443 results about "Internal standard" patented technology

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 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 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.

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 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 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.

The invention belongs to the technical field of biological drug analysis, and particularly relates to a method and a system for quantitatively detecting antibody drugs by using a dimethyl-labeled modified peptide fragment as an internal standard. Sequentially carrying out dimethyl labeling on the enzymolysis peptide fragments of the antibody drugs to obtain a plurality of dimethyl-labeled modified peptide fragments which are used as internal labels; the method comprises the following steps: enriching antibody drugs in a biological sample, and carrying out enzyme digestion to obtain a plurality of unlabeled modified peptide fragments; and mixing the unlabeled modified peptide fragment with an internal standard, enriching the modified peptide fragment, and then carrying out quantitative detection on the modified peptide fragment by adopting liquid chromatography-tandem mass spectrometry. A one-to-one structural analogue internal standard is provided for the modified peptide fragment, and the matrix effect is eliminated. Meanwhile, the method is combined with a high-pH reversed-phase grading equal peptide fragment enrichment method, so that the detection sensitivity of the modified peptide fragments in the matrix is improved. The technology provides a sensitive and reliable quantitative analysis method for the modified peptide fragment, and can be used for quantitative analysis of antibody drugs in biological samples.

The invention provides a method for detecting the content of elements in carbonized resin. The method comprises the steps of resin pretreatment, instrument tuning, standard curve drawing, sample detection and the like. The method comprises the following steps: firstly, transferring a certain amount of dry carbonized resin into a cleaned PFA digestion tank, adding high-purity mixed acid, setting a segmented heating program to start microwave digestion, cooling to room temperature after digestion is completed, adding a proper amount of ultrapure water to dilute a digestion solution, and adding an internal standard solution and a chemical additive to obtain a to-be-detected sample solution; preparing a multi-element mixed standard solution according to the sample element types, adding the standard solution into the sample solution, and measuring the signal intensity ratio R of the to-be-measured element to the internal standard in each solution; and drawing a standard curve by taking the labeling concentration as a horizontal coordinate and R as a vertical coordinate, correcting the standard curve, and detecting the sample to be detected. The method is used for detecting the content of elements in carbonized resin, the carbonized resin is digested through microwaves, and the obtained solution is clear and can be directly subjected to ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer) detection.

The invention belongs to the technical field of teenager depression marker detection, and particularly relates to a teenager depression marker detection kit and a teenager depression marker detection method, the kit comprises an extraction liquid, an internal standard substance, a quality control substance and a mobile phase additive, the internal standard substance comprises a stable isotope labeled metabolic marker, the quality control substance comprises a standard metabolic marker, and the mobile phase additive comprises a mobile phase. The detection method comprises the following steps: S1, dissolving an internal standard substance by using a methanol-containing aqueous solution to prepare an internal standard stock solution; s2, methanol is added into the internal standard stock solution for dilution, uniform mixing is performed, and an extraction working solution is prepared; s3, taking a quality control product / sample, adding an extraction working solution, carrying out oscillation incubation, centrifuging, and taking supernate as a to-be-detected sample; s4, the sample to be detected is detected through a liquid chromatograph-mass spectrometer, various biomarkers related to depression in the body of the teenager can be rapidly and accurately detected, and an objective and reliable basis is provided for early diagnosis and illness state evaluation of the depression of the teenager.

The present invention discloses a method for quantitative determination of trace harmful elements in various flotation products of rare polymetallic ores, which includes three parts: sample processing, preparation of complex matrix standard solution and sample testing. Each flotation product is digested with analytically pure concentrated nitric acid; the main mineral species of each product are determined by XRD, and the high-purity standard substances of each main associated mineral are digested with analytically pure concentrated nitric acid, and the content of harmful elements to be monitored is determined by ICP-MS after appropriate dilution; each standard substance digestion solution is diluted to a major element concentration of 1000μg / mL, and used to dilute the harmful element standard stock solution to obtain standard solutions with different concentration gradients; then the process blank and digestion sample are tested using an inductively coupled plasma mass spectrometer using a combination of internal standard method and matrix matching to obtain the content of trace harmful elements to be measured. It effectively overcomes the mass spectrometry and non-mass spectrometry interference problems faced by complex matrix sample testing, is suitable for the analysis and testing of trace element content in complex samples, and has a simple method and is easy to operate.

