37 results about "Selected ion monitoring" patented technology

The invention provides a method for determining multiple kinds of animal origin meat based on the liquid chromatographic-tandem mass spectrometric technology. The method includes the steps of pretreating samples, screening multiple standard meat sample feature polypeptides, and detecting feature polypeptides in meat samples to be detected through the liquid chromatographic-tandem mass spectrometric technology and the like. Components of the multiple kinds of animal origin meat can be identified by adopting the method, the scanning function of liquid chromatography-tandem mass spectrometry is brought into full play in the technology, the selected ion monitoring mode is monitored to collect signals in real time, second-level daughter ion intensity triggering is used, corresponding parent ion second-level fragmentation full-scanning spectrograms are collected to obtain a more exact qualitative information function, interference of a complex matrix is avoided, and the false positive possibility is reduced. In addition, the method is simple in pretreatment and facilitates operation on samples in batches.

In a chromatograph mass spectrometer capable of defining an appropriate measurement time range and selectively performing a scan measurement, selected ion monitoring (SIM) measurement or simultaneous scan/SIM measurement in that time range, a total ion chromatogram 51 obtained by a scan measurement of a standard sample and a previously-created compound table 52 are displayed on the screen of a display unit in the process of setting parameters in a measurement condition table. An operator selects a compound that should undergo the simultaneous scan/SIM measurement, then places a checkmark in an appropriate check box in the compound table 52, and finally clicks the “Auto-Create” button 54. Then, a measurement time range for the selected compound is defined by adding a time span before and after the retention time of that compound, respectively, and a measurement condition table 53 is automatically created and displayed on the screen. This table includes instructions for performing a simultaneous scan/SIM measurement at specific mass-to-charge ratios characteristic of the selected compound during the aforementioned measurement time range.

The invention discloses a method for detection of electronegative element containing pesticides by a negative chemical ionization mass spectrum database. The method includes the steps of: establishment of the negative chemical ionization mass spectrum database and detection of pesticide residue in unknown sample. And establishment of the negative chemical ionization mass spectrum database consists of mass spectrum acquisition and mass spectral library establishment. The database involved in the invention includes full scan mass spectrum data of over 300 common electronegative element containing pesticides in a Thermofisher gas chromatography negative chemical ionization mass spectrum, after installation and operation on a Thermofisher gas chromatograph-mass spectrometer, spectrum library search comparison with an unknown sample can be carried out, or according to the ion information provided by the spectrum library, a selected ion monitoring (SIM) scan mode can be set directly to perform qualitative and quantitative detection on designated pesticides. The negative chemical ionization mass spectrum database is convenient to use, the impurity interference is small, the selectivity is high and the comparison result is accurate.

The invention relates to a method for selectively determining residual vinyl acetate in white latex for cigarette through static headspace and gas chromatography mass spectrometry, belonging to the technical field of physical and chemical inspection of materials for the cigarette, and provides a quantitative selected ion determining method through the static headspace and gas chromatography mass spectrometry, aiming at selectively determining the residual vinyl acetate in white latex for the cigarette. A sample of the white latex for the cigarette after static headspace at 80 DEG C for 15 minutes is detected by taking 2-hexanone as an internal standard through HP-INNOWAX column in a GC-MS/SIM (Gas Chromatography Mass Spectrometry/Selected Ion Monitoring) mode, and is quantified through an internal standard method. According to the method for selectively determining the residual vinyl acetate in the white latex for the cigarette through the static headspace gas chromatography mass spectrometry, disclosed by the invention, detection limit, labeling recovery ratio and RSD (Relative Standard Deviation) of the method are respectively 0.63mg/kg, 104-107% and 2.5-4.9%; in addition, the method disclosed by the invention has the characteristics of simpleness, fastness, accuracy, sensitiveness and the like, and is especially suitable for quantitative analysis on the residual vinyl acetate in the white latex for the cigarette.

The invention discloses a chemical profile analysis method based on a retention time locking-gas chromatography-quadrupole mass spectrometry-selected ion monitoring mode. Firstly, the method employs a gas chromatography-mass spectrometry (GC-MS, full scan mode) method to analyze quality control samples, performs mass spectral de-convolution and peak identification on obtained full scan information with an automated mass spectral deconvolution and identification system (AMDIS), extracts chromatographic retention time information corresponding to identified compounds from AMDIS result documents, and groups chromatographic peaks at different retention time according to the information. Then, the method extracts mass spectral information from an original data file, selects characteristic ions, establishes a retention time locking GC-MS method, and performs selected ion monitoring on all the to-be-analyzed samples. Reliability, efficiency and maneuverability of chemical profile analysis data obtained by employing the gas chromatography-mass spectrometry are improved. The method also can be extended to chemical profile analysis based on liquid chromatography-mass spectrometry.

