19 results about "Reversed-phase chromatography" patented technology

The application discloses a lipoic acid high-performance liquid chromatography detection method, which comprises the following steps: S1, sample pretreatment: ultrasonic extraction is carried out on the sample by using a composite extraction liquid, then solid-liquid separation is carried out, and a test sample solution is obtained; the composite extraction liquid is an acetonitrile water mixed solution containing cysteine and EDTA salt; S2, HPLC detection: the chromatographic conditions are as follows: a C18 reversed-phase chromatographic column is used, a buffer solution-alcohol mixed system is used as a mobile phase, the pH of the buffer solution is 2.5-3.5, the detection wavelength is 210-220 nm in the first stage and is 275-285 nm in the second stage, the first stage is 0-7-9 min, and the second stage is 7-9 min-14-16 min. By optimizing the pretreatment method, optimizing the chromatographic conditions and adopting a dynamic detection wavelength, the lipoic acid content detection method with high sensitivity and strong anti-interference ability is obtained.

This invention discloses a purification method for Tirzepatide. The method includes: dissolving crude Tirzepatide peptide in ammonia or sodium bicarbonate solution, filtering, and purifying by reversed-phase chromatography to obtain a purified sample; eluting the purified sample using reversed-phase high-performance liquid chromatography (RP-HPLC) with a sodium or potassium buffer solution as mobile phase A3 and one or a mixture of acetonitrile, methanol, and isopropanol in any proportion as mobile phase B, preparing a sodium or potassium salt fraction; cooling the sodium or potassium salt fraction to -20 to 10°C and maintaining the temperature; then adding an organic solvent to the fraction, controlling the temperature at -20 to 10°C to precipitate the sample; after complete precipitation, solid-liquid separation is performed, the solid is collected, dissolved in water, filtered, and freeze-dried. This invention improves the concentration speed, ensures product purity, and strictly controls impurities.

The application provides a method for determining the content of biotin in a complex vitamin preparation. The method comprises detecting the content of biotin by high performance liquid chromatography, wherein a surface porous reversed-phase chromatographic column with modified amide groups is used for gradient elution, and a mobile phase A and a mobile phase B are used, the mobile phase A comprises potassium dihydrogen phosphate buffer and acetonitrile, and the mobile phase B comprises acetonitrile. The method can realize the non-interference separation and detection of the content of biotin in the complex vitamin preparation with a complex matrix, and has the advantages of simplicity, good specificity, rapid analysis, accurate result and sensitive response.

The present application belongs to the field of biopharmaceuticals. Disclosed is the use of a stem cell extract in the preparation of a drug for treating or preventing arthritis by regulating lysosomal and / or mitochondrial functions, wherein a method for preparing the stem cell extract comprises: S1) culturing mesenchymal stem cells and creating stress conditions to stimulate the mesenchymal stem cells; and S2) isolating and purifying a culture supernatant of the mesenchymal stem cells cultured in S1) to obtain a stem cell extract, wherein S2) comprises: S21) filtering the culture supernatant to obtain a filtrate; S22) concentrating the filtrate by means of 3KD ultrafiltration to obtain a crude sample; S23) purifying the crude sample by means of size-exclusion chromatography or reversed-phase chromatography to prepare a purified sample; and S24) preparing the purified sample into a preparation. In the present application, the culture supernatant containing secretions of the stressed stem cells is obtained by means of stress culturing of the stem cells, and in combination with a purification method, the supernatant is prepared into a preparation which can be used for treating arthritis.

