930 results about "Internal standard" patented technology

The invention provides a bloodstain leaving time detection method, and belongs to the technical field of forensic medicine detection. The method comprises the following steps: sampling a carrier attached with bloodstains to obtain a first sample, and sampling a carrier not attached with bloodstains to obtain a second sample; preparing an internal standard solution with a set concentration, and respectively filling the internal standard solutions with the same volume into different headspace bottles; respectively combining the first sample and the second sample with a headspace bottle, and respectively putting into a headspace solid-phase extractor for extraction treatment; analyzing by using a gas chromatograph-mass spectrometer to obtain a volatile organic compound (VOC) map, and determining actually measured VOC components according to the VOC map corresponding to the first sample and the VOC map corresponding to the second sample; and determining the bloodstain leaving time according to the actually measured VOC components and the bloodstain leaving time analysis model. According to the method, the influence of object factors on the bloodstain leaving time inference result can be reduced, and the accuracy and efficiency of the bloodstain leaving time inference result are improved.

The invention discloses a model method for predicting cheese preference degree based on GC-MS combined with machine learning, and belongs to the technical field of cheese evaluation. The method comprises the following steps: firstly, determining the cheese preference of Chinese consumers by adopting a method for checking all suitable items, determining the nature of volatile flavor compounds by combining headspace-arrow type solid-phase microextraction and gas chromatography-mass spectrometry, and quantifying by adopting an internal standard curve method. Secondly, the correlation between the sensory attributes and the compounds is established through quantitative description analysis and Pearson correlation coefficients, and the characteristic flavor compound of each sensory attribute is obtained; and finally, establishing a cheese consumer preference degree identification method by using a machine learning algorithm, and predicting the Chinese consumer preference degree of unknown cheese by using the model. According to the method, the cheese preference degree of Chinese consumers can be accurately recognized only by means of data obtained through instrument analysis and the classification model, a set of more objective and rapid cheese consumer preference degree prediction method is established, and more accurate prediction is achieved along with the increase of sample libraries.

The invention discloses a single-cell metabolite spectrum quantitative analysis platform and method based on droplet microfluidics, and relates to the technical field of mass spectrometry. The platform comprises a fluid pumping module, a cell oscillation module, a microfluidic mixed liquid drop generation module, a microfluidic mixed liquid drop reinjection and separation module and a mass spectrometry module. The fluid pumping module comprises a high-pressure nitrogen cylinder and a gas pressure driver; the cell oscillation module comprises a cell oscillator; the micro-fluidic mixed droplet generation module comprises a micro-fluidic droplet generation chip, a cell lysis solution, an internal standard, an oil phase, a cell suspension and a droplet collection and incubation centrifugal tube; the micro-fluidic mixed liquid drop reinjection and separation module comprises a micro-fluidic liquid drop reinjection and separation chip; and the mass spectrometry module comprises an electrospray needle and a mass spectrometer. According to the method, the single cell is captured and the internal standard substance is introduced at the same time by using droplet microfluidics, and mass spectrometry is carried out, so that high-flux single cell encapsulation and accurate quantification of metabolites are realized.

The invention belongs to the technical field of analysis and detection, and discloses a method for detecting perfluorinated and polyfluoroalkyl substances in cosmetics, which comprises the following steps: (1) mixing a perfluorinated and polyfluoroalkyl substance standard solution and an isotope internal standard solution to obtain a mixed standard solution; detecting the mixed standard solution by adopting a liquid chromatograph-mass spectrometer, drawing a standard curve, and calculating to obtain a linear equation; (2) mixing a cosmetic sample with the isotope internal standard solution, adding an extracting solution, extracting, and filtering to obtain a mixed solution to be detected; detecting the mixed to-be-detected solution by adopting the liquid chromatograph-mass spectrometer to obtain a detection result, and substituting the detection result into the linear equation to obtain the content of the perfluoro and polyfluoroalkyl substances in the mixed to-be-detected solution, the perfluoro and polyfluoroalkyl substances comprise perfluorocarboxylic acid, perfluorosulfonic acid, a fluorine polymer, perfluoroalkyl ether sulfonic acid, saturated fluorine telomere acid and perfluoroether carboxylic acid.

