchangeable hydrogen to realize isotope exchange balance; 4) dissolving a starch standard substance and gelatinizing; 5) drying; (6) determining the stable hydrogen isotope ratio of the sample to the standard substance by using a high-temperature cracking / element analysis-stable isotope ratio mass spectrum; and 7) correcting according to the standard curve to obtain the isotope ratio of the non-exchangeable hydrogen in the starch. The method can be used for accurately measuring the ratio of the non-exchangeable hydrogen in the grain starch and eliminating the interference of moisture on hydrogen isotope characteristics, and is suitable for research and application of traceability of grain production places.

The invention relates to a method for identifying tea leaves in different seasons, and belongs to the technical field of tea leaf quality detection. Existing tea season identification mostly depends on sensory or single component analysis, and is high in subjectivity and insufficient in accuracy. The method comprises the following steps: collecting a tea sample, detecting stable isotope ratios of delta C and delta 15N and organic component contents of EGC, EGCG, ECG and CAF in the tea sample, respectively substituting the data into linear discrimination models in spring, summer and autumn, calculating to obtain numerical values of Y spring, Y summer and Y autumn, comparing the three values, and determining the season corresponding to the maximum numerical value as the season to which the tea sample belongs. According to the method, multiple indexes are combined with the linear discrimination model to realize objective discrimination of tea seasons, the method can be used for scenes such as tea quality control, market supervision and tea traceability, and a scientific basis is provided for accurate judgment of tea season sources.

The invention provides a method for continuously testing three stable carbon isotopes in soil, and belongs to the technical field of soil detection. The pretreatment process of stable carbon isotope testing of three carbon forms (carbonate inorganic carbon, soluble organic carbon and non-soluble organic carbon) of soil is simplified and integrated, then the same stable isotope ratio mass spectrometer is externally connected with a multipurpose online gas preparation and introduction device and an element analyzer, and the external connection sequence is controlled; and efficient and continuous testing of three carbon isotopes is realized. Compared with a traditional method in which single carbon forms are respectively treated and independently detected, the method has the advantages that the time cost of sample pretreatment and instrument analysis is reduced, error accumulation caused by sample transfer and multiple pretreatment is avoided, and the detection result is more accurate.

The invention relates to the technical field of environmental analysis and detection, and provides a method for determining the monomer hydrocarbon stable isotope ratio of atrazine. The method comprises the following steps: by taking normal hexane as an extracting agent, preparing to-be-detected arterzine liquid through liquid-liquid extraction; detecting the liquid to be detected by adopting gas chromatography-stable isotope ratio mass spectrometry to obtain a carbon stable isotope ratio and / or a hydrogen stable isotope ratio; whether the atrazine is transformed or not is further judged according to a test result, so that a transformation mechanism of the atrazine is clarified. The invention provides a novel method for identifying contribution of an atrazine degradation process, the problems of insensitivity, inaccuracy and the like caused by observing the change of a substrate removal rate by quenching an oxidizing agent in a traditional method are solved, and a foundation is laid for contribution identification and mechanism research in the atrazine degradation reaction process.

The invention belongs to the technical field of stable isotope analysis, and discloses a method for determining the stable isotope ratio of caffeine hydrogen in tea leaves. According to the method, caffeine in the tea leaves is extracted through the processes of water extraction, liquid-liquid extraction and the like, a large number of impurity components are effectively removed, the GC-IRMS with an online high-temperature cracking reaction device is used for carrying out caffeine separation and hydrogen stable isotope ratio determination on the caffeine extract, and the method has the advantages of being easy and convenient to operate, high in efficiency and good in repeatability; technical support and scientific basis are provided for tea producing area traceability by using a monomer isotope technology.