The application relates to the technical field of medicines, and discloses application of a traditional Chinese medicine composition in serum neurotransmitters, which comprises the following steps: selecting 6-8-week-old mice to establish normal models, chronic fatigue syndrome models and functional dyspepsia models; blood sampling is conducted on the mice of the normal models, the chronic fatigue syndrome models and the functional dyspepsia models to obtain normal blood samples, CFS blood samples and FD blood samples respectively; protein precipitation operation is conducted to obtain normal deproteinized supernatants, CFS deproteinized supernatants and FD deproteinized supernatants; separation is conducted by using a reversed-phase chromatographic column, and then mass spectrometry is conducted to obtain normal serum neurotransmitter mass spectra, CFS serum neurotransmitter mass spectra and FD serum neurotransmitter mass spectra respectively; concentration value calculation and rhythm fluctuation analysis are conducted to obtain a neurotransmitter function index and rhythm stability quantitative score respectively. Therefore, the mechanism of the traditional Chinese medicine composition in serum neurotransmitters is clearly quantitatively characterized.

The application discloses a method for simultaneously detecting retinoids and lipid-soluble vitamin metabolic marker groups in biological samples and matching reagents. The application is based on magnetic bead solid-phase extraction technology, significantly improves sample purification effect, and reduces matrix interference; in combination with a high-aqueous-phase reversed-phase chromatography system and a positive-negative ion switching multi-reaction monitoring mode, simultaneous separation and detection of seven retinoid molecules and a full spectrum of lipid-soluble vitamins are realized. The method has high sensitivity, strong specificity and wide detection range, and for the first time realizes one-stop analysis across species and sample types, thereby providing reliable platform support for clinical and scientific research applications.

The present application belongs to the field of fingerprint, and particularly relates to a method for detecting medicinal stems of Dendrobium candidum from Sichuan origin. The specific technical scheme is as follows: a method for constructing a Dendrobium fingerprint, comprising the following steps: mixing a Dendrobium powder to be tested with methanol, performing ultrasonic treatment, taking out, cooling, and filtering; evaporating the filtrate under reduced pressure, dissolving the residue with methanol, filtering, shaking, and obtaining a test solution; taking the test solution, performing high performance liquid chromatography detection, and recording a fingerprint; and the chromatography detection has the following chromatography conditions: a C 18 reverse-phase chromatography column; a column temperature of 30 DEG C; a detection wavelength of 270 nm; and a total flow rate of 0.8 mL / min. The method provided by the present application is simple to operate, has complete characteristic components, and has a stable test solution, high precision, and good reproducibility.

This invention belongs to the field of chromatographic detection and analysis, and discloses a reversed-phase chromatographic analysis method for the purity of enterokinase protein. High-performance liquid chromatography (HPLC) is used to detect enterokinase in the sample solution. In this HPLC method, the chromatographic column is selected from reversed-phase chromatographic packing material C18 or C8, with a particle size of 3.5~5 μm and a pore size of 120~1000 Å. The mobile phase is selected as follows: an aqueous solution of heptafluorobutyric acid (HFA) is used as mobile phase A, and an acetonitrile solution of HFA is used as mobile phase B. This invention improves the separation of the main peak and subsequent impurities in the enterokinase stock solution by screening suitable mobile phase systems and column types. It also optimizes chromatographic parameters such as the proportion of modifier in the mobile phase, column temperature, sample loading, mobile phase gradient, and wavelength, ultimately achieving effective separation of the main peak and subsequent impurities in the enterokinase stock solution. Furthermore, the analysis time is short and the repeatability is good, providing an effective analytical method for the quality control of enterokinase stock solution.

The present application relates to a kind of quantitative determination electronic cigarette liquid trimellitic acid, p-phthalic acid, m-phthalic acid method, belong to electronic cigarette liquid component detection technical field, it is characterized in that: using to electronic cigarette liquid sample adds certain concentration of formic acid aqueous solution extraction and improves the acid-base environment of sample, further purify sample by vortex, filtration, using core-shell (surface porous) reversed-phase chromatographic column, realize the complete separation of three target objects, combined with liquid chromatography mass spectrometer technology, internal standard method quantitative, realize the accurate detection of trimellitic acid, p-phthalic acid, m-phthalic acid in electronic cigarette liquid.The present application has the advantages that simple operation, quantitative accurate, high sensitivity, target can be extracted from complex electronic cigarette liquid matrix and accurately quantified, can satisfy the accurate detection of trimellitic acid, p-phthalic acid, m-phthalic acid in electronic cigarette liquid.