The invention discloses a method for detecting exogenous amylase derived from aspergillus in honey and application of the method. The method comprises the following steps: screening and determining a characteristic peptide fragment, pre-treating a sample, making a standard curve, separating by using liquid chromatography, detecting by using tandem mass spectrometry, and quantifying by using an internal standard method. The exogenous amylase characteristic peptide fragment derived from aspergillus is FASYTNDIALAK, and the specific peptide fragment derived from aspergillus is FASYTNDIALAK. The invention establishes a quantitative method for detecting the exogenous amylase derived from aspergillus in the honey by liquid chromatography-tandem mass spectrometry, and the quantitative method has better accuracy and sensitivity and is suitable for adulteration identification of the honey. The method has important practical significance for controlling the quality of honey and maintaining the healthy and sustainable development of the bee product industry.

The invention discloses a qualitative and quantitative detection method for vitamin A and vitamin E in food. The qualitative and quantitative detection method comprises the following steps: step 1, pre-treating a sample and accurately adding an isotope internal standard: adding d6-alpha-tocopheryl acetate and d8-retinol acetate into the sample before saponification and preparing a blank matrix; 2, pre-treatment parameter QbD-DOE collaborative optimization, wherein a response surface method is adopted for conducting center composite design on the saponification temperature, time and BHT concentration, and the interaction effect of all the factors is analyzed to determine an optimal operation window; step 3, intelligently optimizing chromatography-mass spectrometry conditions and tuning parameters; step 4, constructing a matrix matching calibration curve and performing WLS quantitative analysis: performing gradient dilution on a standard substance by utilizing a blank matrix extracting solution, adding an isotope internal standard to prepare a 5-7-point matrix matching calibration curve, fitting the curve by adopting a weighted least square method, and verifying the correlation and intercept change of the calibration curve every day; and 5, multi-dimensional qualitative confirmation and intelligent diagnosis system operation.

The invention provides a method for determining the quality and purity of gold and silver in a gold and silver commemorative coin, and belongs to the field of analysis and detection. Wherein gold and silver in the gold and silver commemorative coin are separated to obtain a gold sample and a silver sample, the gold sample and the silver sample are weighed respectively, and finally, an equivalent concentration deduction method and an internal standard method are combined to measure the purity of the gold sample and / or the silver sample. The method for measuring the purity of the gold sample comprises the following steps: respectively preparing a solution A1, a solution A2 and a standard solution A3n; determining the impurity element concentrations C1i and C2i in the solution A1 and the solution A2 by using an ICP-AES spectrometer; and omega Au is calculated. The method for measuring the purity of the silver sample comprises the following steps: respectively preparing a solution B1, a solution B2 and a standard solution B3n; determining the impurity element concentrations D1j and D2j in the solution B1 and the solution B2 by using an ICP-AES spectrometer; and omega Ag is calculated. The method is beneficial for improving the quality and purity measurement precision of gold and silver in the gold and silver commemorative coin.

The invention discloses a chlorpromazine-d6 compound as well as hydrochloride, a preparation method and application thereof, and belongs to the technical field of organic synthesis and analysis detection, the chlorpromazine-d6 compound is 3-(2-chloro-10-phenothiazinyl)-N, N-bis (methyl-d3)-1-propylamine, and the preparation method comprises the following steps: taking 2-chlorophenothiazine as a raw material, adding a catalyst, and reacting at the temperature of 60-80 DEG C for 1-2 hours to obtain the chlorpromazine-d6 compound. Carrying out aza-Michael addition and reductive amination reaction to finally obtain chlorpromazine-d6; the obtained chlorpromazine-d6 is subjected to hydrochloric acid acidification, such that chlorpromazine-d6 hydrochloride is obtained; the invention provides a novel deuterated internal standard substance for analysis and detection. In addition, the invention provides a new process for preparing chlorpromazine-d6 and hydrochloride thereof with proprietary intellectual property rights, the preparation method is novel, and has the advantages of simple operation, mild reaction conditions, short process route, high efficiency, low cost, environmental protection and the like; the obtained chlorpromazine-d6 and the hydrochloride thereof have the advantages of high chemical purity, high deuteration rate, high deuterium atom stability and the like.

