14 results about "Theoretical plate" patented technology

The invention relates to an overlapped chromatographic peak positioning and splitting method and system based on a numerical stable function. The method comprises the following steps: de-noising chromatographic data and correcting a baseline; calculating a second derivative by using SG filtering, grouping continuous points according to a negative threshold value, and determining an initial position of each peak by using a second-order minimum value; establishing a peak function of bidirectional exponential correction by taking a peak position as an initial value, setting parameters and boundaries such as area, center, width, trailing and the like, constructing a residual error minimization target, and performing robust fitting by adopting a trust region reflection algorithm; and indexes such as suitability, output peak area, center, broadening, separation degree, theoretical plate number and the like are verified by residual errors. According to the method, valley point or prior component information is not needed, the method is insensitive to noise and baseline drift, serious overlapping and trailing / leading edge peaks of multiple components can be effectively processed, convergence is high, the method is insensitive to initial values, parameters can be expanded to different peak shapes, and the method is suitable for qualitative and quantitative analysis of automatic and high-flux chromatographic data.

The invention discloses a detection method for simultaneous determination of lidocaine and prilocaine content in a lidocaine emulsifiable paste by high performance liquid chromatography, which comprises the following specific steps: step 1, taking lidocaine and prilocaine reference substances, and preparing a reference substance solution to detect the separation degree and theoretical plate number between lidocaine and prilocaine; step 2, taking the riptacaine cream, diluting with a solvent, and preparing a test solution; and step 3, acquiring chromatograms of the test solution and the reference solution under proper chromatographic separation conditions by applying high performance liquid chromatography and adopting a reversed-phase liquid chromatographic column, and quantitatively determining the content of lidocaine and prilocaine by an external standard method. The method overcomes the defects of complicated operation, poor durability, long detection time and poor specificity in the prior art, and has the characteristics of simplicity and easiness in operation, short running time, high detection efficiency, strong durability, strong specificity, good precision and high accuracy.

The invention discloses a method for detecting a zoledronic acid residual solvent. The method comprises the following steps: (1) respectively preparing a blank solution, a reference solution and a test solution; (2) sample injection detection; an instrument is a gas chromatograph with a hydrogen flame ionization detector, nitrogen is used as carrier gas, and the carrier gas is injected into the gas chromatograph by adopting headspace sample injection; and respectively carrying out sample injection detection to obtain a chromatogram of the reference substance solution and a chromatogram of the test solution, and carrying out detection analysis by adopting an external standard method to complete the determination of the zoledronic acid residual solvent. According to the method, the gas chromatograph is adopted to detect the residues of methanol, tetrahydrofuran, isopropanol and triethylamine in zoledronic acid, the detection chromatographic conditions are optimized in a targeted manner, and under the condition of ensuring good theoretical plate and separation degree, a plurality of residual solvents are placed in the same system for detection, so that the detection efficiency is greatly improved; and meanwhile, the detection chromatographic conditions are specifically optimized, so that the organic solvents are completely separated, and the linear relation is good in the investigated range.

The invention relates to the technical field of chemical analysis, and discloses a liquid chromatography separation and detection method for impurities in 2, 5-furandicarboxylic acid, which comprises the following steps: detecting a 2, 5-furandicarboxylic acid sample by liquid chromatography: adopting a chromatographic column of pentafluorophenyl bonded silica gel filler; a mobile phase A and a mobile phase B are adopted as a mixed mobile phase for elution, the mobile phase A is a trifluoroacetic acid aqueous solution, and the mobile phase B is methanol; wherein when isocratic elution is adopted, the number of theoretical plates of a chromatographic column is greater than 46000; when gradient elution is adopted, the number of theoretical plates of the chromatographic column is greater than 37000. According to the present invention, the FDCA and the plurality of impurities in the sample can be separated and quantitatively determined at one time, the condition that the impurity peaks are completely or partially covered due to the overhigh FDCA content is avoided, the problem that the impurity peaks are severely overlapped and cannot be quantitatively determined is also avoided, the analysis precision is high, and the method is simple, rapid and effective.

The invention relates to the technical field of medicine quality control and separation detection, in particular to a flumazenil injection related substance detection method and application thereof. Taking the test solution and the contrast solution, and carrying out quantitative detection on the impurity A, the impurity B, the impurity D, the impurity E and the impurity F by adopting a liquid chromatography self-contrast method; the chromatographic conditions are as follows: a phenyl-hexyl mixed bonded phase chromatographic column is adopted, the column temperature is 15 DEG C, and the number of theoretical plates is gt; 15000, 15000; the mobile phase is acetonitrile and diammonium hydrogen phosphate (0.02 M, pH 4.8), the gradient elution is carried out for 0-10 minutes, and the acetonitrile accounts for 5%-25%; 25% of acetonitrile is used for 10-35 min; the detection wavelength is 230nm. In order to eliminate co-elution interference, a dual-wavelength combined detection technology is adopted, and interference of impurity peaks on main peaks is further eliminated. The methodology verifies that the detection method can be used for detecting related substances in flumazenil injection and bulk drugs.

A method for extracting artemisinin, relating to the field of artemisinin extraction technology, includes the steps of extraction, enhanced extraction, separation, concentration, and purification. The purification employs an innovative column chromatography method, specifically a column height-to-diameter ratio of 1.2:1; adding hexane and diethyl ether eluent at a volume ratio of 8:2, with the added packing material height being 1.20-1.25 times the column diameter; and obtaining artemisinin after column chromatography. Alternatively, the innovative recrystallization method involves dissolving a paste in a crystallization vessel containing 50°C hot methanol, then lowering the temperature to 9-11°C, while locally heating and maintaining the temperature at the bottom of the crystallization vessel during cooling. Solid crystallization occurs under a uniform temperature distribution within the vessel, followed by filtration. This process is repeated twice to obtain artemisinin. The beneficial effects include an increased theoretical plate number of the chromatography column, significantly improved separation efficiency, and a significantly higher purity of artemisinin; the uniform temperature distribution within the crystallization vessel effectively improves the purity of the crystals.

