11 results about "Stable Isotope Labeling" patented technology

The present application relates to a kind of detection methods of isotopic abundance in acetic acid, comprising the following steps: stable isotope labeled acetic acid is decomposed under vacuum and high temperature conditions, generates stable isotope labeled methane or carbon dioxide, can determine 13 C labeled in carboxyl site acetic acid CH3 13 COOH in 13 C isotopic abundance, 13 C labeled in methyl site acetic acid 13 CH3COOH in 13 C isotopic abundance, 18 O labeled acetic acid CH3C 18 O 18 OH in 18 O isotopic abundance, methyl deuterium isotopic abundance in deuterium labeled methyl site acetic acid CD3COOH;Compared with prior art, the present application has the advantages that the isotopic abundance in acetic acid labeled by stable isotope in different sites is detected, can be used for deuterium, 13 C or 18 O labeled acetic acid isotopic abundance determination, test data accuracy and precision etc.

The application discloses a method for distinguishing the carbon assimilation pathway type characteristics of methanotrophs. 13 CH4 stable isotope labeling and collecting single-cell Raman full spectrum data; based on the PCA-LDA discriminant model of the reference strains 13 CH4 labeled single-cell Raman full spectrum data to establish a PCA-LDA discriminant model; a plurality of single-cell Raman full spectrum data of a to-be-tested methanotroph sample are input into the previously established PCA-LDA discriminant model, the corresponding I-type or II-type prediction category of each single-cell Raman spectrum is obtained, and it is determined that the to-be-tested sample is closer to the carbon assimilation pathway characteristics of I-type methanotrophs or the carbon assimilation pathway characteristics of II-type methanotrophs. The method can distinguish different carbon assimilation pathway types of methanotrophs.

The application belongs to the technical field of stable isotope labeled compound preparation, and specifically discloses a carbon 13 labeled carbonate and a one-step preparation method thereof. Under an inert atmosphere, carbon 13 urea is mixed with water to obtain a carbon 13 urea solution; metal hydroxide is mixed with water to obtain a metal hydroxide dispersion; then under the inert atmosphere, the carbon 13 urea solution is added dropwise into the metal hydroxide dispersion to perform a reaction, and a slurry containing carbon 13 labeled carbonate is obtained; after post-treatment, the carbon 13 labeled carbonate is obtained. The application can be widely adapted to various metal hydroxide raw materials, realize the large-scale preparation of a series of carbon 13 labeled carbonate products, and efficiently realize the high-value utilization of low-abundance unqualified carbon 13 urea, effectively solving the industry pain points such as large carbon 13 abundance loss, complicated preparation steps, serious equipment corrosion and easy pollution by environmental CO2 in the existing process.

A method for synthesizing a stable isotope-labeled toltrazuril-D3 belongs to the field of organic synthesis technology. This method uses methylamine hydrochloride-D3 as the stable isotope labeling source, reacting it with p-trifluoromethylthiophenol and 1-chloro-2-methyl-5-nitrobenzene as starting materials, undergoing sequential condensation and reduction to obtain an aminodiphenyl ether intermediate. Simultaneously, methylamine hydrochloride-D3 reacts with sodium cyanate to generate methylurea-D3, which then reacts with carbonyl diimidazole to obtain an activated intermediate. Finally, the aminodiphenyl ether intermediate condenses with the activated intermediate, followed by base-catalyzed cyclization to obtain the target product, toltrazuril-D3. This invention features a rationally designed synthetic route, readily available raw materials, mild reaction conditions, simple operation, and easy product separation and purification. The obtained product achieves a chemical purity and isotope abundance of over 99%.

This invention discloses a method for identifying the effectiveness of water consumption through transpiration in fruit trees, belonging to the technical fields of agricultural water conservation and fruit tree cultivation. This invention first completes the grading and classification of branches, and then stabilizes representative branches... 13 C30 isotope labeling experiments were used to obtain basic data on assimilate transport and distribution. Combined with source-sink theory and a three-dimensional function-structure model of plants, the contribution of different branches to fruit growth was calculated, thereby classifying the transpiration water use efficiency level and ultimately guiding fruit tree pruning and water management. This invention solves the problem in existing technologies where the spatial heterogeneity of the canopy is ignored, leading to difficulties in defining redundant growth. It can significantly reduce ineffective and inefficient transpiration water use, improve water use efficiency, and simultaneously improve the canopy light environment, enhancing fruit quality and uniformity. It is suitable for water-saving cultivation management in various orchards.

This invention provides a method for analyzing the methane source in a soil-trunk continuum based on stable isotope tracing, belonging to the field of ecological environment monitoring and stable isotope tracing technology. This invention injects stable isotope-labeled methane gas into deep soil, giving soil-derived methane a identifiable tracer signal. Combined with stratified sampling of soil profiles at different depths and simultaneous multi-height monitoring of tree trunks, the migration process of methane from soil to tree trunks can be continuously tracked. Compared to existing methods that rely solely on the correlation between methane concentration and flux in tree trunks and soil for inference, this invention provides more direct source evidence. Furthermore, this invention uses artificially enriched stable isotope-labeled signals instead of natural background isotope signals as the primary criterion, effectively reducing the interference of fluctuations in natural isotope abundance signals and changes in environmental factors on the results, thereby improving the reliability of methane source identification in tree trunks.

