60results about How to "High theoretical plate number" patented technology

The invention discloses a method for preparing surface mesoporous silica core-shell microspheres. The method comprises: selecting monodisperse non-porous silica microspheres with the particle size of 1 to 3 microns, dispersing quaternary ammonium salt B and quaternary ammonium salt A dispersing agents in ethanol water, dispersing the silica microspheres in water, adding a mixed surface active agent solution, regulating a pH value to be 7.5 to 10 by using ammonia water, adding tetraethoxysilane and/or tetramethoxysilane solution, washing, drying, calcining and removing a structure-directing agent, thereby obtaining the surface mesoporous silica core-shell microspheres. By utilizing the quaternary ammonium salt with two different carbon chain lengths as co-structure-directing agent, the core-shell microspheres with a relatively larger radioactive mesoporous structure are prepared; by regulating the proportion of two quaternary ammonium salt structure-directing agents, the mesoporous aperture is controllable in a range of 4 to 20 nm, the obtained radioactive mesoporous structure increases effective specific surface areas of the microspheres, and the application of the microspheres in adsorption, catalysis and separation analysis is improved.

The invention belongs to the field of pharmaceutical analysis and specifically relates to a method for detecting impurity phenylhydrazine in edaravone. The invention aims to provide a conveniently operated, quick and accurate method for detecting the phenylhydrazine. The method comprises the following steps of: controlling a key HPLC (High Performance Liquid Chromatography) detecting condition by adopting liquid chromatogram detection, wherein for a moving phase, a volume percent of acetate buffer solution to carbinol is (70%-90%):(10%-30%) or the volume percent of acetate buffer solution to acetonitrile is (70%-90%):(10%-30%); the concentration of the acetate buffer solution is 0.04-0.06mol/L and pH value is 6.4-6.8; the detection wavelength is 226-238nm; the flow speed is 0.6-1.2ml/min; and the column temperature is 10-35 DEG C. The key detection parameters are controlled, so that the convenient, quick and accurate detecting purpose is achieved. The method provided by the invention has the advantages of convenience for operation accuracy and reliability in detecting result, stronger specificity, and shorter detection time because the main peak retention time is 9 minutes, and provides a brand new choice for detecting the impurity and controlling the product quality.

The invention relates to a method for measuring content of 5-fluorouracil in plasma and colorectal cancer cells based on high performance liquid chromatography and belongs to the technical field of liquid chromatography medical analysis. 5-fluorouracil (5-Fu) is a miazines antineoplastic drug widely applied clinically at present; the antineoplastic chemotherapy effect of 5-Fu is related to the concentration of 5-Fu in the cancer cells; other side effects are caused when the drug concentration in the body is ultrahigh. For the purpose of enhancing the drug therapeutic effect and reducing the side effects, the trend of the concentration of 5-Fu in the cancer cells and the drug concentration in human body shall be strictly monitored. The monitoring has significant clinical significance in promotion of drug therapeutic effect, reduction of toxicity and prevention of post-operation transfer. According to the method provided by the invention, 5-Fu in plasma and colorectal cancer cells is extracted in the manner of solid phase extraction, so that the extraction efficiency is increased; the chromatographic condition is optimized; the peak pattern is improved by adding a trifluoroacetic acid and methyl alcohol system into a detected flow phase; the number of theoretical plates is increased and the chromatographic condition is mild; under a selected optimal chromatographic condition, the measurement for 5-Fu is more precise and accurate than the measurement in literature reports.

The invention discloses a high performance liquid chromatography (HPLC) detection method of Rivaroxaban. The method comprises the following steps: a. preparing a test solution; b. preparing a reference solution; c. respectively detecting the test solution and the reference solution by adopting HPLC, wherein the detection conditions are as follow: the stationary phase of a chromatographic column is silica gel which is coated with amylose-tri ((S)-alpha-methyl phenyl carbamate) on the surface, the mobile phase of the chromatographic column is acetonitrile-water, the flow velocity is 0.5-1.5ml/ min, the column temperature is 10-40 DEG C, and the detection wave length is 200nm-300nm. After the detection method is used, the degree of separation of Rivaroxaban and Rivaroxaban R isomer is more than 3.0, and more theoretical plates are available, so that the detection result accuracy is effectively prevented from being influenced by the interference of all components; furthermore, the detection method has the advantages of being accurate and reliable in detection results, short in analysis time, low in cost, simple and convenient in operation, etc.

