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

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 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.