The invention discloses a universal total-component quantitative analysis method of gas chromatography-mass spectrometry. Firstly, the method employs a gas chromatography-mass spectrometry (GC-MS, full scan mode) method to obtain data information of to-be-analyzed samples, performs mass spectral de-convolution and peak identification on obtained full-scan information with an automated mass spectral deconvolution and identification system (AMDIS), extracts mass spectral information from an original data file according to results of peak identification, calculates characteristic values of compound ions, chooses characteristic ions of the compound, and finally establishes selected ion monitoring quantitative analysis method with the characteristic ions. A core of the method lies in choosing characteristic ions of the compound through the characteristic values of the compound ions. The method can give a plurality of characteristic ions and characteristic values to characteristic evaluation indexes thereof. The given characteristic ions can be used as quantitative ions and quantitative candidate ions.

The invention relates to a gas chromatography-mass spectrometry rapid determination method for non-registered components in a pesticide preparation, and belongs to the technical field of pesticide quality detection. The gas chromatography-mass spectrometry rapid determination method for the non-registered components in the pesticide preparation comprises the following steps of preparing a standardsolution; preparing a sample solution; preparing a blank solution; performing GC-MS detection: injecting the standard working solution and the blank solution into a GC-MS, performing selected ion monitoring, and performing regression analysis on the corresponding concentrations of the non-registered components by the quantitative ion peak areas of the non-registered components after blank deduction, so as to obtain a standard working curve; and injecting a to-be-detected sample solution into the GC-MS under the same condition, obtaining the quantitative ion peak areas of the non-registered components in the sample after blank deduction, and substituting the quantitative ion peak areas into the standard working curve, so as to obtain the content of the non-registered components in the sample. According to the method disclosed by the invention, the capability of performing high-throughput accurate qualitative screening and accurate quantitative detection on the 131 non-registered components in the pesticide preparation is realized, so that the detection types and the detection efficiency are greatly improved.

The invention relates to a determination method for 18 polycyclic aromatic hydrocarbons (PAHs) in tire filling oil. The method is characterized by including the following specific detection steps: preparation of a mixed standard solution and an internal standard substance mixed stand solution, sample preparation, solid phase extraction, GC-MS test: taking of an extracted liquid C for gas chromatography-mass spectrometry qualitative and quantitative analysis, drawing of a standard work curve, and result calculation. The method provided by the invention uses solid phase extraction for sample purification, employs internal standard method for quantitative analysis, and uses a selected ion monitoring mode of GC-MS for detection and analysis, the method needs short time for extraction, can achieve a highest extraction recovery rate, also avoids the matrix interference, and has the advantages of simplicity and practicability, high purification efficiency and short extraction time.

The invention discloses a laboratory quality control technology for phthalate detection in wine and application thereof. The detection technology is as follows: extracting phthalate in a sample with n-hexane, taking a supernatant for dehydration, using d4-di (2-ethyl) hexyl phthalate (d4-DEHP) as an internal standard for detecting by gas chromatography-mass spectrometry. By using feature selected ion monitoring scan mode (SIM), chromatographic retention time and debris abundance ratio are taken for determination on the nature and an internal standard method is taken for determination on the quantify. The method provided by the invention is simple, good in stability, high in sensitivity and convenient to use, and can realize the rapid on-site detection of the phthalate.

The invention discloses a method for determining ethyl 2-aminobenzoate grape essences in wine with gas chromatography-mass spectrography. A wine sample is subjected to extraction with n-hexane servingas an extractant, a selected ion monitoring mode of a gas chromatography-mass spectrometer is used for determination after specific liquid-liquid extraction purification treatment is performed, and quantitation is performed with an external standard method. Results show that the three ethyl 2-aminobenzoate grape essences in the wine show a good linear relation in the range of 0.05-1.00 mg/L, correlation coefficient r values are all larger than 0.999, the quantitation limit of the method is 5 mu g/L, the average recovery rate of the sample is 86.2%-102.4%, and the average relative standard deviation is 1.02%-8.75% (n is 6). The method is convenient, quick, accurate and sensitive, has good recovery rate and stability and is applicable to quick determination of ethyl 2-aminobenzoate grape essences in the wine.