The invention discloses a method for detecting reduced glutathione in yeast cells and yeast extracts. A high performance liquid chromatograph is used, and the reduced glutathione is qualitatively and quantitatively detected by an external standard method. The method adopts a methanol/water binary mobile phase (wherein sodium heptanesulfonate, potassium dihydrogen phosphate and phosphoric acid are added in the aqueous phase), the retention time of the reduced glutathione on a chromatographic column is regulated through adjustment of the pH value of a solution or adjustment of the ratio of two phases or cooperative adjustment, the number of theoretical tower plates is increased, the chromatographic peak type is improved, and detection of the content of the reduced glutathione in yeast is accurate and reliable. The method has the advantages of simple operation and high efficiency, provides a good reference for control of detection of glutathione in a process of yeast cell fermentation production of glutathione, and provides a method basis for increasing the quality standard of glutathione raw material.

The invention discloses continuous countercurrent supercritical fluid extraction equipment applied to a plurality of materials and a continuous countercurrent supercritical fluid extraction method applied to the plurality of materials, which aim to solve the problems of high equipment cost and inconvenience of operation and maintenance caused by the excessive height of an extraction tower. A pressurizing pump is communicated with the bottom of the extraction tower by a pipeline. A raw material pump is communicated with a feeding pipeline and a feeding valve, and is communicated with the upper part of the extraction tower by the pipeline. A material outlet at the top of the tower is communicated with a separator by the pipeline. The bottom end of the extraction tower is divided into two parallel pipelines which are provided with a discharge valve and a raw material circulating valve respectively. The pipeline with the raw material circulating valve is communicated with the intake end of the raw material pump. Materials to be extracted flow through the extraction tower from the top down, and are discharged from the bottom of the extraction tower and pumped into the extraction tower again by the raw material pump for cyclic extraction, and the extracted raw materials are discharged from a discharge pipeline at the bottom of the extraction tower. The raw materials are cyclically extracted for twice or more than twice, so the number of theoretical plates of the conventional extraction tower is multiplied, and the height of the extraction tower is greatly reduced.

The invention belongs to the technical field of analysis, and particularly provides a method for detecting the content of A40926 and related substances, adopting a chromatographic column using octyl or octadecyl silane bonded silica gel as a filler, and ammonium dihydrogen phosphate-acetonitrile solution as a mobile phase. By using the method, the content of main component B0 in the A40926 can beaccurately detected, and related substances in the A40926 can be accurately separately detected. The simple, convenient and efficient detection method is provided for quality control in the A40926 production process. The high-performance liquid chromatography has the advantages of good sensitivity, high accuracy, strong data reproducibility and good durability.

The invention discloses a High Perfomance Liquid Chromatography (HPLC) detection method of nisin, the flowing phase contains acetonitrile and water, the initial concentration of the acetonitrile is 5-25 vol.% while the final concentration thereof is 35-100 vol.%.

The invention discloses a flow-dividing baffle for a homogenate tank for filling a chromatographic column, and relates to the technical field of chromatographic column filling by a high-pressure homogenate method. The flow-dividing baffle comprises a first stainless steel metal sheet, stainless steel beads, a second stainless steel metal sheet and a polymer material, wherein the stainless steel beads are arranged between the first stainless steel metal sheet and the second stainless steel metal sheet; the first stainless steel metal sheet, the stainless steel beads and the second stainless steel metal sheet are embedded into the polymer material through the injection molding technology; the flow-dividing baffle wholly adopts a cylindrical cap-shaped structure; the cylindrical cap-shaped structure can sleeve the top end of a cavity of the homogenate tank to realize a sealing effect on the homogenate tank while flow dividing. The flow-dividing baffle is simple in design, convenient to operate and easy to process, can efficiently prevent a pressurized medium from direct impact on a slurry inside the homogenate tank from an inlet, a condition that sparse homogenate generates violent turbulence in a filling process can be avoided, and the column efficiency of the chromatographic column filled through the homogenate method is greatly improved.

The invention provides a method for determining other amino acids in an L-valine raw material by high performance liquid chromatography. The method comprises the following steps of preparing L-valine,leucine, isoleucine, glycine, alanine and phenylalanine reference substance solutions; detecting through a high performance liquid chromatograph, comparing the appearance time and peak shape of L-valine, leucine, isoleucine, glycine, alanine and phenylalanine in a chromatogram of the test sample with those of L-valine, leucine, isoleucine, glycine, alanine and phenylalanine in a chromatogram of the reference substance solution, and judging whether the test sample solution contains other amino acids or not. According to the method, by screening an aminopropyl bonded silica gel chromatographiccolumn, the separation effects are found, and by screening the wavelengths, the maximum absorption of each amino acid is found, and the retention time of each amino acid peak on the chromatographic column is regulated and controlled by regulating the ratio of triethylamine, the pH value and the ratio of two phases by utilizing an acetonitrile/phosphate buffer solution binary mobile phase, so thatthe hydrolysis and shedding of bonded aminopropyl in the amino column are effectively prevented, and the problems of short reverse-phase service life and unstable baseline of the amino column are solved.

