34results about How to "Symmetrical peak shape" patented technology

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.