32 results about "Mass spectral library" patented technology

A method for reproducibly analyzing mass spectra from different sample sources is provided. The method deconvolutes the complex spectra by collapsing multiple peaks of different molecular mass that originate from the same molecular fragment into a single peak. The differences in molecular mass are apparent differences caused by different charge states of the fragment and / or different metal ion adducts and / or reactant products of one or more of the charge states. The deconvoluted spectrum is compared to a library of mass spectra acquired from samples of known identity to unambiguously determine the identity of one or more components of the sample undergoing analysis.

Microbes in a sample are identified by calculating similarities between a mass spectrum of the sample and reference mass spectra in a spectral library. The spectral library is divided into a hierarchy of sub-libraries where each sub-library contains reference mass spectra of microbes which are statistically the most prevalent in the samples, but are not included in other sub-libraries and all additional reference mass spectra in the library that have substantial similarity to the reference mass spectra of these microbes. Only if the search in a sub-library does not provide a hit with sufficient certainty of identification, is the search carried out in sub-libraries of higher stages.

A method of acquiring and compiling data obtained on a mass spectrometer system, comprises: (a) generating a multiplexed mass spectrum comprising a superposed plurality of product-ion mass spectra comprising a plurality of product-ion types, each product-ion mass spectrum corresponding to fragmentation of a respective precursor-ion type, each precursor-ion type and each product ion type having a respective mass-to-charge (m / z) ratio; (b) decomposing the multiplexed product-ion mass spectrum so as to recognize relative abundances of previously-observed product-ion mass spectra within the multiplexed product-ion mass spectrum, the decomposing employing a mass-spectral library having a plurality of entries corresponding to respective product ion mass spectra previously-observed on said mass spectrometer system; (c) recognizing an additional contribution to the multiplexed mass spectrum that is neither attributable to random variation nor to any previously-observed product-ion spectrum; and (d) storing at least one new entry in the mass-spectral library relating to the recognized additional contribution.

A method of acquiring and interpreting data using a mass spectrometer system and a local mass spectral library comprises: (a) generating a multiplexed mass spectrum, the multiplexed mass spectrum comprising a superposition of a plurality of product-ion mass spectra comprising a plurality of product-ion types, each product-ion mass spectrum corresponding to fragmentation of a respective precursor-ion type; (b) recognizing a respective set of two or more product-ion types corresponding to each of one or more of the product-ion mass spectra by recognizing correlations between the elution profiles of said two or more product-ion types corresponding to each said respective set; and (c) determining if each recognized set of two or more product-ion types corresponds to a product-ion mass spectrum previously observed using said mass spectrometer system by comparing the m / z ratios of the product ion types to information in at least one entry of the local mass spectral library.

The invention discloses a qualitative and quantitative analysis method of elemental sulfur in light petroleum fractions and light petroleum products, wherein the gas chromatography / mass spectrometry is adopted in the method. In the qualitative method, a scanning mode is adopted to analyze various samples, and the qualitative analysis is performed by utilizing the analysis of the obtained mass spectrum, combining the standard mass spectral library search and comparing with the retention time of an elemental sulfur guide sample. In the quantitative method, the ion monitoring mode is adopted anda standard curve is established to perform quantitative analysis, wherein a sample to be tested does not require pretreatment and can be directly sampled for analysis. The qualitative and quantitative analysis method has the advantages of wide linear range, low detection limit, high precision, wide coverage of samples, no interference in analysis, short analysis time and is simple in operation.

The invention discloses a method for rapidly screening highly-concerned chemicals in surface water and soil. The method comprises the steps of screening a highly-concerned chemical list, grouping substances, optimizing mass spectrum conditions and chromatographic conditions, constructing a mass spectrum library and rapidly screening the highly-concerned chemicals. According to the method, samplesin surface water and soil are rapidly screened by adopting ultra-high performance liquid chromatography-quadrupole rod / electrostatic field orbitrap high-resolution mass spectrum, and based on accuratemass number, retention time, characteristic fragments and isotope distribution proportion, the samples are searched and matched with a mass spectrum library of highly-concerned chemicals for rapid qualitative analysis. A screening result can be obtained within 70min, the sample detection and treatment time is greatly shortened, the detection efficiency is improved, and technical support is provided for risk assessment and risk management of highly-concerned chemicals.