The invention provides a method for detecting fasudil hydrochloride and nine related substances of the fasudil hydrochloride. The method comprises the following steps that a system suitability solution, a test solution and a reference solution are prepared, the solutions are injected into a high performance liquid chromatograph for detection, and the content of fasudil hydrochloride and the related substances of fasudil hydrochloride is calculated according to an external standard method; the method is characterized in that the detection conditions comprises the following conditions that a chromatographic column is an alkyl bonded silica gel packed column; a detector is a diode array detector; the detection wavelength is 240-290nm; the column temperature is 20-35 DEG C; the injection volume is 10-100[mu]l; the flow rate is 0.5-2.0ml/min; a mobile phase is buffer salt-organic phase, and pH of the buffer salt is adjusted to 3-5; and a elution method is gradient elution. The method has the following technical effects that the detection method can detect fasudil hydrochloride and nine related substances, the separation degree between fasudil hydrochloride and the related substances meets the requirements (greater than 2.0), and the number of theoretical plates is high and the tailing factor is good.

The invention provides a method for determining the content of clindamycin phosphate vaginal tablets. The method adopts high performance liquid chromatography for detection, selects mobile phase components, adopts scientific proportioning, adopts gradient elution and sets elution conditions, and can rapidly and accurately detect the content of clindamycin hydrochloride for injection so as to achieve the purpose of simply, conveniently, rapidly and accurately controlling the product quality.

The invention discloses a method for measuring chromatographic purity of difluprednate. The method comprises the following steps: 1, preparation: chromatographic conditions: an ultraviolet visible light detector and an ultimate XB-C18 chromatographic column are adopted, the detection wavelength is 240 nm, the column temperature is 35 DEG C, the flow velocity is 0.9 ml/min, the flowing phase is that the methanol/water ratio is 68:32, and the sampling quantity is 15 [mu]L; preparation of a sample-for-test liquid: taking a proper amount of difluprednate, and adding a flowing phase to prepare a solution of 5 mg/ml to serve as the sample-for-test solution; step 2, purity measurement: injecting the sample-for-test solution into a chromatographic instrument, recording a chromatogram till twice retention time of a difluprednate main peak is reached, adjusting a proper instrument integral parameter and calculating by using an area normalization method to obtain the chromatographic purity. Compared with the prior art, the method for measuring the chromatographic purity of the difluprednate has the advantages of being simple and accurate, high in sensitivity and capable of effectively detecting the purity of the difluprednate.

The invention provides a method for detecting the purity of 1-amino-2-propanol and related substances. The method is used for detecting the purity of 1-amino-2-propanol and the content of an isomer (2-amino-1-propanol). The purity of 1-amino-2-propanol and the related substances are qualitatively and/or quantitatively detected through a gas chromatography method, the known impurity (2-amino-1-propanol) is calculated through a standard curve method, other unknown impurities are calculated through an area normalization method, the total impurities are equal to the sum of the content of all the known impurities and the content of all the unknown individual impurities, and the purity of 1-amino-2-propanol is calculated through the difference of 100% and the total impurity content. The purity of 1-amino-2-propanol and the isomer impurity (2-amino-1-propanol) are detected.

The invention belongs to the technical field of chemical analysis and relates to ananalysis method for the content of 5-chloro-2-methoxycarbonyl-1-indanone ester. According to the analysis method, high performance liquid chromatography is adopted to detect the content of the 5-chloro-2-methoxycarbonyl-1-indanone ester; an SBC8 reversed phase chromatographic column is adopted as a chromatographic column; the temperature of the chromatographic column is 30 DEG C to 50 DEG C; a mobile phase is a mixed system of acetonitrile and ammonium carboxylate; the detection wavelength is 230 nm and 270 nm;impurities, a main peak and a solvent peak can be completely separated; the chromatographic peak shape is good; the retention time is stable; the integral calculation result is accurate; the repeatability is good; the reliability of the obtained result is high; and the method is particularly suitable for quality control of pesticide raw drug intermediate products.