31results about How to "Determination does not interfere" patented technology

The invention relates to a detection method for simultaneously measuring OXC in human plasma and metabolite MHD and MHD-G, and belongs to the technical field of biological detection. An experiment is carried out by taking nitrazepam as an internal standard, and can simultaneously detect the plasma concentrations of the three compounds by adopting high performance liquid chromatography-tandem mass spectrometry after pretreatment through precipitation protein. The detection method is short in time, high in specificity and sensitivity, and convenient in operation, and is successfully applied to the analysis and research of oxcarbazepine in the human plasma and the metabolite thereof.

The invention discloses a method for determining the contents of hydrofluoric acid, fluosilicic acid and nitric acid in etching acid through acid-base titration and complexometric titration. The method comprises the following steps: (1) adding potassium salt into a sample to precipitate fluosilicic acid, titrating supernatant by using a sodium hydroxide standard titration solution by taking phenolphthalein as an indicator, and calculating the total acidity of the sample solution; (2) adding potassium salt into the sample to precipitate fluosilicic acid, titrating fluorine ions in the solutionby using a lanthanum nitrate standard titration solution by taking a fluorine ion selective electrode as an indicating electrode, determining a reaction endpoint by using a secondary micro-commerce method, and calculating the content of hydrofluoric acid; (3) heating and hydrolyzing fluosilicic acid, titrating total fluorine in the solution by using a lanthanum nitrate standard titration solutionby taking a fluorine ion selective electrode as an indicating electrode, determining a reaction endpoint by using a secondary micro-commerce method, and calculating the content of fluosilicic acid byusing a subtraction method; and (4) obtaining the nitric acid content by subtracting the sum of the hydrofluoric acid content and the fluosilicic acid content from the total acidity.

The invention discloses a method for measuring concentration of 5,2'-dyhydroxyl,6,7,8,5'-tetramethoxyflavone (skullcapflavone II) in plasma. A liquid chromatography-mass spectrometry system is used for carrying out measuring, a sample to be measured is firstly taken, a certain amount of organic solvent is added for medicine liquid-liquid extraction, after pretreatment, chromatographic column separation is carried out, and a mass spectrometry detector is used for carrying out detection. According to the method, quickness and accuracy are achieved, sensitivity is high, and operation is easy and convenient; the method is suitable for measuring the concentration of skullcapflavone II in the plasma.

The invention relates to a liquid chromatogram-tandem mass spectrum method for detecting pitavastatin in human plasma, and application to clinical pharmacokinetic research. The invention provides a method for detecting pitavastatin concentration of plasma. By the method, the pitavastatin concentration of the plasma can be analyzed through LC-MS / MS. According to the method provided by the invention, a protein precipitate pretreatment method is preferably adopted, deuterated pitavastatin serves as internal standard, Eclipse Plus Phenyl-Hexyl column isocratic elution is adopted, and electrospray ionization (ESI) tandem mass spectrum detection is adopted. By adoption of the method provided by the invention, the extraction and recovery rate of the plasma sample is 93 percent or higher and is not influenced by matrix effect, the stability of the pitavastatin is inspected by counting the pitavastatin concentration RSD% before pretreatment, the accuracy of the measured data is guaranteed, the method is high in specificity and selectivity, high in sensitivity, rapid in detection and small in use amount, and simple, reliable, high-flux and condition-controllable clinical mass-batch sample analysis requirements are met. The specificity, the stability and the like of the method provided by the invention are verified, and the method can be used for evaluating the bioequivalence of various dosage forms of pitavastatin successfully.

The invention discloses a method for measuring the content of pyridine in decitabine impurities. A methyl alcohol-N-methyl-pyrrolidone-triethylamine mixed solution is used as a solvent, and a direct injection gas chromatographic method is adopted for measurement. The problems that decitabine raw material glucoside stability is poor, dissolution is not easily achieved, the recycling rate of an existing detection method is seriously low and interference is likely to be caused by solvent peaks are solved. According to the method, it is tested that a blank solvent has no interference peaks for residual solvent pyridine measurement, the precision is good, the relative standard deviation (RSD) is only 0.46%, the reproducibility is good, the linear relation is good, the average recycling rate is high, and pyridine possibly remaining in glucoside can be accurately and quantitatively detected. Effective quality control is achieved for preparing second-class solvent pyridine in the decitabine raw material glucoside, and the quality of decitabine and drug use safety are ensured at the same time.

