406 results about "Gas chromatography mass spectrometer" patented technology

A method for detecting secondary metabolites in fresh tobacco leaves by using a derivatization GC-MS (Gas Chromatography-Mass Spectrometer) is characterized by comprising the steps: quickly collecting new tobacco leaves and quickly freezing the new tobacco leaves by using liquid nitrogen on the site, crushing the tobacco leaves after removing the moisture in the tobacco leaves by means of freeze drying, extracting the secondary metabolites from tobacco powder by using a solvent, drying the extracted liquid supernatant, then performing oximation reaction and silane derivatization on the dried extractive, and finally performing analysis by the GC-MS. The method has the prominent advantages that firstly, a method suitable for extracting the secondary metabolites in the fresh tobacco leaves is developed. As the area of the tobacco leaves is larger, the secondary metabolites are not uniformly distributed in the whole tobacco leaves, and the tobacco leaves are not applicable to the punching sampling technique. However, according to a tobacco leave collection and extraction method provided by the invention, the collection period and the metabolite composition of the tobacco leaves at the collected part can be truly reflected. Secondly, most of the important metabolites of the tobacco leaves such as saccharides, amino acids, organic acids, terpene alcohols in the fresh tobacco leaves can be simultaneously detected, and the method has the characteristics of high throughput detection.

The invention discloses a method for measuring sterol in tobaccos. The method comprises the following steps of: (1) deploying sterol standard templates containing internal standard with different concentrations, carrying out GC-MS (Gas Chromatography-Mass Spectrometer) analysis after derivatization, and plotting by utilizing the ratio of the sterol to internal standard peak area and the ratio of the sterol to internal standard concentration to obtain a standard curve; (2) carrying out acid hydrolysis, saponification and direct ultrasonic extraction on samples to be measured, and taking 1 muL for carrying out GC-MS analysis after derivatization; and (3) reading the ratio of the sterol to the internal standard concentration from the standard curve by utilizing the ratio of the sterol to theinternal standard peak area, and then calculating the amount of the sterol. The invention can be used for analyzing cholesterol, ergosterol, campesterol, stigmasterol and beta-sitosterol with a plurality of forms in tobacco leaves at the same time, has the advantages of accurate measurement and simple and convenient operation, and can be widely applied to tobacco industry.

The invention relates to the field of analytical chemistry and food safety, in particular to a detection method for residual quantity of multiple preservatives in cosmetics. According to a gas chromatography-mass-spectrography detection method which can detect the residual quantity of multiple preservatives in cosmetics simultaneously, sample extraction and purification are respectively processed according to differences of sample shapes and properties, and then a gas chromatography-mass spectrometer is adopted to carry out qualitative determination and quantitative assay. The detection method achieves simultaneous detection of 21 preservatives, and has the advantages of being simple and convenient, fast, sensitive, and the like. The detection minimum, the recovery rate and the degree of precision of the method all meet relevant demands for preservative detection in the cosmetics at home and abroad, so the method is suitable for detection and monitoring of the preservatives in the cosmetics.

The invention provides an analytical method for determining aromatic constituents in tea. The method adopts HS-SPME (headspace-solid phase microextraction), combines GC-MS (gas chromatography-mass spectrometer) with the Kovats retention index (KI), employs a 50/30mu m DVB/CAR/PDMS type SPME head, optimizes HS-SPME parameters, establishes an AMDIS (automated mass spectral deconvolution and identification system) combined with the KI, and establishes a tea aroma atlas database for analysis. Compared with the conventional tea aroma analysis, the provided analytical method is better in accuracy, efficiency, flexibility and comprehensiveness, and can be effectively applied to qualitative and quantitative analysis for identification of the aromatic constituents in the tea.

The invention belongs to the technical field of endogenous substance detection and discloses a GC-MS (gas chromatography-mass spectrometer)-based method for quantifying eleven types of short-chain fatty acids in intestinal contents and fecal samples. By adoption of a hydrochloric acid solution prepared from saturated salt water for acidification, high-stability ethyl acetate for extraction and N-tert-butyldimethylsilyl-N-methyl trifluoroacetamide MTBSTFA for derivatization, the eleven short-chain fatty acids in mouse intestinal contents and fecal samples are quantified by a gas chromatography-mass spectrometer. The method is high in accuracy and precision and low in detection limit, can be used for quantitative detection of eleven types of short-chain fatty acids and can meet detection requirements on determination of major short-chain fatty acids in the mouse intestinal contents and the fecal samples. Moreover, the method is conducive to analysis and comparison of metabolic disposition laws of the short-chain fatty acids under normal and enteritis conditions and observation whether changes of the short-chain fatty acids can represent dynamic conditions of enteritis or not, thereby providing significant bases for potential biomarkers under the enteritis condition.