The invention discloses a method for rapidly and accurately determining the content of organochlorine pesticides in water, and belongs to the field of organochlorine pesticide content determination, and the method comprises the following steps: adding a regulator into a water sample, uniformly shaking, adding a substitute, and uniformly shaking again; adding sodium chloride into the water sample treated in the step S1, putting the water sample into a liquid-liquid extraction oscillator, and oscillating until the water sample is completely dissolved; s2, adding an extracting agent into the water sample treated in the step S2, vigorously oscillating, standing for layering, putting the lower-layer water sample into a reagent bottle, transferring an upper-layer extracting solution into a drying column, washing and dehydrating, and then transferring into a concentration bottle; the step S3 is executed again on the remaining water sample in the step S3; and S4, combining the eluents in the steps S3 and S4, transferring into a full-automatic nitrogen blowing instrument, concentrating to 1ml, adding an internal standard solution, and performing gas chromatography-mass spectrometer analysis after volume metering to obtain the content of the organochlorine pesticide in the water sample. The method has the beneficial effects that the method has the advantages of high efficiency, rapidness and accurate detection, and the method is simple to operate, low in cost and high in concentration efficiency and recovery stability.

The invention discloses a method for detecting the contents of VMA, HVA and 5-HIAA in urine by using liquid chromatography-tandem mass spectrometry. The method comprises the following steps: S1, removing VMA, HVA and 5-HIAA in urine to obtain a blank urine matrix; s2, weighing VMA, HVA and 5-HIAA solid powder, fixing the volume with methanol, mixing the dissolved liquids, diluting with methanol-water to obtain a VMA, HVA and 5-HIAA working solution, and finally diluting step by step with a blank urine matrix to obtain a calibration product; s3, respectively taking a urine sample to be detected, the calibration substance and the quality control substance, adding the mixed internal standard working solution of VMA, HVA and 5-HIAA isotopes, uniformly mixing, centrifuging, and taking supernate; s4, separating the supernate by using liquid chromatography; s5, the separated supernate enters a mass spectrum to be detected, and the content of VMA, HVA and 5-HIAA in the urine sample to be detected is obtained. The detection method disclosed by the invention is simple and rapid in pretreatment, high in specificity, low in reagent consumption cost, free of environmental pollution, small in required sample size, easy in high-throughput operation and suitable for being developed into a kit for conventional clinical detection.

The invention provides a method for simultaneously detecting perfluorinated compounds in mouse tissues and organs, and belongs to the technical field of analysis and detection. The method provided by the invention comprises the following steps: mixing a mouse visceral organ tissue sample, an alkaline buffer solution and an internal standard solution, and homogenizing to obtain homogenate; mixing the homogenate with tetrabutylammonium hydrogen sulfate and methyl tert-butyl ether, and carrying out liquid-liquid extraction to obtain extract liquor; and sequentially drying and redissolving the extract liquor, and carrying out ultra-high performance liquid chromatography-tandem mass spectrometry analysis to obtain a result of the perfluorinated compound in the mouse tissue visceral organs. The result of the embodiment shows that the adding standard recovery rate of 14 target objects in the method provided by the invention is 64.9%-120.3%, the RSD of 6 repeated tests is 1.0%-14.0%, the matrix effect of the target objects is 83.7%-134.0%, and the matrix effect is relatively low; and the detection result has excellent accuracy and reproducibility.

The invention discloses an LC-MS / MS detection method for a palbozuril monoclonal antibody drug in a blood sample, which comprises the following steps: enriching and purifying the palbozuril monoclonal antibody drug in serum and plasma by coupling an enrichment reagent I with magnetic beads, magnetically separating the enriched blood sample, discarding the supernatant, adding a buffer solution I for leaching, and adding a buffer solution II for diluting after leaching; the method comprises the following steps: carrying out high-temperature denaturation on a diluted blood sample, sequentially adding an internal standard and protease for enzymolysis, and then adopting a high performance liquid chromatography-tandem mass spectrometry to realize high-sensitivity rapid detection of the drug concentration of the palbozuril monoclonal antibody in the blood sample. In the pretreatment process, the steps of protein reduction and alkylation are removed, the proteolysis time is shortened, the whole process is simple, convenient and rapid, and multiple requirements of clinical detection on timeliness, accuracy and low detection cost can be met at the same time.