This invention discloses a method for detecting L-5-methyltetrahydrofolate content with magnesium ion interference resistance, comprising the following steps: S1. Sample pretreatment: S11. Using phosphate buffer containing antioxidants, disodium EDTA, and sodium citrate as the extraction reagent, the sample is ultrasonically extracted in an ice-water bath at 2-6°C under light-protected conditions; S12. Extraction is performed using an aqueous two-phase extraction system; S2. HPLC detection: A reversed-phase chromatographic column is used, with gradient elution using mobile phase A and mobile phase B; mobile phase A is an aqueous solution of potassium dihydrogen phosphate containing antioxidants, sodium citrate, and disodium EDTA, and mobile phase B is methanol. This invention solves the problems of peak tailing, signal suppression, and matrix interference in the detection of L-5-methyltetrahydrofolate in complex magnesium-containing systems by synergistically dissociating the magnesium-folate complex through pH control and a composite masking agent, combined with aqueous two-phase extraction to purify the matrix, and optimized HPLC separation conditions.

The present invention relates to a polysorbate separation method, comprising a polysorbate-containing solution to be measured flowing through a mixed-mode chromatograph and a reversed-phase chromatograph which are coupled in series, the use of the separation method in measuring the polysorbate content of said polysorbate-containing solution, a related apparatus, and a method for measuring the polysorbate content by using the separation method.

The present invention relates to a method for analyzing a sample, the method comprising: (a) incubating a sample comprising an analyte with at least one enzyme to produce a digestion mixture comprising fragments of the analyte; (b) loading the digestion mixture onto a reversed-phase chromatography column; and (c) performing reversed-phase chromatography on the digestion mixture, wherein the at least one enzyme is hydrophobically modified to increase a retention time of the at least one enzyme such that the at least one enzyme elutes from the reversed-phase chromatography column later than the fragments of the analyte.

This invention discloses a method for the quantitative analysis and detection of 19 branched-chain fatty acid ester isomers of four classes of hydroxy fatty acids in the field of biomedical quantitative detection technology. The method involves preparing single-standard stock solutions of 19 hydroxy fatty acid branched-chain fatty acid ester reference standards, mixing the stock solutions and diluting them stepwise to prepare mixed reference standard solutions with ≥5 concentration levels. Then, using ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS / MS), the hydroxy fatty acid branched-chain fatty acid esters in the mixed reference standard solutions are separated by reversed-phase chromatography. Mass spectrometry employs electrospray ionization mode and multiple reaction monitoring (MRM) to monitor the characteristic ion pairs of each hydroxy fatty acid branched-chain fatty acid ester. A standard curve is plotted using peak area versus concentration, and the content is calculated. This method achieves, for the first time, simultaneous, highly specific, and highly sensitive quantitative analysis of 19 isomers of four classes of FAHFAs, providing a tool for exploring the biological functions of FAHFAs and related biomarkers.

The application discloses a method for separating chiral isomers in siRNA molecules and relates to the technical field of oligonucleotide separation analysis. The siRNA to be separated is loaded on a reversed-phase liquid chromatography column for reversed-phase chromatography, the reversed-phase liquid chromatography column is a C18 chromatography column, the column temperature is 80-90 DEG C, the mobile phase A is 20-30 mM ammonium acetate aqueous solution, the mobile phase B is a 20-30 mM ammonium acetate water-acetonitrile solution mixed system, and the linear promotion rate of the mobile phase B is 0.06% mobile phase B / min-0.08% mobile phase B / min. The application can simultaneously realize high-efficiency separation of chiral isomers of siRNA antisense chains and sense chains, and has excellent precision.