The invention provides a method for detecting primary metabolites and secondary metabolites in fresh tobacco leaves with GC-MS (gas chromatography-mass spectrometer). The method comprises steps as follows: the fresh tobacco leaves are rapidly collected and quick-frozen with liquid nitrogen on site, the quick-frozen tobacco leaves are transferred to dry ice and transported to a laboratory at low temperature, moisture is removed by a freeze dryer with a low-temperature freeze drying method, the tobacco leaves are pulverized by a pulverizer and screened by a 40-mesh sieve, the primary metabolites and the secondary metabolites of the pulverized tobacco leaves are extracted ultrasonically with a solvent, a supernatant of an extracting solution is subjected to nitrogen blow-drying, blow-dried extracts are subjected to an oximation reaction and a silane derivatization reaction, and GC-MS analysis is performed finally. The method has the advantages as follows: a tobacco leaf collecting method can really reflect growth and development periods, collecting parts, varieties and production places of the tobacco leaves; a tobacco leaf extracting and detecting method can cover the primary and secondary metabolites such as sugar, amino acid, organic acid, sterol, alkaloid, polyphenol and the like of the fresh tobacco leaves and has high-flux detection characteristics, and a selective ion monitoring method can realize accurately qualitative and quantitative analysis of 199 primary and secondary metabolites in the fresh tobacco leaves, and 135 metabolites are required to be verified in a standard substance.

The invention discloses a method for detecting the content of a triocresyl phosphate fire retardant of a rubber part of an electrical or electronic product. The method comprises the following steps of: (1) sample preparation; (2) extraction of the triocresyl phosphate fire retardant: adding heavy metal powder into the sample, uniformly mixing and performing accelerated solvent extraction so as to obtain extract; (3) extract purification: uniformly mixing the extract and an interior label, transferring to a small solid phase extraction column, eluting by using a mixed solvent, collecting and concentrating eluent so as to obtain the purified extract; and (4) measurment of the triocresyl phosphate fire retardant: measuring the purified extract and the triocresyl phosphate mixed standard solution containing the interior label by using a gas chromatography-mass spectrometer, and performing data processing and quantitative analysis to obtain the content of the triocresyl phosphate fire retardant. By the method, interference impurities in the rubber can be eliminated effectively, triocresyl phosphate can be extracted fully, the purification degree is high, the detection sensitivity is high and the sample measurement cost is low.

The invention discloses a detection method and a device for volatile and semi-volatile components. The detection method for the volatile and semi-volatile components comprises the steps of collecting, preparing and analyzing samples and especially comprises the following steps of: performing catching by a filter disc, adding an organic solvent, and performing ultrasonic oscillation to obtain the sample; and performing liquid chromatographic separation on the sample, cutting flow-out components into a catching coil pipe, conveying the sample in the catching coil pipe into a gas chromatography (GC) device, adsorbing the sample by a solid phase extraction column, starting a gas chromatography-mass spectrometer (GC-MS), and analyzing components to be measured in a capillary separation column. The device is a liquid and gas phase bi-dimensional chromatography device, and solvent treatment between the liquid chromatography (LC) device and the gas chromatography device is solid phase extraction. According to the method and the device, the sample can enter a first-level LC with a large size, and fractions of the first-level LC can be cut into a second-level GC with a large size, so that as for the low-content samples, components separated by LC can be accumulated for many times, and then are transferred into the GC for analysis after being accumulated to an ideal analysis amount. Therefore, the samples can be efficiently purified, and the analysis sensitivity is greatly improved.

