17 results about "Amino acid analysis" patented technology

The invention relates to the technical field of detection of amino acid components in fermented soybean, in particular to a method for determining the content of amino acid components in fermented soybean. Comprising the following steps: (1) preparing a fermented soybean sample into a fermented soybean extraction solution; (2) preparing a fermented soybean test solution from the fermented soybean extraction solution; (3) diluting the amino acid solution into different concentration gradients to obtain a mixed amino acid reference substance solution; preparing the mixed amino acid reference substance solution into an amino acid derivatization reference substance solution; (4) preparing a blank derivatization reagent from the hydrochloric acid solution by using the derivatization reagent; and (5) carrying out ultra-high performance liquid chromatography on the fermented soybean test solution, the amino acid derivatization reference substance solution and a blank derivatization reagent. The invention provides an efficient, accurate and reliable method for amino acid analysis of fermented soybean and other fermented food, and the method has important significance for improving the product quality, optimizing the production process and promoting related research.

This application discloses a method for determining the standard value of neuron-specific enolase (NSE) solution, belonging to the field of biotechnology. The determination method provided in this application includes characterizing the physicochemical properties of the NSE standard candidate solution, such as purity, molecular weight, secondary structure, and bioactivity; diluting and dispensing the NSE standard candidate solution; accurately determining the content of the NSE standard candidate solution and verifying its homogeneity and stability using isotope dilution mass spectrometry based on amino acid analysis and characteristic peptide analysis; and evaluating the uncertainty of the NSE solution standard value determination results. The determination method provided in this application has good reliability and accuracy, and the determination results are traceable to SI units (mol).

This invention discloses an amino acid assay kit based on the o-phthalaldehyde (OPA) method, its preparation method, and its application. Belonging to the field of amino acid detection and analysis technology, it is used for rapid and accurate quantitative detection of amino acids in samples. The amino acid assay kit can not only measure the total amino acid content but also analyze specific amino acids and dipeptides such as alanine glutamine, meeting diverse analytical needs. This amino acid assay kit is suitable for batch testing and supports high-throughput laboratory applications. By optimizing the reagent formulation and operating procedures, this invention effectively simplifies the detection steps, improves detection sensitivity and specificity, and fills the gap in the market for OPA-based assay kits. This invention can be widely applied in nutrition, medicine, clinical diagnostics, and drug development, providing a convenient and efficient amino acid analysis tool for life science and medical research.

The present application relates to the technical field of bioengineering, and particularly relates to a kind of omega-transaminase mutant and its application.The present application discloses a kind of omega-transaminase mutant and its application in the synthesis of silodosin intermediate, the omega-transaminase mutant is by from Arthrobacter, through homologous modeling, reaction intermediate molecular docking, active site amino acid analysis, homologous sequence analysis, virtual mutation analysis combined with site-directed mutation verification, the single-point mutation of 62th and 223th obtains H62A, S223A mutant.The omega-transaminase mutant of the present application can one-pot catalysis 60mM silodosin intermediate ketone is converted into silodosin intermediate, conversion rate is greater than 92%, compared with wild type, the specific activity of H62A mutant to silodosin intermediate ketone is 1.4 times of wild type, S223A is 1.24 times of wild type, and the optimum reaction temperature is 30 DEG C, and the ee value of product is greater than 99.29%.

The invention discloses a method for realizing ham quality grading based on non-volatile flavor substance analysis, and relates to the field of ham quality grading methods. The invention solves the problems that the existing Xuanwei ham fermentation process is not standard, and the fermentation process cannot be adjusted according to the content of non-volatile compounds and the change rule of the whole taste. The method comprises the following steps: 1, taking naturally fermented mature Xuanwei ham, cutting off an oxide layer, and rapidly separating biceps femoris muscle from semimembranous muscle; and 2, respectively carrying out amino acid determination on the separated biceps femoris muscle and the separated semi-membranous muscle, and grading the quality of the ham according to test data. Through amino acid analysis, accurate evaluation of the quality of the Xuanwei ham is realized. The method is used for Xuanwei ham quality grading.

The application discloses a kind of construction methods, applications and quality detection methods of watermelon frost HPLC characteristic atlas, comprising the following steps: (1) amino acid is selected as reference, and reference solution is prepared;(2) watermelon frost test sample solution is prepared;(3) chromatographic conditions: with amino acid analysis special column as chromatographic column, with acetonitrile-0.1mol / L sodium acetate solution as mobile phase A, with acetonitrile-water as mobile phase B, the volume ratio of acetonitrile and 0.1mol / L sodium acetate solution in the mobile phase A is 7:93, the volume ratio of acetonitrile and water in the mobile phase B is 80:20;Gradient elution is carried out, and the theoretical plate number is not less than 150000 according to valine peak calculation;(4) reference solution and test sample solution are respectively taken, and injected into liquid chromatograph, and determined, and watermelon frost HPLC characteristic atlas is obtained.The method is stable and reliable, can control the quality of watermelon frost as a whole, guarantees product batch stability and consistency.

