15 results about "Comprehensive two-dimensional gas chromatography" patented technology

The invention discloses a quality mining and evaluation method of a wolfberry characteristic flavor nourishment, and relates to the technical field of food quality analysis and sensory evaluation, and the method comprises the following steps: S1, carrying out non-targeted analysis on the wolfberry characteristic flavor nourishment by adopting headspace solid phase microextraction in combination with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry, and obtaining original abundance data of the volatile compound. According to the quality mining and evaluation method for the Chinese wolfberry characteristic flavor nourishment, accurate identification and quantitative evaluation of key flavor substances in the Chinese wolfberry characteristic flavor nourishment are realized by establishing a flavor contribution potential index model and combining a dual verification mechanism. According to the method, the limitation that only a single chemical component is concerned or actual sensory experience is ignored is solved, and the accuracy and reliability of flavor component screening are improved by integrating multi-dimensional parameters such as instrument response intensity, human olfaction threshold and matrix release characteristics and through cross validation of a gas chromatography-olfaction technology and a standard substance addition experiment.

The present application relates to the technical field of Fischer-Tropsch synthesis wax analysis chemistry, and in particular to a method for detecting oxygen-containing compound components in Fischer-Tropsch synthesis wax by using solid-phase microextraction and comprehensive two-dimensional gas chromatography-mass spectrometry. The method comprises the following steps: first, performing solid-phase microextraction on a to-be-tested wax sample to obtain an extract rich in oxygen-containing compound components; and then using comprehensive two-dimensional gas chromatography-mass spectrometry to qualitatively determine the composition of the oxygen-containing compound components contained in the extract. In the method, the content of the oxygen-containing compound components is less than or equal to 7 wt% based on the total weight of the Fischer-Tropsch synthesis wax. The method has the characteristics of high throughput, high sensitivity and high accuracy, and solves the problems of difficult analysis and separation and difficult qualitative determination of alcohol, aldehyde, ketone, acid, ester and other oxygen-containing compound components in Fischer-Tropsch synthesis wax.

The invention provides a method for analyzing characteristic flavor substances in table vinegar and application of the method, and relates to the technical field of food flavor detection.The method comprises the steps that volatile compounds in the table vinegar are determined through comprehensive two-dimensional gas chromatography-smelling-mass spectrometry, and the characteristic flavor compounds are determined; the content of organic acid and reducing sugar in the table vinegar is determined by high performance liquid chromatography, and the content of characteristic taste compounds in the table vinegar is determined. According to the method, the volatile compounds in the table vinegar are determined by adopting comprehensive two-dimensional gas chromatography and smelling mass spectrometry, and the characteristic odor compounds are positioned and discriminated; the content of organic acid and reducing sugar in the table vinegar is determined by adopting a high performance liquid chromatograph, the content of characteristic taste compounds in the table vinegar is positioned, and discrimination is implemented. According to the method provided by the invention, the characteristic odor substances in the table vinegar can be rapidly and accurately detected, and meanwhile, the taste characteristics of the table vinegar can be objectively reflected.

The invention discloses a method for analyzing chlorinated paraffin in an environment or food sample. Comprehensive two-dimensional gas chromatography-electron capture negative chemical ion source quadrupole mass spectrometry is used for analyzing short-chain and medium-chain chlorinated paraffin in an environment or a food sample. According to the technology, co-outflow components in a complex matrix can be effectively distinguished through orthogonal separation in a unit mass resolution mode, and characteristic ion response information of a target chlorinated paraffin homologue group (C10-C17) can be rapidly and accurately obtained. The detection limit of the method can reach a nanogram / gram (ng / g) level, and the method has high sensitivity, accuracy and precision; according to the method, the conventional C10-C17 chlorinated paraffin in the environment or food sample can be comprehensively covered and accurately quantified, and the actual demand on comprehensive analysis of short-chain and medium-chain chlorinated paraffin in the current environment and food monitoring is effectively met.

The invention provides an organic matter rapid screening and peak generation stability verification method based on a comprehensive two-dimensional gas chromatograph-mass spectrometer. The method comprises the following steps: acquiring sample files of at least two samples; generating a grid file corresponding to each sample file, wherein a first grid of the grid file is used for recording a data condition of a corresponding position in the sample file; combining the grid files to obtain an aggregated grid file, wherein the aggregated grid file comprises a plurality of second grids; target grids are screened in the aggregation grid file, organic matter data of the target grids are obtained, the target grids are second grids with the detection probability larger than the preset probability, and the detection probability is used for representing the probability that the organic matter has features in the corresponding positions in the sample files. According to the method, the organic matter data of different samples are merged, and the target grid is screened according to the data condition of the second grid, so that batch processing of the organic matter data of multiple samples is realized, the processing time is shortened, and the efficiency is improved.