The present application relates to a kind of neuroendocrine metabolite detection kit and its detection method, it is related to biological detection technical field.The kit includes including calibration, high-value quality control, low-value quality control, internal standard solution and precipitant.The detection method related to the present application includes the following steps: S1, sample pretreatment: S2, machine detection;S3, calibration curve drawing;S4, quality control data analysis;S5, sample data analysis.The present application detects accurately, error is small, simple operation avoids the cross reaction caused by structural analogue, ensures the authenticity of detection result.In the accuracy, mass spectrometry uses stable isotope-labeled internal standard to carry out absolute quantification, can accurately compensate the loss and matrix effect in sample pretreatment process, to provide highly accurate and repeatable quantitative result, provides important basis for neuroendocrine tumor screening and auxiliary diagnosis of depression, Parkinson's disease and the like.

This invention belongs to the field of environmental analytical chemistry and mass spectrometry, specifically relating to a targeted-non-targeted synergistic analysis method for aldehyde compounds based on stable isotope-labeled APMP derivatization reagents and a dual-library system. This method synthesizes d0 and d3 isotope-labeled APMP reagents to derivatize aldehyde compounds, and combines this with liquid chromatography-mass spectrometry (LC-MS) to achieve highly sensitive detection. Furthermore, a self-built dual-library system containing both derivatized and non-derivatized libraries is constructed, combining targeted quantification and non-targeted screening to achieve synergistic identification and quantitative analysis of known and unknown aldehyde compounds. Isotope internal standard correction and library matching verification improve the accuracy and reliability of the detection. This invention overcomes the limitations of traditional methods in terms of limited detection coverage and insufficient non-targeted quantitative analysis capabilities, making it suitable for high-throughput analysis of aldehyde compounds in complex environmental samples.

This invention provides 13 High-abundance CO was prepared by CuO catalytic oxidation. 13 This invention relates to a CO2 apparatus and method, belonging to the field of stable isotope-labeled compound preparation technology. The apparatus described in this invention is an integrated unit comprising a feed gas supply unit, a fixed-bed reaction unit, a cryogenic collection unit, a partial pressure purification unit, and a tail gas treatment unit connected in series. The fixed-bed reaction unit includes a fixed-bed reactor, a heater, and a temperature sensor. This invention utilizes high-temperature calcined modified CuO catalyst particles, combined with a composite bed structure design of "quartz wool-quartz sand-catalyst-quartz sand," significantly improving conversion efficiency and selectivity; optimizing the purification process, achieving product quality that meets high-end application standards; featuring a novel apparatus design with greatly improved sealing and stability; simple and controllable operation, facilitating industrial scale-up; and being green, safe, and environmentally friendly, aligning with industrial development trends.

The application discloses a construction method and quantitative analysis method of a stable isotope labeled internal standard, a working solution, mass spectrum detection after obtaining a deuterium hydrogen exchange reaction product of a target compound, screening deuterium isotope between the target compound and meeting Δm >= 3 as an internal standard candidate component, chromatographic detection of the target compound and the internal standard candidate component, if the retention time difference Δt of the two is < 0.01 min, it is determined that the internal standard candidate component can be used as a stable isotope labeled internal standard, if the retention time difference Δt of the two is >= 0.01 min, the hydrogen deuterium exchange reaction condition is adjusted, and the above steps are re-executed until the stable isotope labeled internal standard with the retention time difference Δt < 0.01 min of the target compound is obtained. The stable isotope labeled internal standard constructed by the application can avoid natural isotope peak interference, the chromatography of the internal standard and the analyte meets the co-flowing requirement of Δt < 0.01 min, and is helpful to improve the effectiveness of quantitative correction.

This invention provides a mass spectrometry method for determining the 42 / 40 ratio of β-amyloid protein in human plasma, including using¹ 5 Using intact Aβ42 and Aβ40 proteins labeled with N stable isotopes as internal standards, plasma samples were extracted and purified using immunoprecipitation. Characteristic peptides were then generated through Lys-N proteolysis, and finally, targeted quantitative analysis was performed using liquid chromatography-tandem mass spectrometry. The characteristic peptide of Aβ42 is Aβ28-42 KGAIIGLMVGGVVIA; the characteristic peptide of Aβ40 is Aβ28-40 KGAIIGLMVGGVV. Compared to intact proteins, the characteristic peptides in this invention are less prone to aggregation and exhibit higher ionization efficiency in mass spectrometry, demonstrating excellent specificity, repeatability, and sensitivity, providing a reliable basis for the diagnosis of Alzheimer's disease.