The invention provides a method for realizing accurate identifying of a compound and screening of a differential component through automatic analysis of a complicated sample GC-MS, and belongs to thegas chromatography-mass spectrum combined data analysis. The method comprises the following steps: firstly, performing automatic extraction on a chromatographic peak under TIC and EIC, then determining an analysis range of each TIC chromatographic peak, and looking up EIC chromatographic peak information within the analysis range; clustering according to the EIC chromatographic peak information, and acquiring a representative chromatography contour spectrogram of each cluster; after screening, constructing an initial chromatography spectrogram matrix, performing optimized analysis on the initial chromatography spectrogram matrix by using a corrected multivariate curve resolution-alternating least square method, and acquiring the chemical components under each TIC chromatographic peak; andimporting a mass spectrum spectrogram of each chemical component obtained by analysis into a mass spectrum library for automatically matching the compound, and completing compound intelligent accurateidentification of a single sample GC-MS. The method has a good application value in the fields related to a GC-MS technology, such as scientific research, detection, and industrial application.

At least one product ion mass spectrum produced by a tandem mass spectrometer is received. A chemical structure of a compound that corresponds to the at least one product ion mass spectrum is received. One or more elemental compositions are assigned to at least one peak in the at least one product ion spectrum based on the chemical structure using the processor. At least one elemental composition of the one or more assigned elemental compositions is selected for the at least one peak using the processor. The mass of the at least one peak is converted to the mass of the selected at least one elemental composition using the processor, producing a product ion mass spectrum with higher mass accuracy.

The invention discloses a quantitative method for detecting small amount of organic additives in electrolyte by GC-MS (Gas Chromatography-Mass Spectrometer). The quantitative method comprises the following steps: preparing a standard solution, measuring the standard solution in an SCAN mode, determining characteristic quantitative and qualitative ion peaks of each additive in the standard solution, and establishing a mass spectrum library of each additive; determining a standard solution in an SIM mode according to the characteristic quantitative and qualitative ion peaks of each additive, anddrawing a standard curve according to the content and peak area of the standard solution; taking dichloromethane as a diluent to dilute a to-be-detected electrolyte sample; testing a to-be-tested electrolyte sample by adopting an SCAN mode, and carrying out qualitative treatment on the additives; and testing the to-be-tested electrolyte sample by adopting an SIM mode, and quantifying the additives. According to the method, the organic additive in the lithium ion battery electrolyte is analyzed by adopting the newly built mass spectrum library of the common electrolyte additive, and the qualitative result is high in accuracy. Under the qualitative condition, the quantitative result with higher accuracy is obtained by utilizing the SIM mode, and the specific performance of the lithium ion battery is favorably improved.

The invention relates to the identification of substance ions, which are usually generated by electro spray ionization after separation by liquid chromatography or capillary electrophoresis, with the help of libraries with mass spectra. The substance ions are frequently formed not only in a protonated (or deprotonated) form but also as adducts with cations or anions, a fact which complicates identification. The invention involves making identification more accurate by additionally carrying out a determination of the most probable molar mass with the help of adduct patterns.