The invention relates to a primer probe set for quantifying HIV-1 (human immunodeficiency virus-1), which comprises an internal standard primer probe set for amplification in the same environment and a target primer probe set corresponding to a specific conserved region sequence of HIV-1, and the internal standard primer probe set and the target primer probe set are configured as follows: the difference between the target probe and the internal standard probe does not exceed 5 DEG C according to the fusion degree; the melting temperature of the internal standard probe is 5-10 DEG C higher than that of the internal standard upstream and downstream primers. Through multi-target design, primer probe optimization, amplicon sequence control and interior label universality improvement, the accuracy, sensitivity and universality of HIV-1 detection are remarkably improved, meanwhile, the development cost and the use complexity are reduced, and the kit has important clinical application value.

The invention discloses an ultratrace mercury isotope analysis method, and relates to the technical field of environmental analysis. The method comprises the following steps: purging a liquid sample to be detected by nitrogen in a stannous chloride atmosphere, and trapping and concentrating mercury into a gold trapping tube; pyrolyzing the pyrolytic gold trapping tube to release mercury vapor; pyrolytic mercury vapor and thallium isotope internal standard aerosol are mixed to serve as a sample injection sample, and the sample injection sample is introduced into a multi-receiver inductively coupled plasma mass spectrometry; acquiring a mercury instantaneous signal and a thallium isotope signal; and calculating the mercury isotope ratio by adopting least square linear regression fitting in combination with a thallium internal standard ratio correction algorithm. According to the method, the instantaneous mercury isotope signal is generated by online combination of gold trapping and multi-receiver inductively coupled plasma mass spectrometry, the instantaneous signal is strategically collected and processed, the determination concentration of isotope analysis can be greatly reduced, the sensitivity of the method is remarkably improved, and direct determination of mercury isotope composition in a water sample with the concentration of 10 ng L <-1 > is met.

The present invention relates to a method for quantitatively analyzing the concentration of lencanezumab in blood based on liquid chromatography-tandem mass spectrometry, wherein a serum sample is pretreated to obtain a characteristic peptide segment, and the characteristic peptide segment is quantified by an internal standard method combined with liquid chromatography-tandem mass spectrometry technology, thereby quantifying the content of lencanezumab in blood. The method of the present invention detects the concentration of lencanezumab with high sensitivity and high specificity, and the accuracy and precision meet the requirements. It can be used for the quantitative analysis of lencanezumab in serum, and provides a reliable detection method for monitoring the concentration of lencanezumab, thereby guiding its clinical use.

The present invention provides a detection method for free testosterone and total testosterone concentration, including antibody-coupled magnetic micro-enrichment of free testosterone and total testosterone in serum samples using a kit, automated pre-treatment and LC-MS / MS detection, the kit includes a testosterone separation and purification reagent strip, a testosterone calibration curve and a testosterone quality control product, and a testosterone separation and purification reagent strip includes testosterone antibody-coupled magnetic particles, testosterone stable isotope internal standard, eluent and eluent that can separate and purify testosterone. The present invention combines the advantages of immunoassay and mass spectrometry, and the required reagents for separating and purifying testosterone are prepared into closed reagent strips, effectively avoiding experimental errors caused by poor contamination of reagents. The sample is added to the reagent strip, and the pre-treatment is automated, and the operation process only requires 12min, completes the extraction of testosterone in the sample, and the treated sample is taken out for detection, without the need for various reagents, consumables, instruments and equipment commonly used in conventional detection methods and their placement space, simple and efficient, easy to clinical detection and application.

The invention discloses a method for quantitatively testing trimethyl phosphate by nuclear magnetic resonance spectroscopy, which relates to the technical field of chemical detection and comprises the following steps: weighing a quinalphos internal standard substance and dissolving the quinalphos internal standard substance in deuterated methanol to prepare an internal standard substance solution for later use; the method comprises the following steps: adding a trimethyl phosphate sample into deuterated methanol, respectively preparing solutions with different concentration gradients, adding an internal standard substance solution, respectively measuring integral areas of a measured sample and an internal standard substance, drawing a concentration configuration marking line, and calculating a linear regression equation; the method comprises the following steps: preparing a quinalphos standard solution and a candidate sample solution by using the same solvent and internal standard substance by using a phosphorus spectrum nuclear magnetic quantitative method, carrying out sample introduction analysis on the candidate sample solution, and testing the integral area of trimethyl phosphate and quinalphos; and calculating the content of trimethyl phosphate.

