6results about How to "Stable retention time" patented technology

The invention discloses a method for determining ceftizoxime sodium for injection and impurities thereof by liquid chromatography, which comprises the following steps: taking octadecylsilane chemically bonded silica as a filler for the ceftizoxime sodium for injection; the column temperature is 35 DEG C; the flow rate is 0.8 ml / min; the detection wavelength is 254 nm; the sample injection volume is 20 microliters; carrying out gradient elution by using a mobile phase A and a mobile phase B; according to the method, the retention time of the impurity 16 can be stabilized, the impurity 09 and the impurity 12 can be effectively separated, and the method has important significance on quality control of the ceftizoxime sodium for injection.

The invention establishes a rapid, accurate and efficient high performance liquid chromatography-mass spectrometry detection method for detecting the common antipsychotic drugs in the hair, and the concentration of ten common antipsychotic drugs or metabolites in the hair can be quantitatively detected at the same time; the method is suitable for clinical blood concentration monitoring, drug poisoning screening and large-scale biological sample detection, and has very significant significance in clinical use.

The invention relates to a method for simultaneously determining related substances of glycine and methionine. The method comprises the following steps: step 1, preparing a blank auxiliary material solution; step 2, preparing a test solution; step 3, preparing a reference solution; step 4, preparing a system applicable solution; and step 5, detecting. Compared with a traditional method, the method has the advantages that the related substances in the glycine and the methionine can be simultaneously determined, the sample pretreatment is simple, the compound retention time is stable, the instrument configuration requirement is low, the analysis cost is reduced, the sensitivity is high, the impurity separation degree is good, and the related substances in the glycine and the methionine can be effectively separated.

The application provides a construction method of a characteristic map of Adiantum capillus-veneris and a content determination method of characteristic components of the Adiantum capillus-veneris. The construction method of the characteristic map comprises the following steps: taking chlorogenic acid, 3-O-p-coumaroyl quinic acid and kaempferol-3-O-beta-D-glucuronide as reference substances to obtain reference substance solutions; mixing the Adiantum capillus-veneris with an extraction solvent and performing heating reflux treatment or ultrasonic treatment, and then filtering the Adiantum capillus-veneris after cooling to obtain a test sample solution; placing the test sample solution and the plurality of reference substance solutions in a high performance liquid chromatograph, determining high performance liquid chromatograms of the test sample solution and the reference substance solutions, taking the high performance liquid chromatograms of the reference substance solutions as a control, selecting common peaks from the high performance liquid chromatogram of the test sample solution, and obtaining a characteristic map of the Adiantum capillus-veneris. The above method has excellent precision, repeatability, stability and durability, and is significantly superior to traditional single component determination or non-standardized methods.

The invention relates to the technical field of traditional Chinese medicine, in particular to a preparation method of a roxburgh rose leaf extract, a construction method of a specific chromatogram and a detection method of brachyphyllinic acid and ellagic acid in the roxburgh rose leaf extract.The preparation method comprises the steps that roxburgh rose leaf decoction pieces are decocted twice to obtain decoction liquid, and the decoction liquid is filtered; the roxburgh rose leaf extract is prepared from roxburgh rose leaf decoction pieces, through an accelerated stability test, the content and the moisture content are relatively stable, and specific chromatograms and a content detection method are good in specificity, repeatability and stability.

The application discloses a method for detecting the concentration of formic acid in high-concentration sulfuric acid by high performance liquid chromatography, and belongs to the technical field of concentration detection. The method comprises the following steps: establishing a formic acid standard curve, filtering a sample through an acid-resistant filter membrane, directly injecting the sample, and detecting and calculating the formic acid content by using high performance liquid chromatography. The method is suitable for a 4-8 M sulfuric acid system, and can realize effective separation and accurate quantification of formic acid in a high-sulfate background. The method is simple in operation, and is suitable for rapid detection of formic acid in an industrial process and a complex reaction system.