The invention discloses a quality stability testing method for tipping paper for cigarettes. The testing method includes the steps: (1) taking a sample to be tested, cutting the sample to be tested into the size of 0.5-1.5mm<2>, and balancing the sample to be tested for 20-25 hours under the conditions of 23+ / -1 DEG C and the relative humidity of 50+ / -2%; (2) placing the tipping paper sample intoa volumetric flask after constant temperature and humidity treatment in the step (1), adding dichloromethane according to the volume mass ratio of 15-25mL:1g, sequentially performing vibration for 25-35 minutes at the frequency of 100-200r / min, ultrasonic treatment for 15-25 minutes and standing for 5-15 minutes, taking upper extracting solution, filtering the upper extracting solution by a 0.45 micrometer organic phase filter membrane, and taking filtrate as an analysis sample; (3) analyzing the analysis sample by a gas chromatograph-mass spectrometer, retrieving a chromatogram by an NIST11 standard mass spectra library, performing qualitative analysis by matching degree higher than or equal to 80%, taking integral values of chromatographic peak area as qualitative results, and comparingdifferential substances in different samples. Change of easily separated substances inside the tipping paper can be tested and analyzed, and the quality stability of the tipping paper for the cigarettes is controlled.

The invention discloses an extraction and purification method of a grape aromatic glycoside and a library building, identification and quantification method thereof. The extraction and purification method comprises the steps of selecting and peeling grape fruits, carrying out extraction, separation and purification of a terpene aromatic glycoside, building a terpene aromatic glycoside mass spectral library, performing LC-MS analysis of the terpene aromatic glycoside, using the terpene aromatic glycoside mass spectral library, and performing qualitative and quantitative analysis of the terpenearomatic glycoside. The extraction and purification method is low in cost and high in extraction efficiency, and the precision and reliability of research are guaranteed through system matching establishment of the method. The methods established by the research are simple and feasible in actual analysis, and have good popularization and application values.

A method, mass spectrometer and computer readable medium for acquiring mass spectral data; comprising acquiring mass spectral data in a raw profile mode; selecting a relevant time window for presence of compounds of interest; performing multivariate statistical analysis of mass spectral raw profile mode data in a time window to determine the number of compounds present; computing a pure profile mode mass spectra for all compounds of interest corresponding to their respective separation time profiles or time locations; searching a mass spectral library for the identification of the compounds; and adding the correctly identified compounds and corresponding profile mode mass spectra to existing mass spectral library and / or newly created profile mode mass spectral library. Implementation can be on a server located amongst a network, such as the internet, of computers, devices, and MS instruments. Users are exposed to advertising relevant to the compounds analyzed and can obtain subscriptions to library updates.

The invention discloses a method for detecting 11 kinds of pigments in reconstituted tobacco leaves for tobacco, which comprises the following steps: 1) establishing the high-resolution mass spectrum library information of 11 kinds of pigments by using double ternary high-performance liquid chromatography and high-resolution mass spectrometry, and the high-resolution mass spectrometry Database information includes pigment name, retention time, [M+H] + and [M‑2H] 2‑ Accurate mass number of ions and accurate mass number of characteristic fragment ions; 2) Pretreatment of reconstituted tobacco leaves for the tobacco to be tested: the reconstituted tobacco leaves for the tobacco to be tested are extracted with a solvent to obtain the liquid to be tested. The invention has the advantages of simple operation, quick detection and high sensitivity, and can be applied to daily detection of reconstituted tobacco leaves in cigarettes.

The invention discloses a method for qualitatively and quantitatively analyzing hydrocarbon components in aromatics extraction solvent sulfolane by adopting the gas chromatography / mass spectrometry coupling technology. In the method, the qualitative method is as follows: adopting the scanning mode to analyze the hydrocarbon components in the sample and determining the structures of the hydrocarbon components in accordance with the obtained mass spectrogram, in combination with the standard mass spectral library search and in contrast to the retention time of the guide samples of the hydrocarbon components; and the quantitative method is as follows: adopting the scanning mode, taking normal heptane or normal octane as an internal standard substance and obtaining the contents of the hydrocarbon components according to the relative volume correction factors and peak areas of the hydrocarbon components and the peak area of the internal standard substance. The method has the beneficial effects of high accuracy, low limit of detection, no interference with quantitative analysis, short analysis time, no need for pretreatment of the sample to be detected and simpleness and convenience in operation.