The invention discloses a method for detecting soil active organic carbon based on fluorescence spectrometry, and belongs to the technical field of soil detection. The method comprises the following steps: sequentially drying, sieving and grinding fresh soil to obtain a soil sample, and sequentially performing active organic carbon extraction, purification, decoloration and pH regulation on the soil sample to obtain a soil liquid to be detected. The method comprises the following steps: adding fluorescein into a soil liquid to be detected to form a soil internal standard detection liquid, obtaining a soil fluorescence spectrum through three-dimensional fluorescence spectrum scanning, carrying out background deduction and correction coefficient correction, and calculating the active organic carbon concentration of the soil by using tryptophan, tyrosine and SMP fluorescence concentration standard curves. According to the method, an internal standard method is combined with a fluorescence spectrum technology, and through multi-step sample pretreatment and spectrum correction, the detection accuracy and the anti-interference capability are improved, the active organic carbon concentration of the soil can be rapidly and accurately determined, and an effective means is provided for soil carbon cycle research and quality evaluation.

The invention provides a quantitative NMR (nuclear magnetic resonance) carbon spectrum valuing method of an azide polyether branching degree standard substance, which is based on quantitative NMR and directly values the branching degree of the azide polyether branching degree standard substance under the condition of not using an internal standard substance. Compared with the existing branching degree valuing method, such as a differential scanning calorimetry and a gel chromatography, the valuing method disclosed by the invention does not need an internal standard or an external standard, does not need to establish a calibration measurement curve, is simple and convenient in data processing and calculation, high in detection sensitivity and good in valuing accuracy, can realize unattended operation and stable operation in the testing process, and is suitable for large-scale popularization and application. The method is suitable for valuing the azide polyether branching degree standard substance.

The invention discloses a method for detecting trace chromium element in copper foil based on ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer), which comprises the following steps: soaking a lithium battery copper foil in a mixed solution of concentrated nitric acid and hydrofluoric acid for high-temperature digestion, adding a scandium internal standard solution, and fixing the volume to obtain a solution to be detected; preparing a mixed standard solution of chromium element and scandium element with a plurality of concentration gradients, and establishing a standard curve through ICP-OES; and determining the content of the chromium element in the to-be-detected solution according to the standard curve. The lithium battery copper foil is digested through a mixed acid system, concentrated nitric acid provides an acid environment and an oxidation effect, hydrofluoric acid promotes dissolution, it is ensured that the copper foil is completely dissolved, and the digestion efficiency is improved; a scandium internal standard method is introduced, a dynamic background correction mode of ICP-OES is adopted, a scandium internal standard element can correct signal fluctuation in a sample introduction process, dual guarantee is formed by the scandium internal standard element and dynamic background correction, interference of a copper matrix on a Cr spectral line is specifically eliminated, and the trace chromium element detection precision is remarkably improved.

The present invention discloses a method for measuring the hydroxyl value of a polyether polyol using nuclear magnetic resonance phosphorus spectroscopy, comprising: 1) adding a polyether polyol sample to be tested and an internal standard bisphenol A to a deuterated reagent and dissolving them by ultrasonication; 2) adding a phosphorus oxychloride compound and an acid binding agent to the mixture and allowing them to react fully to obtain corresponding different derivatized phosphorus-containing products; 3) performing a phosphorus spectroscopy test in a nuclear magnetic resonance analyzer to obtain nuclear magnetic resonance phosphorus spectroscopy data, processing and analyzing the data, integrating the nuclear magnetic resonance characteristic peak areas of the phosphorus-containing products after derivatization of the polyether polyol sample and the internal standard bisphenol A, and normalizing them to 100%, and calculating the hydroxyl value of the sample to be tested based on the molar ratio relationship between the products. The hydroxyl value result obtained by the present method has a relative deviation of less than 5% from the result obtained by the phthalic anhydride acylation method in the national standard GB / T 12008.3-2009, and the two results are close and highly accurate. The analytical testing method of the present invention is simple, has low pollution, and is short in time.