In the specification, a method for purifying a compound by column chromatography, and a method for optimizing the symmetry factor and theoretical plate number by allowing the slurry to settle and reducing the sedimentation volume of the slurry. A compound purified by such method is also provided.

The invention provides a determination method for analyzing the fingerprint spectrum of Huoxiang Zhengqi soft capsules, and controls the quality of the Huoxiang Zhengqi soft capsules. The method comprises the following steps: a chromatographic condition and a system suitability test, wherein octadecylsilane bonded silica gel is used as a filler; acetonitrile is used as a mobile phase A, 0.1% phosphoric acid is used as a mobile phase B, and gradient elution is performed (the chromatographic conditions are 0-15 min, 10%→47% A, 15-20 min, 47% A, 20-30 min, 47%→60% A, 30-40 min, 60% A); the detection wavelength is 283 nm for 0-12 min and 254 nm for 12-50 min; and the column temperature is 30 DEG C. The number of theoretical plates calculated based on the imperatorin peak should be no less than 5000; preparation of reference solution; preparation of test solution; finally, determination by the assay method and extraction with methanol to ensure the stability and accuracy of the ingredients in Huoxiang Zhengqi soft capsules, and HPLC method is used to establish the fingerprint of Huoxiang Zhengqi soft capsules, which can reflect its overall chemical characteristics. The method is simple and fast, and provides a scientific basis for comprehensively improving its quality.

The invention discloses a method for detecting the content of grapipiron. The invention adopts a reverse phase high performance liquid chromatograph to measure the standard product and the test product of grapipiron, and obtains the content of the sample to be tested according to the standard curve. The method can accurately measure the content of grapipiron, and the detection method without interference is reliable and stable, with high sensitivity and high theoretical plate number. At the same time, the operation is relatively simple, and the content of grapipiron can be effectively measured, which is conducive to ensuring the quality of grapipiron raw materials and preparations.

The invention provides a method for separating 1-butene in mixed C4, which is characterized in that a dividing wall column in an upper dividing wall form is used for separation, the area ratio of a feeding side to a product extraction side is (1: 9)-(9: 1), a mixed C4 fraction enters the dividing wall column from the middle of the feeding side, the number of theoretical plates of the dividing wall column is 40-200, the operating pressure is 0.1-2Mpa, the tower top temperature is 20-120 DEG C, the tower bottom temperature is 30-200 DEG C, and the 1-butene in the mixed C4 fraction is separated from the dividing wall column. C4 light components are extracted from the tower top of the feeding side, 1-butene-rich components are extracted from the tower top of the product extraction side, part of the 1-butene-rich components are condensed and refluxed, part of the 1-butene-rich components is discharged out of the device, part of the 1-butene-rich components is refluxed to the product extraction side through the tower top, a tower kettle product is heavy C4 components, part of the heavy C4 components is discharged out of the device, and part of the heavy C4 components is refluxed to the dividing wall tower from the tower kettle through the reboiler. The method is short in process flow and high in efficiency, and the obtained 1-butene is high in purity.

The invention provides a method for detecting the dissolution rate of domperidone tablets, and relates to the technical field of analytical chemistry. According to the method, high performance liquid chromatography is adopted for determination, mobile phases comprise a mobile phase A and a mobile phase B, the mobile phase A is methanol-ionic liquid, the mobile phase B is an acetonitrile-glacial acetic acid solution, a gradient elution procedure is adopted, effective separation of domperidone and a large number of other auxiliary materials and impurities is achieved, the number of main peak theoretical plates of domperidone is larger than 3000, and the detection wavelength is 250nm. The domperidone component is exclusively and precisely measured, the quality evaluation of the dissolution rate of the domperidone tablet is greatly improved, and the detection method has high specificity and high sensitivity, and meanwhile, meets the green and environment-friendly requirements.

Methods and devices are disclosed for a separation device including a sintered polymeric monolith having polymeric microparticulate solids with a pore size from about 0.5 to about 8 microns, a porosity between about 50 percent to about 80 percent and a chromatographic uniformity characterized by an HETP (height equivalent of a theoretical plate) less than about 100 microns.

Methods and devices are disclosed for a separation device including a sintered polymeric monolith having polymeric microparticulate solids with a pore size from about 0.5 to about 8 microns, a porosity between about 50 percent to about 80 percent and a chromatographic uniformity characterized by an HETP (height equivalent of a theoretical plate) less than about 100 microns.

The invention belongs to the technical field of medicine detection, and discloses a detection method of doogliptin related substances, which comprises the following steps: mixing a monopotassium phosphate solution and acetonitrile to prepare a blank solution; the method comprises the following steps: mixing impurities of dogliptin with dogliptin to obtain a test sample; then carrying out solution and quantitative dilution on the test sample by using the blank solution as a diluent to prepare a standard test sample solution; detecting the labeled test sample solution by adopting a high performance liquid chromatography, wherein a mobile phase comprises an A-phase monopotassium phosphate solution and a B-phase acetonitrile. According to the present invention, the high performance liquid chromatography is adopted, the potassium dihydrogen phosphate and the acetonitrile are adopted as the diluents, the potassium dihydrogen phosphate-acetonitrile is adopted as the mobile phase system, and each chromatographic condition is optimized, such that the obtained chromatogram has characteristics of good peak pattern, specifically, the peak pattern of the main peak and each impurity peak is narrow, sharp, good in symmetry, high in theoretical plate number, and the like; and the sample injection precision is high, and the repeatability is good.