A method for optimizing at least one parameter setting of at least one mass spectrometry device (110) operating at unit resolution is disclosed. The method comprises the following steps:a) determining at least one analyte detection window for detecting an analyte of interest with the mass spectrometry device (110), wherein the analyte detection window is defined by a central mass to charge ratio value of the analyte and a predefined width, wherein the central mass to charge ratio value of the analyte is set to a theoretical mass to charge ratio value of the analyte of interest having more than one decimal place and / or a mass to charge ratio value of the analyte of interest determined by a high resolution mass spectrometry measurement having more than one decimal place;b) determining at least one internal standard detection window for detecting an internal standard substance with the mass spectrometry device (110), wherein the internal standard detection window is defined by a central mass to charge ratio value of the internal standard substance and the pre-defined width, wherein the central mass to charge ratio value of the internal standard substance is set to a mass to charge ratio value of the internal standard substance calculated relative to the analyte of interest and having more than one decimal place and / or to a mass to charge ratio value of the internal standard substance determined by a high resolution mass spectrometry measurement having more than one decimal place.

The present application relates to the field of analytical chemistry, in particular to a method for detecting ten tobacco alkaloids in soil, which uses sodium hydroxide solution and acetonitrile to extract alkaloids in a soil sample, and uses ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to analyze and detect nicotine, nornicotine, myosmine, pseudotropine, anatabine, anabasine, 2,3'-bipyridine, noranatabine, N-methyl pseudotropine and nornicotine, and uses an internal standard method for quantitative analysis. The present application uses sodium hydroxide solution as an alkaloid eluent and acetonitrile as an extractant, which reduces the amount of solvent used, optimizes the operation process, uses sodium chloride to separate the organic phase and the aqueous phase, improves the sample pretreatment efficiency, uses ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to target analysis of 10 tobacco alkaloids, greatly improves the detection sensitivity, and has strong quantitative ability in targeted analysis.

The application discloses a method for determining unbound concentration of lenvatinib, which comprises the following steps: sending standard curve working solution and quality control working solution into a liquid chromatography tandem mass spectrometry detection system to obtain a standard curve; adding a plasma sample into an ultrafiltration tube, centrifuging under the condition of a centrifugal force of 3000g for 15 min, and collecting an ultrafiltrate of the plasma sample; adding the ultrafiltrate of the plasma sample into blank plasma ultrafiltrate, mixing uniformly, taking supernatant into a collection plate, sending the collection plate into the liquid chromatography tandem mass spectrometry detection system to obtain a ratio of a peak area of lenvatinib to a peak area of an internal standard, and then bringing the area ratio into the standard curve to obtain the unbound concentration of lenvatinib in the plasma sample. The method for determining the unbound concentration of lenvatinib can accurately determine the unbound concentration of lenvatinib in plasma and overcome the prejudice of the prior art.

The application relates to the technical field of analytical chemistry detection, and specifically discloses a rare earth ion chromatographic online analysis and detection method and system, which adopts a chromatography-mass spectrometry combined system, realizes multi-scale time-frequency decomposition of signals by constructing an adaptive wavelet base function library, accurately identifies and classifies interference types in combination with a convolutional neural network and vacuum degree coupling analysis; a U-Net generator with an attention mechanism and a multi-scale discriminator are designed for signal repair aiming at repairable interference; a state transition model containing a mass-to-charge ratio database is established, empirical mode decomposition and adaptive filtering technology are used to realize dynamic calibration of a mass axis; quantitative accuracy is ensured through double internal standard correction and a triple verification mechanism; when unrepairable interference is detected, a hierarchical self-checking program is started, and fault diagnosis is carried out in combination with spectrum fingerprint analysis.

The invention belongs to the technical field of chemical screening, and particularly relates to a systematic screening method for rubber-related chemicals in a plasma sample, which comprises the following steps: S1, taking the plasma sample, adding a mixed extraction solvent, extracting, centrifugally layering, collecting supernate, repeatedly extracting, merging the supernate, concentrating, and freezing to obtain a rubber-related chemical sample; centrifuging again, adding an isotope internal standard, and carrying out data dependence acquisition in a positive and negative ion analysis mode by adopting liquid chromatography-tandem high-resolution mass spectrometry. According to the invention, the comprehensive coverage type monitoring of 1300-1500 RDCs in the plasma sample is realized. By means of combination of a positive and negative ion double analysis mode and data dependence acquisition, the detection range and the signal response stability of the RDCs with different polarities are effectively considered, and the technical problem that in the prior art, the composite effect generated by coexistence of multiple RDCs is ignored is solved.

The invention belongs to the technical field of medicine detection, and particularly relates to an ICPMS (Inductively Coupled Plasma Mass Spectrometry) detection method for element impurities in theophylline. The linear test solution, the blank solution and the theophylline test solution are subjected to ICPMS detection, the content of element impurities in the theophylline test solution is calculated according to an internal standard curve method, and the element impurities are one or more of cadmium, lead, arsenic, mercury, cobalt, vanadium, nickel, lithium, antimony or copper. The method is good in reproducibility and stability, high in accuracy and high in precision.