The invention discloses a method for detecting 18 phthalic acid ester substances in brewed sauce, which specifically comprises the following steps: step 1, obtaining a sample of the brewed sauce to be detected, adding a phthalic acid ester substance internal standard working solution containing deuterated isotope and water, uniformly mixing, adding sodium chloride and acetonitrile, continuously uniformly mixing, and detecting the content of the phthalic acid ester substances in the brewed sauce to be detected; carrying out ultrasonic extraction treatment for 5-15 minutes, adding an ultrasonic extracting solution into a mixture of PSA, C18 and MgSO4, and carrying out centrifugal treatment to obtain supernate; 2, carrying out nitrogen blowing on the supernate until the supernate is nearly dry, and fixing the volume by using normal hexane to obtain a sample to be detected; and step 3, detecting by adopting a gas chromatography-tandem mass spectrometer isotope internal standard method.

A method for detecting the content of fluralana based on cat plasma relates to the technical field of detection of the content of fluralana, and comprises the following steps: extracting fluralana in a cat plasma sample by using an acetonitrile precipitation method, adding isotope deuterium-labeled fluralan-D4 as an internal standard, and quantifying the fluralana by using a UPLC-MS / MS method, verification parameters such as the quantitative range, the minimum quantitation limit, the intra-day and inter-day accuracy and precision of the analyte fluralana in the cat plasma and the selectivity and the recovery rate of the method all meet the requirements; after ULOQ is measured every time, an acetonitrile sample is continuously injected, the analyte residual quantity meets the requirement, the established method for measuring the flurala in the plasma through LC / MS / MS meets the requirement of the related guiding principle, the method is applied to the pharmacokinetics method of the flurala drops in the cat body, and the content of the flurala in the cat plasma sample can be accurately quantified.

The invention discloses an analysis method for simultaneously detecting organochlorine pesticide and polychlorinated biphenyl, which comprises the following steps of: simultaneously extracting organochlorine pesticide and polychlorinated biphenyl in a water sample by adopting a mixed extraction solvent, dehydrating, concentrating and fixing the volume of extract liquor, separating and measuring by adopting a gas chromatography-mass spectrometry method, and quantifying by adopting an internal standard method. When the mixed extraction solvent is n-hexane / dichloromethane with the volume ratio of 9: 1 and 1% by mass of polyethylene glycol 4000 is added, the recovery rates of water samples with the measured concentrations of 5.00 ng / L, 20.0 ng / L, 40.0 ng / L and 80.0 ng / L are 83.6%-95.4%, 91.2%-105.6%, 93.5%-104.7% and 92.8%-106.9% respectively, the relative standard deviations are 6.1%-9.2%, 3.3%-8.2%, 3.2%-6.3% and 3.4%-7.5% respectively, compared with the prior art, the extraction efficiency is remarkably improved, and the method has the advantages that the method is simple, the cost is low, and the method is suitable for industrial production. The accuracy and precision of the method completely meet the determination and analysis requirements for measuring complex water samples.

The invention discloses a method for detecting the content of tributyl phosphate in salt lake brine, and belongs to the field of environmental chemical analysis and detection. The method for detecting the tributyl phosphate in the salt lake brine specifically comprises the following steps: transferring the salt lake brine, adding water, diluting and uniformly mixing to obtain a sample solution; then loading the sample solution to an activated C18 solid-phase extraction column, leaching with water, discarding effluent, eluting with an acetone ethyl acetate solution, collecting eluant, blowing to be nearly dry, redissolving, and passing through a membrane to obtain a to-be-detected sample, determining by adopting GC / MS, and calculating to obtain the content of tributyl phosphate in the to-be-detected sample according to a standard curve model of an internal standard method. The method has good sensitivity, stability and repeatability, is suitable for accurate determination of tributyl phosphate in salt lake brine, and provides necessary technical support for detection and monitoring of salt lake brine pollutants.