The invention relates to a method for measuring volatile fragrance components of an electronic cigarette. The method comprises the steps of adding electronic cigarette liquid into a headspace sample injection bottle, adding a solvent into the headspace sample injection bottle for uniform mixing, and sealing a bottleneck of the headspace sample injection bottle through a bottle cover; performing aging treatment on a solid-phase microextraction needle fiber head at a gas chromatography sample injection opening; performing headspace solid-phase microextratcion on the electronic cigarette liquid; performing desorption on substances obtained by extraction at the gas chromatography sample injection opening; qualitatively and quantitatively analyzing the desorbed substances through a gas chromatography-mass spectrometer. According to the method, the loss or the decomposition of the volatile fragrance components of the electronic cigarette can be effectively avoided; multiple volatile fragrance components can be simultaneously analyzed; the method is high in repetitiveness, high in sensitivity and easy to operate; the interference caused by base body components and the solvent can be avoided; the method has a certain advantage in detecting the volatile fragrance components.

The invention belongs to the technical field of physiochemical detection of tea leaves and in particular relates to a method for determining alkaloids in tea leaves by using a GC-MS (Gas Chromatography-Mass Spectrometer) method. The method comprises the following step of determining nicotine and minor alkaloids (including nicotine, nornicotine, myosmine, neonicotine, neonicotine and cotinine) in tea leaf powder. The method is a method for extracting nicotine substances from the tea leaves by using a centrifugal tube filled with 0.01% triethylamine/tert-butyl methyl ether solution and analyzing the nicotine substances in the tea leaves by using a gas chromatography-mass spectrometer (GC-MS) method. When the method provided by the invention is used for detecting the content of the nicotine in the tea leaves, the method is rapid and effective, the pre-treatment is simple, an average relative standard deviation is smaller than 10 percent, and the average recycling rate of each index is 86.2 percent to 92.1 percent. The method has the advantages of rapidness and accuracy, high sensitivity and good repeatability.

The invention discloses a total-detection method of volatile N-nitrosamine compounds in foods. The total-detection method comprises the steps: sample extraction, qualitative analysis, quantitative determination, result analysis, and result conversion, wherein the sample extraction comprises distilling, extracting, concentrating and performing constant volume operation; the qualitative analysis is performed by adopting a gas chromatography-mass spectrometer; the quantitative determination is performed by adopting a gas chromatography. According to the total-detection method, the N-nitrosamine compounds in the foods are totally detected by adopting an NO and N2O dual-probe ion technology, and thus the species of the N-nitrosamine compounds can be accurately screened, non-N-nitrosamine compounds can be effectively eliminated, the false detection and the leak detection are prevented; nitrosamine compounds can be once distinguished from multiple volatile organic compounds, limited and less relevant nitrosamine compounds can be directly qualified and quantified, and thus the analysis time is greatly saved.

The invention discloses a method for measuring dimethyl fumarate in a product by gas chromatography-mass spectrometry. The method comprises the following steps of: pretreating a dimethyl fumarate product to be detected by using an ultrasonic extraction method; setting the temperature of a sample injection port of a gas chromatography-mass spectrometer to be 240-280 DEG C, a flow rate to be 0.8-1.5 ml/min and the temperature of a port to be 280-300 DEG C, and selecting a weak polar column for a chromatographic column; enabling a sample to enter the chromatographic column through the sample injection port, and carrying out temperature programming on the temperature of the chromatographic column to separate the components of the sample by the chromatographic column; and enabling the components separated by the chromatographic column to enter a mass spectrometric detection part through the port of the gas chromatography-mass spectrometer, wherein an electron impact ion source is adopted as the ion source of the mass spectrometric detection. The method for measuring the dimethyl fumarate in the product by the gas chromatography-mass spectrometry has low detection limit, good detection effect, little consumption of analysis solvent and low detection cost.

The invention discloses a method for degrading triphenyl phosphate through brevibacillus brevis and application thereof and belongs to the technical field of environment organic pollutant biotreatment. The method specifically comprises the steps that a degradation culture medium with triphenyl phosphate as a unique carbon source is inoculated with the brevibacillus brevis under the condition that the temperature is 30 DEG C; five days after degradation of a constant-temperature shaking table, the concentration of the triphenyl phosphate left in the culture medium is measured through a gas chromatography-mass spectrometer (GC-MS), and in this way, the degrading effect of the brevibacillus brevis on the triphenyl phosphate is analyzed. According to the method, environment suitability of the method is high, and the cost is low; the degradation rate of organophosphorus fire retardant can reach 95.4% five days later. The actual application value is high, and a reference is provided for solving the problem of water organophosphorus fire retardant pollution treatment.