The invention discloses a method for determining a quaternary ammonium salt pesticide in blood by using liquid chromatography-mass spectrometry, which comprises the following steps of: drawing a whole blood (plasma and serum) matrix labeling standard working curve through liquid chromatography-mass spectrometry analysis; obtaining peak areas of quantitative ion peaks of target objects containing paraquat, aquacide, diguat, chlormequat and mepiperidine with different concentrations and peak areas of quantitative ion peaks of internal standard substances, and further drawing a standard working curve; and performing liquid chromatography-mass spectrometry analysis on the whole blood sample under the same condition to obtain the peak area of a target substance quantitative ion peak and the peak area of an internal standard substance quantitative ion peak in the whole blood test solution, and calculating the content of each quaternary ammonium salt pesticide according to the standard working curve. The method can be used for simultaneously detecting the content of five quaternary ammonium salt pesticides in the whole blood of the poisoned patient simply, conveniently and quickly, and has the characteristics of simplicity, accuracy, good repeatability and high sensitivity.

The present application relates to the field of environmental chemistry and biological sample analysis, and particularly relates to an analysis method for detecting organic ultraviolet absorbers and metabolites thereof in urine. The method comprises enzymolysis of a urine sample and addition of an internal standard, extraction and purification of 24 kinds of organic ultraviolet absorbers and metabolites thereof in the sample by extraction, and detection of the content of target substances in the urine sample by high performance liquid chromatography-mass spectrometer. The present application is simple in operation, high in accuracy and reliability, can simultaneously detect 24 kinds of organic ultraviolet absorbers and metabolites thereof in 8 categories at one time, some substances are reported for the first time in the human urine detection method, and the method has wide practical application value and significance for evaluating the residual situation of organic ultraviolet absorbers and metabolites thereof in human body.

The invention discloses a multi-element quantitative analysis method for laser ablation inductively coupled plasma mass spectrometry, and aims to solve the problems that the quantitative process of the existing LA-ICP-MS technology depends on a standard sample, the automation degree is low, and the existing LA-ICP-MS technology cannot adapt to complex multi-element signals. According to the method, full-automatic and multi-element (such as 9 main quantities and 30 trace elements) quantitative analysis is realized in the LA-ICP-MS field without an internal standard and an external standard, the analysis efficiency, the accuracy and the data comparability among different platforms are remarkably improved, and a breakthrough solution is particularly provided for application of element quantitative imaging and the like.

The invention discloses a multi-dimensional high-precision detection method and system for biotoxins in agricultural products, and the method comprises the steps: carrying out sterile collection and grading pretreatment on an agricultural product sample to obtain a homogenized sample; extracting the homogenized sample by adopting a mixed solvent system, adding an internal standard substance, carrying out salting-out layering, and collecting supernate; sequentially carrying out QuEChERS purification, multi-mechanism adsorption column purification and molecularly imprinted polymer specific enrichment on the supernate; carrying out dual-mode detection on the target toxin enrichment liquid, respectively carrying out quantitative detection by adopting a liquid chromatography-tandem mass spectrometry method, and carrying out screening detection by adopting an intelligent electrochemical sensing method; performing optimization processing on the dual-mode detection signal, and comprehensively judging a sample detection result; through integrated application of a triple purification mechanism, a dual-mode detection system, machine learning signal analysis and a full-chain quality control technology, efficient enrichment and deep interference removal of target toxins in a complex matrix can be realized, and both precision and applicability are considered.

The invention discloses a detection method of vitamin K1, and belongs to the technical field of biological detection. The problems that a vitamin K1 detection method is tedious in operation, prone to being influenced by a matrix, low in sensitivity and the like are solved. The detection method comprises the following steps: (1) preparing a standard substance intermediate working solution, an isotope internal standard substance solution and a standard curve working solution of the vitamin K1; (2) treating a serum sample and a standard curve working solution: adding a 2-nitroso pyridine solution to carry out derivatization reaction; and (3) detecting the vitamin K1 by using a high performance liquid chromatography-tandem mass spectrometry method. According to the method, the 2-nitroso pyridine is used as a derivatization reagent, the vitamin K1 and the 2-nitroso pyridine are subjected to a Diels-Alder reaction to generate a new six-membered heterocycle containing N and O, the 2-nitroso pyridine can efficiently and completely react with the vitamin K1 in only 10 minutes at room temperature, the detection steps are simplified, the sample pretreatment time is shortened, and the detection efficiency is improved.