The utility model discloses a liquid storage device for an amino acid analyzer, and belongs to the technical field of amino acid analysis devices. The liquid storage device for the amino acid analyzer comprises a mounting plate, a threaded column is mounted at the top end of the mounting plate, a bayonet socket is connected to the top end of the threaded column, a jack is formed in the middle of the top end of the bayonet socket, a socket is inserted into the inner side of the jack, a connecting plate is mounted at the top end of the socket, and a connecting column is mounted at the top end of the connecting plate; a liquid storage barrel is installed at the top end of the connecting column, limiting holes are formed in the two sides of the top end of the bayonet socket, limiting columns are installed on the two sides of the bottom end of the connecting plate, the outer sides of the limiting columns are connected with the inner sides of the limiting holes in an inserted mode, cavities are formed in the two sides of the bayonet socket, locking mechanisms used for limiting movement of the socket are arranged on the inner sides of the cavities, and the socket is sleeved with a threaded sleeve. According to the quick disassembly and assembly device for the liquid storage barrel, the quick disassembly and assembly function of the liquid storage barrel can be effectively achieved, a user can conveniently clean the liquid storage barrel, and the quick disassembly and assembly device for the liquid storage barrel has high practical value.

The invention belongs to the technical field of traditional Chinese medicine analysis, and particularly relates to a method for analyzing the amino acid content in donkey hide extract and plasma substituted.The method comprises the following steps that 1, sample pretreatment is conducted, specifically, a sample is treated through microwave-assisted acid hydrolysis, heating is uniform, the hydrolysis efficiency is high, and amino acid in the sample can be fully released; (2) establishment and optimization of a detection method: establishing and optimizing a high performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) non-derivatization analysis method of animal traditional Chinese medicine samples, and realizing simultaneous detection of multiple amino acids; and (3) rapidly determining amino acids in the donkey hide extract and the plasma substitute. According to the method, microwave-assisted acid hydrolysis is adopted, so that the sample treatment efficiency is remarkably improved, HPLC-ELSD non-derivatization detection is easy and convenient to operate, the application range is wide, and the method can be used for simultaneous detection of multiple amino acids in donkey hide extract and plasma substitute samples. The method provides an efficient and accurate detection scheme for animal traditional Chinese medicine amino acid analysis.

To provide a new amino acid analysis method and amino acid analysis device having a better effect.SOLUTION: A method for analyzing an amino acid included in a sample is provided, the amino acid analysis method includes: a measurement step (Step A) of measuring the Raman spectrum (SA) of the sample by using Raman spectroscopy; and an amino acid qualitative analysis step (Step B) of identifying the amino acid based on the wave number (WA) of a peak (PA) appearing according to the component of the amino acid included in the Raman spectrum (SA) of the sample. The amino acid is two or more of cystine, methionine, leucine, isoleucine, valine, tryptophan, histidine, phenylalanine, threonine, tyrosine, serine, lysine, glycine, glutamic acid, arginine, and glutamine.SELECTED DRAWING: None

The presented system introduces a reusable and user-friendly apparatus tailored for the digestion of samples for amino acid assay. This specialized device comprises a purpose built tube crafted from borosilicate glass, accompanied by a cap constructed from polytetrafluoroethylene. The tube is designed with a gas inlet for the introduction of nitrogen gas and a gas outlet to facilitate the expelling of air from the tube, preventing any spillage of the hydrochloric acid used in the sample digestion. A notable feature of the tube's design is its constriction, allowing the cap to establish an airtight seal, effectively sealing off both the gas inlet and gas outlet. By maintaining a nitrogen atmosphere within the tube throughout the digestion process, the risk of oxidation of amino acids is mitigated, ensuring accurate assessment of quantities of amino acids. The apparatus is characterized by its ease of use and reusability, providing a practical solution for digestion of samples for precise and efficient amino acid assay.

The present application relates to the technical field of biometrics and in vitro diagnosis standardization, and particularly relates to a preparation and value determination method of alpha-synuclein solution standard substance, comprising the following steps: cloning a gene coding alpha-synuclein into a prokaryotic expression vector for recombinant expression, purifying the protein raw material with purity greater than or equal to 99% through affinity chromatography and ion exchange chromatography; diluting and sub-packaging the protein raw material for storage to obtain the solution standard substance; determining the value of the standard substance by using an isotope dilution mass spectrometry method based on amino acid analysis, calculating the mass concentration value by measuring the peak area ratio of stable amino acids and isotope-labeled amino acids after hydrolysis, and tracing the value to the international unit system through the amino acid primary standard substance; and performing uniformity testing and stability investigation on the standard substance, solving the problem of lack of standard substance with metrological traceability in the alpha-synuclein detection field, and obtaining the standard substance which can be used for value transmission and detection result standardization among different in vitro diagnosis platforms.