This invention discloses a wastewater source tracing detection method based on full two-dimensional gas chromatography-mass spectrometry, belonging to the field of environmental monitoring technology. The method includes: establishing a source-end transformation fingerprint chain library based on the connection relationships between parent peak clusters, associated peak clusters, and transformation peak clusters in the peak cluster families corresponding to the source-end sample sequence; obtaining a receptor peak cluster family table; performing a chain comparison between the source-end transformation fingerprint chain library and the receptor peak cluster family table to determine candidate source peak cluster families and overlapping peak cluster families; performing peak cluster family exclusion stripping to generate a confirmed source portion and a set of residual unexplained peak cluster families; merging the residual unexplained peak cluster family set for unknown sources to form an unknown transformation chain; and combining this with the confirmed source portion to output the wastewater source tracing detection results. This invention improves the completeness, specificity, and interpretability of wastewater source tracing detection results.

The application discloses a fuel property prediction method and device, equipment and a storage medium, and the method comprises the following steps: analyzing a to-be-tested fuel sample by means of a two-dimensional gas chromatograph to obtain hydrocarbon composition data of the to-be-tested fuel sample, inducing a plurality of key chemical component variables and constructing a component feature vector; performing standardization processing and principal component analysis on the component feature vector to obtain principal components meeting preset conditions and calculating a principal component score vector; inputting the principal component score vector into a trained nonlinear regression prediction model to obtain a predicted value of a physical and chemical property of the to-be-tested fuel sample; wherein the nonlinear regression prediction model comprises linear terms, square terms and interaction terms of the principal component score vector; wherein the square terms and the interaction terms are used to represent the nonlinear effect of the components on the physical and chemical property and the synergistic effect between the components. Thus, the problem of large fuel sample consumption and long test period can be solved, and the fuel property can be accurately predicted.

A method for studying the distribution of aromatics in diesel fuel using two-dimensional gas chromatography (GC) comprises the following steps: S1: Separating the sample to be tested using a GC modulation system to obtain a GC chromatogram; S2: Identifying the detailed compositional information of the sample using the GC chromatogram obtained in step S1, and classifying it into different groups of compounds based on their polarity; S3: Applying the principle of simulated distillation using GC to obtain the distillation curves of the different groups of compounds obtained in step S2; S4: Analyzing the changes in mass yield of different groups of compounds within different fractions of the distillation curves obtained in step S3 to study the component variation patterns during diesel fuel processing and conversion. This invention enables the study of component variation patterns during diesel fuel processing and conversion based on the changes in mass yield of different groups of compounds within different fractions.

The invention discloses a system and a method for realizing two-dimensional and comprehensive two-dimensional gas chromatography, the system comprises a sample injection port EPC system, a four-way valve and a three-way high-frequency electromagnetic valve, one end of a carrier gas pipeline of the sample injection port EPC system is communicated with one end of a sample injection port, the other end of the sample injection port is communicated with one end of a first chromatographic column through a pipeline, and the other end of the first chromatographic column is communicated with the other end of a second chromatographic column through a pipeline; the other end of the first chromatographic column is communicated with a first branch of a four-way joint through a pipeline, a second branch of the four-way joint is communicated with one end of a second damping column through a pipeline, a third branch of the four-way joint is communicated with one end of a first damping column through a pipeline, and a fourth branch of the four-way joint is communicated with one end of a second chromatographic column through a pipeline; and the other end of the second chromatographic column is communicated with the detector through a pipeline. According to the chromatographic system provided by the invention, two independent separation systems are arranged, a two-dimensional gas chromatography or comprehensive two-dimensional gas chromatography test mode can be flexibly selected as required, and the operation is flexible.

The method comprises the following steps: putting a to-be-detected gasoline sample, a potassium bromate-potassium bromide aqueous solution and an inorganic acid aqueous solution into a closed container for reaction to obtain a pretreated gasoline sample; the comprehensive two-dimensional gas chromatograph is adopted for detecting the content of saturated hydrocarbon, aromatic hydrocarbon and olefin in the pretreated gasoline sample, the saturated hydrocarbon, the olefin and the aromatic hydrocarbon can be separated and measured, and the content of gasoline family components can be measured; meanwhile, the measuring speed is high, and the accuracy is high.