The invention discloses a method for determining the content of trace holmium, thulium and tungsten in rare earth erbium and a compound thereof, which comprises the following steps: placing a rare earth erbium and compound sample thereof in a beaker, and performing a blank test along with a sample; adding nitric acid, heating at low temperature until the sample is completely dissolved, and cooling; transferring into a volumetric flask, adding a cesium internal standard solution, diluting with water, and uniformly mixing; the holmium, the thulium and the tungsten are measured by using an oxygen mode of an inductively coupled plasma tandem mass spectrometer, and the contents of the holmium, the thulium and the tungsten are calculated according to a working curve method. According to the method, the inductively coupled plasma tandem mass spectrometry technology is used, and mass spectrum interference of an erbium matrix on holmium, thulium and tungsten is effectively eliminated by selecting a proper reaction mode and optimizing the flow of reaction gas.

The invention relates to the technical field of tobacco leaf element analysis, in particular to a detection method for volatile compounds in tobacco leaves and a clustering analysis method for the tobacco leaves. The method for detecting the volatile compounds in the tobacco leaves comprises the following steps: drying and pulverizing tobacco leaves to be detected to prepare sample powder of the tobacco leaves to be detected; extracting the mixed solution of the tobacco leaf sample powder to be detected and the internal standard solution by adopting a headspace solid-phase microextraction method to prepare an extracting solution; carrying out gas chromatography-mass spectrometry detection on the extract liquor; wherein an extraction head used by the headspace solid-phase microextraction method is a divinylbenzene / carbon molecular sieve / polydimethylsiloxane composite coating extraction head, and the parameters of the headspace solid-phase microextraction method are as follows: the extraction temperature is 75-85 DEG C, the extraction time is 45-55 minutes, the desorption time is 4-6 minutes, and the equilibrium time is 3-7 minutes. The method for detecting the volatile compounds in the tobacco leaves, provided by the invention, can effectively separate and analyze the volatile components, and is simple and efficient.

The invention relates to the technical field of heavy metal detection, in particular to a method for detecting heavy metal in water by combining membrane evaporation drying and a monochromatic aggregation X-ray fluorescence spectrophotometer, which comprises the following steps: (1) taking a certain volume of water sample, and adding an internal standard; (2) placing a polyamide membrane at the pretreatment position, and carrying out evaporation drying treatment, so that heavy metal elements in the water sample are enriched on the polyamide membrane in the form of solid residues; (3) taking out the polyamide membrane, performing X-ray radiation on solid residues on the polyamide membrane, and collecting fluorescence signals of heavy metal elements; and (4) carrying out qualitative and quantitative analysis on the heavy metals in the water sample by combining an internal standard algorithm with a fluorescence signal. According to the method disclosed by the invention, the heavy metals in the water are detected by combining membrane evaporation drying and a monochromatic gathering X-ray fluorescence spectrometer, and the 0.1 ppb-level analysis level of the heavy metals in the water sample can be realized by combining a membrane enrichment method.

The invention relates to a method for detecting perfluorinated compounds in water, which comprises the following steps: carrying out solid-liquid separation on a water sample to prepare a liquid to be detected; carrying out on-line solid phase extraction-liquid chromatography-mass spectrometry detection on the to-be-detected liquid, and calculating the content of the perfluorinated compounds in the to-be-detected liquid by an internal standard method. The detection method is high in automation degree, simple and rapid to operate and capable of accurately detecting the perfluorinated compounds in the water.

The invention belongs to the technical field of biological detection, and particularly relates to a method for synchronously and quantitatively detecting various folic acid metabolism related substances in trace plasma or serum, which comprises the following steps of: detecting a pretreated trace plasma or serum sample by adopting a liquid chromatography-tandem mass spectrometry method; the following nine folic acid metabolism related substances are synchronously and quantitatively detected: 5-formyl tetrahydrofolic acid, folic acid, 5-methyl tetrahydrofolic acid, S-adenosine-L-methionine, S-adenosine-L-homocysteine, vitamin B12, pyridoxamine, pyridoxine and pyridoxal. The invention further relates to application of the detection method in related detection of child neurodevelopment. According to the detection method, only trace plasma or serum is used, methotrexate is used for replacing an expensive isotope internal standard for more economical detection, and nine folate metabolism related substances can be accurately quantified at the same time. Therefore, the detection method disclosed by the invention has important clinical significance and wide market application prospect.