A method for analyzing amino acids by liquid chromatography, in which a sample containing a plurality of kinds of amino acids is derivatized with a derivatization reagent, and the obtained derivatized sample is circulated on a column together with a mobile phase. Two or more kinds of derivatized samples are prepared using two or more kinds of derivatization reagents. Different analytical conditions in which mixing ratio of the plurality of the mobile phases is changed with a passage of time are set for each kind of the derivatization reagent. A solvent mixing ratio in the mobile phase being the mixed solvent system is set for the each kind of the derivatization reagent. The two or more kinds of derivatized samples are analyzed by automatically switching between the different analytical conditions and the solvent mixing ratio to separate and quantify derivatized L-amino acids and derivatized D-amino acids.

The invention relates to the technical field of amino acid analysis and detection, and particularly discloses a method for synchronously detecting main components of amino acid and impurity amino acid. Comprising the following steps: preparing a mobile phase solution which comprises a mobile phase B1 to a mobile phase B5; preparing a ninhydrin reaction solution and a ninhydrin buffer solution; carrying out gradient elution on a to-be-detected sample on a cation exchange chromatographic column by using the mobile phase solution, and separating the amino acid main component from the impurity amino acid on the chromatographic column; mixing an effluent component subjected to chromatographic separation, a ninhydrin reaction solution and a ninhydrin buffer solution, and carrying out post-column derivatization reaction; and performing optical detection on a product of the derivatization reaction, and performing qualitative and quantitative analysis on main components of the amino acid and impurity amino acid according to a detection signal. According to the method disclosed by the invention, qualitative and quantitative analysis of main target amino acids and one or more impurity amino acids in a sample is synchronously completed in one-time sample injection analysis.

The application relates to a method for realizing ham quality grading based on non-volatile flavor substance analysis, and relates to the field of ham quality grading methods. The application solves the problem that the existing Xuanwei ham fermentation process is not standardized and the fermentation process cannot be adjusted according to the content of non-volatile compounds and the change rule of overall taste. Method: I. Taking naturally fermented mature Xuanwei ham, cutting off the oxidation layer, and quickly separating the biceps femoris and semimembranosus; II. Amino acid determination is carried out on the separated biceps femoris and semimembranosus, and ham quality is graded according to the test data. The application realizes accurate evaluation of Xuanwei ham quality through amino acid analysis. The application is used for Xuanwei ham quality grading.

The invention discloses a fresh peanut nanometer preservation method based on ginger source carbon dots, and belongs to the technical field of food preservation. According to the invention, fresh peanuts are taken as a research object, and the nano structure and surface functional group characteristics of GCDs are confirmed through system characterization, so that the influence of GCDs treatment on the color, texture, macroscopic nutritional ingredients (fat, protein and carbohydrates) and antioxidant enzyme system activity during the storage period of peanuts is deeply explored. More importantly, amino acid analysis and proteomics are creatively integrated, and the action mechanism of the GCDs for maintaining the peanut quality by inhibiting protein oxidative degradation and regulating amino acid metabolic pathways is clarified from the two dimensions of nutrient component retention and molecular mechanism. The invention not only provides a solid theoretical basis for the GCDs as an efficient nano preservative, but also opens up a new thought for deep application of the carbon-based material in the preservation of harvested agricultural products.

The invention discloses an application of chiral amine in chiral amino acid analysis and / or resolution and a method for analyzing and / or resolving chiral amino acid, the method for analyzing and / or resolving chiral amino acid by adopting chiral amine comprises the following steps: reacting one or two of chiral amine d5-APPM and APPM as a labeling reagent with chiral amino acid to obtain a derivative; and then detecting the derivative by using LC-MS (liquid chromatography-mass spectrometry). Wherein the configuration of a carbon atom connected with an amino group on a pyrrole ring in the chiral amine structural formula is an R configuration. The APPM and the deuterated stable isotope form d5-APPM can be subjected to a specific condensation reaction with chiral amino acid, and the generated derivative contains a group easy to ionize, so that the mass spectrum signal response is enhanced in an electrospray ionization (ESI) positive ion mode, and the detection sensitivity is improved; the invention also realizes efficient separation of the chiral amino acid enantiomer on a conventional chromatographic column.

The application discloses a kind of N Hydroxysuccinimide ester and its preparation method and application in amino acid analysis, N Hydroxysuccinimide ester is DPMB or DPEB. The DPMB and DPEB provided by the application can be used for the analysis and detection of amino acids. Through the use of 2,5-dioxopyrrolidin-1-yl-4-(4-methylpiperazin-1-yl)benzoate (DPMB) and its structural analog 2,5-dioxopyrrolidin-1-yl-4-(4-ethylpiperazin-1-yl)benzoate (DPEB) alone or in combination as a pair of structural analog reagents, a substitution reaction occurs with amino acids, and the resulting derivatives can improve the hydrophobicity of amino acids and introduce easily ionizable groups, greatly improving the mass spectrometry response in ESI positive ion mode.