The invention provides a gas chromatography-mass spectrometry detection method of three very long chain fatty acids in a human serum. The method comprises the following steps (1) carrying out pretreatment on a human serum sample to obtain a derivative product; (2) detecting the derivative product by using a gas chromatography-mass spectrometer; (3) carrying out qualitative analysis on each very long chain fatty acid in the human serum sample according to a total ion chromatogram and a mass spectrogram of the derivative product, and calculating the content of each very long chain fatty acid in the human serum sample according to a selective ion chromatogram, wherein each very long chain fatty acid comprises docosanoic acid, tetracosanoic acid and hexacosanoic acid. Compared with the background art, the pretreatment process disclosed by the invention is fast, sensitive and accurate.

The invention discloses a method for quickly and accurately evaluating the quality stability of a cigarette product. The method comprises the steps of collecting GC-MS chromatograms of more than 10 batches of cigarette products which have the same brand specification as that of the cigarette product to be detected and are purchased in the proper way by a purge trap-gas chromatography-mass spectrometer combination method, and averagely acquiring a chromatograph fingerprint of the cigarette of the brand specification by stacking; collecting the GC-MS chromatograms of a batch of cigarette samples to be detected, and analyzing the similarity between the GC-MS chromatograms of a batch of cigarette samples to be detected and the chromatograph fingerprint of the cigarette of the brand specification by a relevant coefficient method, and judging the cigarette products with the similarity being greater than or equal to 90 percent to be cigarette products with stable quality and the cigarette products with the similarity being smaller than 90 percent to be cigarette products with unstable quality. The method has the advantages of simplicity in operation treatment, high spectrum specificity, quickness and accuracy in conclusion making, and the like.

The invention relates to a low-temperature pressurization head space sample injection device for measuring volatile substances in the atmosphere through a GC-MS (gas chromatography-mass spectrometer) technology. The low-temperature pressurization head space sample injection device comprises a reciprocating full-glass piston pump which consists of a glass piston cylinder barrel (1), a unidirectional valve a (2), a unidirectional valve b (3), a clamp (4), a crank-link mechanism (5), a micro motor (6) and a worm speed reducer (7), a sampling head space bottle which comprises a head space bottle body (10) and cooling equipment, wherein a seal is arranged at the head space bottle; two injection needle heads with different lengths are inserted into the seal; the long needle head is in contact with the bottom to serve as a gas inlet needle (8); the short needle head is positioned at a bottleneck to serve as a gas exhaust needle (9); the gas inlet needle (8) is connected with the unidirectional valve b (3); the gas exhaust needle (9) is connected to a GC-MS; the head space bottle body (10) is arranged in the cooling equipment (12). Compared with the prior art, the low-temperature pressurization head space sample injection device has the advantages that the efficiency of collecting the volatile components in the atmosphere can be improved, so that the volatile components in the atmosphere can be fully collected and can be subjected to quantitative and qualitative compound analysis in the GC-MS.

The invention provides a method for simultaneously determining PAHs (polycyclic aromatic hydrocarbons) and n-alkanes in atmosphere particulates. The method comprises the following steps of collectingof a sample, purifying of the sample, and determining of the sample; GC-MS (gas chromatography-mass spectrometer) is used for determining, and a chromatographic column is a capillary chromatographic column with weak polarity, the MS adopts an EI (electromagnetic interference) source and MRM (multi-reaction mode) mode, the electron energy is 70eV, and the temperature of an ion source is 230 DEG C;in the heating procedure during PAHs determination, the initial column temperature is maintained at 40 DEG C for 2min, and is heated to 100 DEG C at the rate of 10 DEG C/min, the temperature of 100 DEG C is maintained for 1min, then the temperature is heated to 250 DEG C at the rate of 20 DEG C/min, and the temperature of 250 DEG C is maintained for 3min; in the heating procedure during n-alkanesdetermination, the initial column temperature is maintained at 50 DEG C for 2min, and is heated to 300 DEG C at the rate of 5 DEG C/min, and the temperature of 300 DEG C is maintained for 20min.