The invention discloses a determination method of sodium oleate content in an injection use dry emulsion. The method comprises the steps that an HPLC method is adopted to separate oleic acid and other components, the oleic acid content is determined according to an external standard method, and based on the relation between the oleic acid and molecular weight of sodium oleate, the sodium oleate content in the dry emulsion is calculated. The determination method is sensitive, accurate, exclusive, efficient, convenient and low in cost.

The invention specifically relates to a method for separating and measuring degraded impurities in dutasteride raw materials and preparations by using high performance liquid chromatography, and the impurities are generated under forced degradation conditions. The method of the invention adopts octadecylsilane bonded silica gel as a chromatographic column, and uses mobile phase A and mobile phase B to carry out linear gradient elution. Since there are no quality standards for dutasteride soft capsules in the pharmacopoeias of various countries at present, and there are no relevant documents or standard reports, so this set of HPLC methods is a set of methods completely self-built. The present invention explores the detection wavelength, diluent Conditions such as mass concentration determine a set of methods suitable for the detection of the substance. The method has little interference during detection, has good specificity, good reproducibility and high accuracy, and can play a role in providing technical support for the quality control of dutasteride soft capsules.

The invention belongs to the medical inspection field, relates to an analysis detection method of drug in the body of a person, and specifically relates to the method that the densities of fosphenytoin, phenytoin and 4'-hydroxyl phenytoin which is the main metabolite of fosphenytoin and phenytoin in can be detected at the same time. The method in the invention is characterized in that pilot sample is pretreated; fosphenytoin, phenytoin and 4'-hydroxyl phenytoin are separated with each other in an acidity flowing phase chromatographic column and are detected by UV detector. The method in the invention has the advantages of little sample, easy, swift and sensitive operation and short analysis period; furthermore, the method in the invention doesn't need expensive equipment and reagent, is suitable for clinical conventional detection and can be used to adjust the drug dose, which can guarantee safe and effective prescription and has the important clinical practice significance.

The invention relates to a method for determining concentration of sclareol in blood plasma and belongs to the technical field of biological detection. Nitrazepam is taken as an internal standard, a protein precipitation method is adopted, and the concentration of sclareol in the determined blood plasma is calculated by virtue of blood plasma sample pre-treatment, chromatograph, mass spectrometry and an internal standard method. The method for determining the concentration of sclareol in the blood plasma is rapid, accurate, high in sensitivity and easy to operate, and a methodological foundation is laid for drug metabolism dynamic research of sclareol in an animal body.

The invention provides a standard sample used for headspace analysis of trace quantity benzene in water and a method for measuring trace quantity benzene in water by using the method thereof. The method comprises the following step of dissolving a benzene solution in a polarity sulfone organic solvent with high boiling point and capable of dissolving with water and benzene to obtain the standard sample. When in use, the standard sample is diluted by water to the required concentration; wherein the mass ratio of benzene to polarity sulfone organic solvent is 1: 100-1: 1000. According to the invention, benzene concentration in the standard sample can be increased, expiry data of the standard sample is prolonged to more than 1 year; benzene sampling weight is increased, weighing error is reduced, and the weighing relative error is reduced from 10% to 1%. The invention also provides a method for measuring trace quantity benzene in water by using the standard sample, and the standard sample does not influence the benzene measurement in headspace analysis.