The invention discloses a rapid detection method for three common anesthetics in aquatic products, and belongs to the technical field of detection. According to the method, a single quadrupole gas chromatograph-mass spectrometer (GC-MS) is used for screening, quantification and confirmation, a Thermo TG 1701 MS capillary column is used as an analytical column, and the method for determining the content of three anesthetics, namely eugenol (Eugenol, CAS: 97-53-0), isoeugenol (Isoeugenol, CAS: 97-57-1) and 3-aminobenzoic acid ethyl ester methyl sulfonate (MS-222, CAS: 886-86-2), in the aquatic product is established in a positive ion selected ion monitoring mode (SIM). According to the method, the detection limit of eugenol and isoeugenol is 25.0 [mu] g/kg, and the detection limit of 3-aminobenzoic acid ethyl ester methyl sulfonate is 50.0 [mu] g/kg. Compared with a traditional instrument analysis method, the detection method is simpler and quicker, has higher linear correlation, and has the characteristics of high sensitivity, matrix interference resistance, high accuracy and high stability.

Disclosed are methods for improving compound detection and characterization. Methods for characterizing a sample are disclosed. The methods can include providing a sample to a liquid chromatography system capable of sample separation to generate sample components; analyzing sample components by multiplexed targeted selected ion monitoring (SIM) to generate an inclusion list; and performing iterative mass spectral data-dependent acquisition (DDA) from the inclusion list, to identify individual sample components thereby characterizing the sample. In one example, multiplexed targeted SIMs and iterative MS2 DDA acquisition is used to increase robust compound identification for cell culture medium analysis.

A technician is forced to determine the measurement time to be used in a selected ion monitoring (SIM) measurement while observing mass spectral data. Thus, mass spectral data and one or a plurality of mass chromatogram data items is generated on the basis of the detection results of an ion detection unit, and, for each corresponding ion component, the measurement time to be used in SIM is determined on the basis of the elution time range represented by each peak waveform of the one or plurality of mass chromatogram data items that have been generated.

The invention discloses a method for measuring content of vanillin and ethyl vanillin in an additive for cigarettes. The method is used for analyzing vanillin and ethyl vanillin in the additive for cigarettes by using a gas chromatograph-selected ion monitoring mass spectrometer (GC/MS) taking naphthalene as an internal standard, and comprises steps of interior label solution preparation, sample treatment, standard working solution preparation and sample measurement, and has the characteristics of rapid measurement, simplicity and convenience in operation, high recycling rate, good repeatability and the like. By adopting the method, the vanillin recycling rate is 96.7-99.2%, the recycling rate of the ethyl vanillin is 97.5-103.0%, and the RSD of the vanillin is 3.86-4.86%, and the RSD of the ethyl vanillin is 1.89-2.98%.

The invention belongs to the technical field of aquaculture and food monitoring, discloses a method for determining geosmin and dimethylisoborneol in a fish body based on a rapid pretreatment technology, and establishes a detection method for determining GSM and 2MIB in fish tissues through dispersive solid phase extraction-gas chromatography-mass spectrometry. The method comprises the following steps: extracting a sample with an acetonitrile solution, and performing salting-out assisted extraction; after purification, under a gradient heating condition, subjecting a target analyte to qualitative analysis by comparing retention time and ion pair information in a selected ion monitoring mode, and performing quantification by an internal standard method. The method has the advantages of small required sample amount and reagent amount, high analysis speed, high sensitivity and good reproducibility. The method can meet the large-batch detection requirements of GSM and 2MIB in fish tissue samples, and provides a rapid detection technical guarantee for evaluating the occurrence condition of earthy smell substances in fish tissues and exploring the reduction and removal of typical earthy smell substances in fish bodies.

The invention relates to a high-performance liquid chromatography-mass spectrometry method for simultaneous and rapid determination of flavonoids and lactones in ginkgo extract and its preparation. The method comprises the following steps: diluting the sample with 50% methanol/50% water; utilizing RP-HPLC method to carry out the determination of flavonoids and lactones, and establishing the HPLC-MS simultaneous determination method of 16 kinds of flavonoids and 4 kinds of lactones in the ginkgo extract preparation , the mobile phase selected in the determination process was composed of acetonitrile and water, the flow rate was 0.3mL/min, the column temperature was 35°C, the injection volume was 5μL, and the mass spectrometry selected ion monitoring (MRM) mode was used for detection; 16 kinds of flavonoids and 4 kinds of lactones were used as The standard sample was used to establish the linear equation of the HPLC-MS determination method. The method is fast, simple, accurate and reliable, and stable, and is suitable for the simultaneous qualitative and quantitative analysis of flavonoids and lactones in Ginkgo biloba extract and its preparations.