The invention discloses a traditional Chinese medicinal material intelligent identification method and system based on cross-modal contrast learning and adaptive attention fusion. The method comprises the following steps: acquiring image data, smell data and text description data of a traditional Chinese medicinal material sample, wherein the smell data can be acquired through laboratory equipment such as an electronic nose, a GC-MS (Gas Chromatography-Mass Spectrometer), a GC-IMS (Gas Chromatography-Mass Spectrometer) and the like or a low-cost sensor array; each modal feature is extracted through encoders such as a visual Transform, a time sequence Transform or a convolutional neural network, a BERT and the like; infoNCE contrast learning is adopted to realize cross-modal semantic alignment of the three-modal features; self-adaptive weighted fusion is carried out through combination of a cross-modal attention mechanism and confidence estimation of uncertainty perception; and multi-task combined learning based on prototype learning predicts the types, the production places and the quality grades of the medicinal materials at the same time. The method further introduces a modal dropout training strategy and a missing modal dynamic completion mechanism to enhance the robustness of the system. According to the method, the three heterogeneous modalities of the image, the smell and the text are deeply fused, various smell acquisition devices are supported, and the method has the advantages of high accuracy, high interpretability and modal loss robustness and is suitable for laboratory high-precision analysis and on-site rapid detection.

This invention provides a method for identifying crude oil types based on two-dimensional gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). The method includes: dissolving the crude oil sample to be identified using a diluent, then adding a 5α-androstane standard to the system to obtain the crude oil sample; performing chromatographic analysis of the crude oil sample using GC-TOF-MS; denoting the ratio of the sum of the weights of n-alkanes, isoalkanes, monocyclic alkanes, bicyclic alkanes, tricyclic alkanes, tetracyclic alkanes, and pentacyclic alkanes in the crude oil sample to the weight of the crude oil sample to be identified as S; denoting the ratio of the sum of the weights of monocyclic alkanes, bicyclic alkanes, tricyclic alkanes, tetracyclic alkanes, and pentacyclic alkanes in the crude oil sample to the weight of the crude oil sample to be identified as N; and identifying the type of crude oil sample based on the ratio of S to N. This method provides a new approach for the precise identification of naphthenic crude oil and the estimation of naphthenic crude oil reserves.

The invention discloses a multi-dimensional extraction and analysis method of tea aroma in the technical field of food chemistry and analytical chemistry. The method comprises the following steps: firstly, mixing dry tea powder with ultrapure water, oscillating in a constant-temperature water bath, and standing to release fragrance; filling a thermal desorption tube with a specially-made silicon-based mesoporous titanium dioxide-zirconate hybrid nanocage, and adsorbing and enriching aroma components in headspace gas; after adsorption is completed, a thermal desorption pipe is connected into a thermal desorption instrument, and components subjected to thermal desorption are injected into a comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry system for analysis after being focused by a cold trap; and finally, processing data by using professional software, extracting multi-dimensional reserved information and mass spectrum characteristics of aroma active compounds, and constructing a four-dimensional fingerprint spectrum for finely characterizing the aroma of the tea leaves. The method disclosed by the invention realizes efficient enrichment, high-resolution separation and multi-dimensional accurate characterization of tea aroma, and is high in sensitivity and good in reproducibility.

The invention relates to a general diesel fuel construction method and system capable of reproducing engine performance. The method comprises the following step: analyzing the components and content of target diesel oil by adopting comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry and nuclear magnetic resonance technologies. On the basis of n-hexadecane, isohexadecane and 1-methylnaphthalene, a component database is combined, and a model Sur0 is preliminarily constructed. Iterative correction is carried out through deviation functions of three levels of physicochemical characteristics, atomization characteristics and combustion emission characteristics. In each step, the calculation deviation is compared with a preset threshold value, the component proportion is adjusted, optimization models Sur1 and Sur2 are obtained in sequence, and finally a comprehensive alternative fuel model Sur3 capable of accurately simulating target diesel oil is obtained, so that the injection atomization characteristic, the ignition and combustion characteristic, the performance index and various emission characteristics of actual fuel in a cylinder are accurately reproduced; therefore, the method can be used for accurately simulating flow, mixing and combustion characteristics of the diesel engine.