The invention belongs to the field of medical examination, and relates to the analysis and measurement method of in vivo drugs, particularly to a method capable of measuring the concentration of Sodium Tanshinone IIA Sulfonate (STS) in human plasma. The method uses deuterium 5-dehydroepiandrosteronesulfate (DHEAS-D5) as an interior label, and the condition of a yellow light safety lamp without UV (light at the wavelength of 420 nm or below is removed) is adopted to control STS degradation during the blood sample treatment process, so that the accuracy of the method is ensured; after the blood sample is acidized using formic acid, a certain amount of organic solvent methyl alcohol and acetonitrile mixed liquor is added to enable protein to precipitate; a tandem mass spectrometry is used to measure the concentration of STS and the interior label; the quantitative linear range is 2-1000 ng / mL, the requirements of human pharmacokinetic studies are met. The method has the advantages that the less sample is required, the pretreatment is simple, quick, and sensitive, only general-type equipment and reagents are required, the analysis period is short, and the cost is low; the method is applicable to the detection of clinical blood routine STS concentration.

The invention relates to a detection method for simultaneously measuring OXC in human plasma and metabolite MHD and MHD-G, and belongs to the technical field of biological detection. An experiment is carried out by taking nitrazepam as an internal standard, and can simultaneously detect the plasma concentrations of the three compounds by adopting high performance liquid chromatography-tandem mass spectrometry after pretreatment through precipitation protein. The detection method is short in time, high in specificity and sensitivity, and convenient in operation, and is successfully applied to the analysis and research of oxcarbazepine in the human plasma and the metabolite thereof.

The invention discloses a method for measuring the concentration of 5,2`-dihydroxyl, 6,7,8,5`-tetramethoxyflavone (skullcapflavone II) in blood plasma. A certain amount of organic solvent is added to the sample to carry out the liquid-liquid extraction of the drug. After pretreatment, it is separated by a chromatographic column and detected by a mass spectrometer. concentration.

The invention relates to an internal drug assay determination method in the field of medical examination, which relates to a method for measuring human plasma imidazole density. It dose equal indicative elution on acid traveling phase condition after doing first treatment to the tested sample by protein depositing and uses ultraviolet detector to test it after chromatographic column separating.

The invention relates to the technical field of industrial emission, in particular to an infrared light detection method for rapidly detecting industrially discharged toluene. The method comprises the following steps of accurately extracting a toluene gas by using a microsyringe, and injecting the toluene gas into the syringe; at an industrial waste gas part, extracting the field air through an injector and marking as a waste gas sample; collecting the clean air by using the injector, and marking the clean air as a contrast sample; diluting a standard sample into a plurality of standard sample series by using the clean air, respectively sampling, and measuring the retention time and peak area by using a gas chromatograph; and determining the exhaust gas sample and the control sample by using the operation conditions for determining the standard sample series. According to the infrared light detection method for rapidly detecting the industrially discharged toluene, the toluene in the air is collected by using the microsyringe, and is directly fed into the gas chromatography and a hydrogen flame ionization detector for determination, so that the effect is good, the reproducibility of the method is better, and meanwhile, other substances in the air do not interfere with the determination under the conditions of the method.

The invention discloses a pretreatment method for detecting the content of phenolic impurities in a sample. The method comprises the following steps: weighing the sample, placing it in a volumetric flask, adding an acetonitrile solution of vitamin C, dissolving the sample, shaking well, and taking vitamin C dilute formic acid solution, filter, and the filtrate is used for instrumental analysis; the acetonitrile solution of vitamin C and the formic acid solution of vitamin C, wherein the content of vitamin C is 90-110 μ g / ml. By adopting the pretreatment method of the present invention, extremely low detection limits and quantitative limits can be achieved in the detection of phenolic impurities, and the repeatability is good; the stability time of the reference substance solution can also be extended to 30 hours, and the recovery of the solution after adding the standard can be achieved. The stability time is extended to 11 hours, and vitamin C and phenolic target substances can be effectively separated in the corresponding chromatographic system without interfering with the determination of target compounds.

The invention discloses a method for determining the concentration of 8-epiflavin E acetate in plasma. The method adopts a liquid chromatography-mass spectrometry system for determination. First, a sample to be tested is taken, a certain amount of an organic solvent protein precipitation agent is added to carry out protein precipitation, and after pretreatment , separated by a chromatographic column and detected by a mass spectrometer detector, the method of the invention is fast, accurate, highly sensitive, easy to operate, and suitable for determining the concentration of 8-epiflavin E acetate in plasma.