Determination of physical constants 1. Melting point: According to the pharmacopoeia method, take the average of three measurements plus the correction value of the thermometer. The variety whose melting point phenomenon is difficult to observe is added as the melting point of DSC. 2. Specific rotation: According to the method prescribed by the Pharmacopoeia, the blank is measured three times, and the sample is measured five times, and the average value is calculated. 3. Absorption coefficient value: Two samples in parallel are required for the measurement, and each sample is measured at two concentrations (the concentration of the pharmacopoeia ± 10%). Purity inspection (standard), focusing on thin-layer chromatography and high-performance liquid chromatography for "related substances" inspection: 1. Thin-layer chromatography: Two expansion systems are required, and the color development sensitivity is 0.1%-0.2% of the detection amount. The amount of the control solution is a gradient, and the amount of the sample solution is the doubling amount of the pharmacopoeia and the pharmacopoeia. The result of the experiment is to report the Rf value of the sample and the scene of the impurity. When the amount of impurities is large, it is necessary to determine whether the sample is decomposed by a two-way expansion method. 2. High performance liquid chromatography: requires two mobile phases or two columns of different models, the minimum detection amount should reach 0.1% of the detection amount, the injection volume is the doubling amount of the pharmacopoeia amount and the pharmacopoeia amount, and the diode array detection is performed. Peak purity, the mass was calculated by normalization or the main component self-dilution control method. Content determination Two methods are required to determine the content. Generally it is the volumetric method and chromatography. The capacity method requires two people to measure 3-5 parts. The parallel experimental results of each person and the relative deviation of the experimental results of both individuals should be less than 0.3%. High performance liquid chromatography requires three concentrations as correction factors, and the precision requires an RSD of less than 1.5%. If the content is determined by spectrophotometry, the reference method must be used, and the E value method can only be used as a reference. The chemical reference for the determination of the content is also required for DSC purity determination.
In this category there are all kinds of Face Brushes for applying facial makeup,like Foundation Brushes, Concealer Brushes, Contour Brushes, Bronzer Brushes , Powder Brushes , Highlighter Brushes, Lip Brushes and other face brushes. Each brush features a perfectly shaped brush head made with synthetic bristles for its function.
Face Brushes Face Makeup Brushes,Face Brushes,Most Popular Makeup Brush,Types Of Makeup Brushes SHENZHEN MERRYNICE COSMETICS CO., LTD / MERRYNICE COSMETICS USA GROUP , https://www.merrynice.com
Standardization process of Zhengzhou Weier reference substance