The invention relates to a method for detecting primary metabolites and / or secondary metabolites in flavors and fragrances, which comprises the following steps: (1) mixing flavors and fragrances, an internal standard substance and a solvent, extracting, taking clear liquid, and removing the solvent to obtain a dry product; (2) mixing the dry product, an oximation reagent and a solvent for an oximation reaction, and then mixing a reaction system and a silanization reagent for a silanization reaction to obtain a solution to be detected; the silanization reagent comprises a combination of N-methyl-N-(trimethylsilyl) trifluoroacetamide and N, O-bis (trimethylsilyl) trifluoroacetamide, and the silanization reagent comprises N-methyl-N-(trimethylsilyl) trifluoroacetamide and N, O-bis (trimethylsilyl) trifluoroacetamide; and (3) detecting the solution to be detected by adopting a gas chromatography-mass spectrometry method, and obtaining the content of primary metabolites and / or secondary metabolites in the flavors and fragrances by utilizing an internal standard method. According to the method provided by the invention, the flavors and fragrances are subjected to oximation and silanization treatment, and then the flavors and fragrances are detected by using the gas chromatography-mass spectrometry, so that the metabolites contained in the flavors and fragrances can be precisely and accurately detected.

This application provides a method for simultaneously detecting hydroxy acids and keto acids in a sample. The method includes the following steps: preparing a standard solution; performing ketone and carboxyl derivatization on the sample to be tested containing hydroxy acids and keto acids to obtain the sample to be tested; performing ketone and carboxyl derivatization on the standard solution to obtain a derivatized standard solution; and sequentially adding a ketone derivatization reagent and... 13 The method involves derivatization with a C6-labeled carboxyl derivatization reagent to obtain an isotope internal standard solution. This solution is then added to both the sample to be tested and the derivatized standard solution for LC-MS / MS analysis. The method described in this application achieves unified detection of paired hydroxy acids and keto acids by selectively derivatizing the ketone group followed by the carboxyl group. A sequential derivatization strategy is constructed based on the functional group differences between keto and hydroxy acids, significantly improving the stability, repeatability, and quantitative reliability of keto acid detection while enhancing overall detection sensitivity.

The invention relates to the technical field of analysis and detection, in particular to a method for analyzing an aluminum element in peanut iodized oil. The analysis method specifically comprises the following steps: sample pretreatment: fully reacting a to-be-detected sample with nitric acid, treating the to-be-detected sample in a water bath environment at 80-120 DEG C for 1-2 hours, and then carrying out microwave digestion; after the digestion is completed, treating in a water bath environment at 60-80 DEG C for 1-2 hours, and fixing the volume. Performing inductively coupled plasma mass spectrometry determination: respectively adding internal standard ISTD elements with the same concentration into the standard solution, the test solution and the blank solution, and performing determination; and preparing a standard curve by using the standard solution, and calculating the concentration of the aluminum element in the test solution by using the standard curve. Compared with the prior art, the analysis method provided by the invention not only has lower requirements on the sample dosage, but also has higher accuracy and lower detection limit.

The invention relates to a method for rapidly determining the content of K.2. 2.2. 2 in an FDG card sleeve kit leacheate, and belongs to the technical field of radiopharmaceutical analysis. The method comprises the following steps: selecting a 1110 + / -5 cm <-1 > peak as a quantitative characteristic peak of K.2.2. 2, wherein the peak corresponds to symmetric stretching vibration of a C-O-C ether bond in a K.2.2. 2 molecule; selecting a 2253 + / -3cm <-1 > peak as an internal standard peak, wherein the peak corresponds to C = N triple bond stretching vibration of acetonitrile in the leacheate; preparing a K.2. 2.2. 2 gradient solution with the concentration of 0.05 to 5 mg / mL, and fixing the concentration of K2CO3 to be 0.5 to 2 mg / mL; the method comprises the following steps: acquiring a spectrum by adopting an ATR technology, setting the resolution ratio to be 4cm <-1 > and the scanning frequency to be 32, and establishing a K.2. 2.2. 2 linear model according to the ratio of A1110 / A2253; eliminating baseline drift by adopting a second derivative spectrum; and a PLS algorithm is adopted to correct trace interference of K2CO3.