This invention discloses a two-dimensional liquid chromatography (HPLC) method for determining lactoferrin in infant formula. Based on online purification HPLC technology, the first dimension uses a heparin affinity column, and the second dimension uses a reversed-phase C4 column. This method achieves accurate qualitative and quantitative analysis of lactoferrin in infant formula. By adding Tween-20 and sodium chloride to the extract, non-specific adsorption and competitive binding in complex matrices are effectively inhibited, significantly improving the recovery rate of lactoferrin (93.5%–97.3%). The method exhibits good linearity in the range of 5–200 μg / mL, with a detection limit of 2 mg / 100g, a quantitation limit of 5 mg / 100g, and an RSD of 1.2%–3.9%, providing accurate and reliable results. Optimized flow path and cleaning procedures enable online two-dimensional purification and analysis, allowing the expensive heparin affinity column to be reused and reducing detection costs.

This invention relates to the field of detection and analysis technology, and discloses a method for detecting perfluorooctanoic acid (PFOA) in water. The method includes the following steps: filtering a water sample through a filter membrane and collecting the filtrate; using a C18 reversed-phase chromatographic column, with an aqueous solution containing tetrabutylammonium bisulfate as mobile phase A and acetonitrile as mobile phase B, isocratic elution is performed at a detection wavelength of 208-215 nm, and detection is performed using a UV detector or a diode array detector; qualitative analysis is performed based on chromatographic retention time, and quantitative analysis is performed using the external standard method based on chromatographic peak area. This invention, by optimizing the detection wavelength and introducing tetrabutylammonium bisulfate as an ion-pairing reagent, effectively improves the chromatographic peak shape and resolution of PFOA, achieving a correlation coefficient R0 within a wide linear range of 0.5-200 mg / L. 2 The detection limit is >0.999, which meets the detection requirements of most water bodies; the method has good repeatability, with a spiked recovery rate of up to 98.30%-108.35% in complex matrices; it has strong anti-interference ability, and the detection results are stable in the pH range of 4-10, making it suitable for actual water samples under different acid and alkaline conditions.

This invention discloses an HPLC method for determining the ortho-O iron content in EDDHA-Fe chelates, comprising the following steps: S1. Sample pretreatment: S11. The sample is first extracted with an aqueous solution, followed by solid-liquid separation; S12. The liquid phase is purified by passing it through a strong acid cation exchange resin to obtain a purified solution; S13. EDTA salt is added to obtain a test solution; S2. HPLC detection: A C18 reversed-phase column is used, with gradient elution using mobile phase A and mobile phase B; mobile phase A is a 0.05-0.15% (w / w) aqueous solution of phosphoric acid with a pH of 2.5-3.0; mobile phase B is methanol. This invention, through optimized chromatographic conditions and innovative sample pretreatment, establishes a high-resolution, interference-resistant method for O-O detection, solving the problems of insufficient resolution, interference ion influence, and inaccurate quantification in existing methods.

This invention relates to a non-targeted identification method for mycotoxin metabolites in wine based on mass spectrometry coupled with chromatography, specifically for the detection and identification of ochratoxin A and its metabolites in wine. Through sample pretreatment, chromatographic separation, mass spectrometry detection, data screening, and fragment ion confirmation of wine samples, non-targeted detection of ochratoxin A and its metabolites can be achieved without relying on standards. In the sample pretreatment stage, the target analyte is extracted using acidified acetonitrile solution, and impurities are removed by salting out and centrifugation. Separation of ochratoxin A and its metabolites is achieved by coupling high-performance liquid chromatography with time-of-flight mass spectrometry using a reversed-phase C18 column for gradient elution. The mass spectrometry analysis uses full-scan mode and alternates between positive and negative ion modes to ensure high resolution and high sensitivity, making it suitable for the detection of mycotoxins in wine and other foods, meeting food safety regulatory requirements.