The invention discloses an ethylene oxide detection and analysis method, which belongs to the technical field of detection and analysis, and comprises the following steps: weighing a sample to be detected, adding deuterated internal standard ethylene oxide-D4, and dissolving the sample with a low-temperature mixed solvent to obtain a sample solution; uniformly mixing the sample solution, adding a purifying material for purifying, uniformly mixing and centrifuging to obtain supernate; putting a part of the supernate into a small solid-phase microextraction bottle, adding sodium chloride, and uniformly mixing to obtain a solution to be detected; placing the small solid-phase microextraction bottle filled with the solution to be detected on a gas chromatograph-tandem mass spectrometer with a CTC automatic solid-phase microextraction sampling device, and extracting and detecting the prepared solution to be detected; and analyzing the data acquired by the mass spectrum by utilizing Agilent MassHunter data processing software. According to the method, volatile components in a sample are enriched, concentrated and then detected, the residual amount of ethylene oxide in the fat-soluble plant extract can be directly and quantitatively analyzed, the sensitivity is high, and the accuracy is good.

The invention discloses a method for accurately measuring trace calcium in high-purity magnesium metal by combining membrane desolvation and triple quadrupole mass spectrometry, which comprises the following steps: (1) sequentially adding water to wet a high-purity magnesium sample and adding acid to dissolve the sample to obtain a digestion solution, and adding an internal standard solution into the digestion solution; (2) preparing calcium element solutions with multiple concentration gradients, adding the internal standard solution, fixing the volume, and shaking uniformly; (3) sequentially carrying out atomization treatment and membrane desolvation treatment on the prepared solution to respectively obtain dry aerosol of the to-be-detected solution and the standard solution; and (4) carrying out scanning determination on the dry aerosol of the solution to be detected and the standard solution in the step (3) by using a triple quadrupole mass spectrometer, and calculating to obtain the calcium content in the high-purity magnesium sample. According to the method, the 24Mg16O polyatomic interference brought by the matrix element and the mass spectrum interference of the working gas Ar on the to-be-detected element 40Ca are removed through membrane desolvation and triple quadrupole mass spectrometry, so that the trace calcium element in the high-purity magnesium sample can be accurately determined, and the lower determination limit can reach ppb level.

The invention relates to the technical field of chemical detection, in particular to a sample pretreatment method and a GC-MS (Gas Chromatography-Mass Spectrometer) method for simultaneously detecting glycidol and monochloropropanol in heated cigarette aerosol. The sample pretreatment method for simultaneously detecting the glycidol and the monochloropropanol in the heated cigarette aerosol comprises the following steps: capturing particulate matters in the heated cigarette aerosol; mixing the trapping material with ethyl acetate and an internal standard substance, extracting to obtain an extracting solution, and diluting with n-hexane; adding heptafluorobutyrylimidazole to perform derivatization reaction, washing with water after the derivatization reaction is completed, and drying to obtain a solution to be detected. According to the present invention, ethyl acetate is adopted for extraction, and detection analysis can be performed through dilution, HFBI derivatization, water washing and drying, such that the sample pretreatment step is substantially simplified, and the analysis sensitivity and the accuracy of the simultaneous detection of the three compounds such as the glycidyl, the 3-chloro-1, 2-propylene glycol and the 2-chloro-1, 2-propylene glycol can be easily improved.

The application provides a pretreatment and detection method of tetrabromobisphenol A and ten common derivatives thereof in sludge, which comprises the following steps: (1) sample pretreatment: after mixing the frozen and dried sludge sample and the isotopic internal standard, oscillation extraction is carried out, and the extraction liquid is obtained after centrifugation by a centrifuge; the extraction liquid is purified by solid phase extraction to obtain a sample to be detected; (2) the sample to be detected obtained in the step (1) is detected by high performance liquid chromatography-tandem mass spectrometry; (3) the content of tetrabromobisphenol A and ten common derivatives thereof in the sample is calculated according to the internal standard method. The application provides a rapid and sensitive analysis and quantitative method of tetrabromobisphenol A and ten common derivatives thereof in sludge samples.