The invention provides a method for realizing accurate compound identification and differential component screening by GC-MS automatic analysis of complex samples, which belongs to gas chromatography-mass spectrometry data analysis. Firstly, the chromatographic peaks under TIC and EIC are automatically extracted, and then the analytical range of each TIC chromatographic peak is determined, and the EIC chromatographic peak information within the analytical range is searched. Clustering is performed according to the EIC chromatographic peak information, and a representative chromatographic profile spectrum of each class is obtained. After screening, the initial chromatogram matrix was constructed, and the modified multivariate curve resolution-alternating least squares method was used to optimize and analyze the initial chromatogram matrix to obtain the chemical composition under each TIC chromatographic peak. Import the mass spectrum of each chemical component obtained from the analysis into the mass spectral library to automatically match the compound, and complete the intelligent and accurate identification of the compound in the GC-MS of a single sample. The invention has good application value in the fields of scientific research, detection, industrial application and the like involved in GC-MS technology.

A compound-weight time-series data calculator creates a compound spectrum matrix based on standard mass spectra of various compounds stored in a standard mass spectrum library. Then, the calculator determines, in the form of a linear regression model, the relationship of the matrix, a measured vector based on the data acquired at one measurement time point, and a compound weight vector at the measurement time point, and estimates the unknown weight vector by a minimum norm estimation in which a regularizer is introduced. A compound-weight time-series graph creator creates a compound-weight time-series graph showing a temporal change in weight for each target compound, based on the compound weight vector obtained at the measurement time points within a specified time range. A peak which appears on this graph is used for the quantitative determination of the compound or determination on the presence or absence of the compound.

At least one product ion mass spectrum produced by a tandem mass spectrometer is received. A chemical structure of a compound that corresponds to the at least one product ion mass spectrum is received. One or more elemental compositions are assigned to at least one peak in the at least one product ion spectrum based on the chemical structure using the processor. At least one elemental composition of the one or more assigned elemental compositions is selected for the at least one peak using the processor. The mass of the at least one peak is converted to the mass of the selected at least one elemental composition using the processor, producing a product ion mass spectrum with higher mass accuracy.

The invention relates to the technical field of sulfonylurea herbicide detection, in particular to a method for on-line determination of sulfonylurea herbicides in water, which comprises the steps of sample collection, configuration of an on-line solid phase extraction system and configuration of a triple quadrupole composite linear ion trap mass spectrometer, and further comprises the following steps: adding information dependence acquisition and enhanced daughter ion scanning on the basis of multi-reaction monitoring, scanning a standard substance, and establishing a standard substance spectrum library by using an obtained enhanced daughter ion full-scanning mass spectrum; performing standard curve configuration on the standard solution; and carrying out on-line filtration and enrichment purification on the sample to obtain a purified substance, eluting and separating the purified substance, and finally detecting. The method has the advantages of simple operation, direct on-line sample analysis, short analysis time, less organic reagent dosage and high method sensitivity. In addition, the online solid-phase extraction and linear ion trap technology effectively reduces experimental errors caused by factors such as human interference and matrix interference, and the precision and accuracy of the method can be effectively improved.

The invention discloses a method for detecting 11 pigments in tobacco reconstituted tobacco. The method comprises the following steps of: 1) establishing high-resolution mass spectrum library information of 11 pigments by adopting double ternary high performance liquid chromatography and a high-resolution mass spectrum, the high-resolution mass spectrum database information comprising pigment names, retention time, [M+H]+ and [M-2H]2- ion accurate mass numbers, and characteristic fragment ion accurate mass numbers; and 2) performing pretreatment of to-be-detected tobacco reconstituted tobacco:extracting the to-be-detected tobacco reconstituted tobacco with a solvent to obtain to-be-detected liquid. The method has the advantages of the simple operation, the rapid detection and the high sensitivity, and can be applied to daily detection of reconstituted tobacco in cigarettes.