The invention discloses a construction method for a GC-MS (Gas Chromatography-Mass Spectrometer) fingerprint of edible oil, and belongs to the field of edible oil detection and analysis. The construction method comprises the steps of (1) pretreating a sample; (2) collecting a GC-MS fingerprint of edible oil; and (3) constructing the GC-MS fingerprint of edible oil. The GC-MS fingerprint is applied to qualitative detection and adulteration detection of edible oil. Common peaks of the fingerprint are respectively calibrated by constructing the fingerprint of common edible oil; by virtue of quantitative and qualitative analysis on the common peaks, all oil samples to be detected can be distinguished and identified; adulterated edible oil can be analyzed and identified according to the GC-MS fingerprint; the construction method is used conveniently and quickly and is high in authentication accuracy. The GC-MS fingerprint has an extremely high application value in the aspects of daily edible oil quality analysis, market supervision, detection of industrial production and the like.

The invention provides a detection method for simultaneously measuring residual toluene 2,4-diisocyanate (2,4-TDI), toluene 2,6-diisocyanate (2,6-TDI) and diphenylmethane diisocyanate (MDI) in the product by using precolumn derivatization-gas chromatography-mass spectrography. The method comprises the following specific steps: performing ultrasonic extraction on a sample, performing rotary evaporation and concentration on the extracting solution, reacting in an acidic aqueous solution, neutralizing with an alkali liquor, extracting by using an organic solvent, performing organic phase derivatization, removing excessive derivatization reagents with a buffer solution, taking the organic phase as a to-be-measured solution after solution separation, measuring and confirming by using a gas chromatography-mass spectrometer, carrying out a blank experiment, quantifying by using an external standard method, measuring the target compound in the sample solution, and the like. According to the method, the measurement parameters and test steps of the gas chromatography-mass spectrography are reasonably selected, the content of 2,4-TDI, 2,6-TDI and MDI in leather, artificial leather and textiles can be simultaneously measured by adopting selective ion scanning detection and external standard method quantification, and the results are simultaneously obtained by virtue of one-step pretreatment. The method has the characteristics of high precision, high interference resistance and low detection limit.

The invention discloses an atmospheric organic aerosol detection and source analysis method. By virtue of offline collection of atmospheric aerosol samples, the spatial resolution of the atmospheric aerosol samples and the size range of particles measured by an aerosol mass spectrometer (AMS) can be widened, and long-term observation of the aerosol can be realized. By virtue of water-soluble and water-insoluble extracted samples, the total components of the organic aerosol can be maximally reduced. The method comprises the following steps: respectively measuring water-soluble organic samples and water-insoluble organic samples by using the AMS, and measuring to obtain an initial water-soluble organic mass spectrum matrix and an initial water-insoluble organic mass spectrum matrix; analyzing the water-soluble organic samples by using a TOC (Total Organic Carbon) analyzer, analyzing the water-insoluble organic samples by using an OC/EC (Organic Carbon/Elemental Carbon) analyzer, and correcting the data acquired by the AMS; performing PMF analysis to obtain factors, and performing correlation comparison with molecular markers measured by the GC-MS (Gas Chromatography-Mass Spectrometer) and LC-MS (Liquid Chromatograph-Mass Spectrometer), thereby improving the source analysis result accuracy. In addition, the filter membrane collection and sample analysis method is simple in operation, and the manpower and equipment maintenance cost is greatly saved.

A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from a fixed surface so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agent, chemical attribution signatures and toxic industrial chemicals.

The invention discloses a quick detection method for 58 types of allergenic fragrance in children products. The quick detection method comprises the following steps: carrying out preliminary treatment on a sample, smashing the sample, evenly mixing, putting a proper quantity of samples into a 44-bit automatic headspace sampler, or extracting by solvent, putting the extracted solution into the 44-bit automatic headspace sampler, setting a headspace condition, volatilizing and transferring the allergenic fragrance to a gaseous phase, and introducing gas into a gas chromatography-mass spectrometer to realize detection, wherein the sample comprises velvet fabric, wooden and plastic samples. The quick detection method for 58 types of allergenic fragrance in children products has good linearity and high selectivity, sensitivity, accuracy and precision.