The invention discloses a detection method of volatile components of a xuefu zhuyu preparation and belongs to the field of column chromatography. The detection method adopts a headspace-gas chromatography-mass spectrometer to analyze volatile components in vessel stasis removing capsules and vessel stasis removing tablets. The detection method specifically comprises the following steps: (1) preparing test products; (2) optimizing analysis conditions of the volatile components of the vessel stasis removing preparation and performing sample detection; (3) analyzing data, searching an NISI-10 standard mass spectra library to obtain the volatile components in the vessel stasis removing capsules and tablets, and calculating the relative percentage content of each component. The detection method of the volatile components of the vessel stasis removing preparation fills a blank in the field of methods for detecting volatile substances in vessel stasis removing samples in the prior art, is simple, sensitive and quick, provides a basis for researches on the volatile components of the xuefu zhuyu preparation, and has a wide application value.

The invention relates to a liquid-mass database for detecting residual drugs in animal-derived foods and a method for using the database. The preparation of the database includes the following steps: (1) preparation of a standard working solution; (3) One-time sample injection chromatography analysis; (4) Construction of liquid mass spectrometry library.

The invention relates to a method for evaluating a flame retardant for inhibiting asphalt thermal cracking to generate volatile organic compounds, belongs to the technical field of asphalt material fire safety, and solves the problems that asphalt smoke is difficult to collect by adopting other volatile organic compound analysis methods, and other asphalt flame retardancy evaluation methods cannotspecifically evaluate the volatile organic compound inhibition effect of a flame retardant on asphalt pyrolysis. The method comprises the following steps: weighing asphalt and a flame-retardant modified asphalt sample, putting the weighed asphalt and flame-retardant modified asphalt sample into a tube furnace cracker for cracking, and setting the cracking temperature to be 550 DEG C, the crackerpressure to be 12psi and the cracking time to be 28s; setting programmed heating, starting from 40 DEG C, keeping the temperature for 5 minutes, heating to 270 DEG C at a speed of 5 DEG C / min, and keeping the temperature for 5 minutes; then, guiding pyrolysis fragments into an efficient capillary column to be separated, adopting carrier gas helium, setting the column head pressure to be 7 psi, andthe split ratio to be 25: 1; and finally, obtaining a cracking chromatogram of the thermal cracking volatile organic compound, and obtaining the name and kurtosis value of each substance through contrastive analysis of a mass spectrum library, so as to realize qualitative and quantitative contrastive analysis of the asphalt and the flame-retardant modified asphalt thermal cracking volatile organic compound.

The invention relates to a gas chromatography-mass spectrometry detection method for cuticle hydrocarbons of temperate bed bugs and tropical bed bugs, which belongs to the technical field of hydrocarbon detection and comprises the following steps: (1) sample preparation; (2) carrying out gas chromatography-mass spectrometry detection on the sample to be detected; and (3) detection and analysis: comparing the insect epidermis hydrocarbon mass spectrum obtained by analysis of the mass spectrometer with a standard mass spectrum provided by a standard mass spectrum library, and selecting a standard compound with a high matching degree as a preliminarily determined type or structure. The gas chromatography-mass spectrometry detection method for cuticle hydrocarbon of temperate bugs and tropical bugs has the characteristics of high specificity, simplicity and convenience in operation, high sensitivity, short sample analysis time and practicability.

A mass spectrum generation section (22) generates an original mass spectrum at a peak of a target compound based on data acquired through analysis on a sample. A background spectrum generation section (23) generates a background spectrum in accordance with each of a plurality of predetermined background acquisition conditions. A difference mass spectrum calculation section (25) obtains a difference mass spectrum by subtracting the each background spectrum from the original mass spectrum, and a spectrum similarity calculation section (27) calculates a similarity between each difference mass spectrum and a standard mass spectrum of a candidate compound selected from a spectrum library (28). A compound identification section (29) identifies the candidate compound as the target compound if the highest similarity exceeds a predetermined threshold.