1. Chemical reagent level Premium grade—GR For microbes—FMB Analytically pure—AR Industrial—TECH Chemically pure—CP Internship—PRACT Experimental Grade-LR For synthesis—FS Biochemical grade—BC Indicator—IND High performance liquid chromatography—HPLC Gas Chromatography-GC Biological staining-BS Liquid chromatography-LC Benchmark—PT For chromatography-FCP Atomic absorption—AAS Thin layer chromatography-TLC Infrared absorption—IR Spectral Pure—SP Nuclear Magnetic Resonance-NMR Spectral pure-UV Fluorescence analysis—FIA Synthesis—SYN 1. Overview of Chemical Reagents Chemical reagents are relatively standard substances for chemical research and component analysis, and are important conditions for scientific and technological progress. They are widely used in the synthesis, separation, qualitative and quantitative analysis of substances. The eyes of chemists are inseparable from the daily work of factories, schools, hospitals and research institutes without chemical regents. Chemical reagents are divided into organic reagents, inorganic reagents, biochemical reagents, indicators and standard samples according to their properties. 2. The purity of chemical reagents in China is still divided into: Chemical reagent grade, content, scope of application National standard reagent: This type of reagent is prescribed by China's national standards and is suitable for inspection, identification and testing Reference reagent (JZ, green label): As a reference substance, calibrate a standard solution. Premium grade pure (GR, green label): The content of the main ingredient is high and the purity is very high. It is suitable for accurate analysis and research work, and some can be used as a reference substance. Analytical purity (AR, red label): The content of the main components is high, the purity is high, and the interference impurities are very low. It is suitable for industrial analysis and chemical experiments. Chemically pure (CP, blue label): high content of main components, high purity, presence of interfering impurities, suitable for chemical experiments and synthetic preparation. Experimental purity (LR, yellow label): The main ingredient content is high, the purity is poor, the impurity content is not selected, only suitable for general chemical experiments and synthetic preparation. Teaching reagents (): A class of reagents that can meet the teaching purpose of students without causing deviations in chemical reaction phenomena. Specified grade (ZD), this type of reagent is a chemical reagent customized for a specific user according to the quality control indicators required by the user. High-purity reagents (EP): including ultra-pure, ultra-pure, high-purity, and spectrally pure, prepare standard solutions. The quality of this type of reagents focuses on: during the analysis of a particular method, it may cause deviations in the analysis results, and the content of impurities that interferes with component analysis or content analysis, but does not make high requirements for the main content. Chromatographically pure (GC): dedicated for gas chromatography analysis. Quality indicators focus on impurities that interfere with gas chromatographic peaks. High content of main ingredients. Chromatographically pure (LC): Liquid chromatography analysis of reference materials. Quality indicators focus on impurities that interfere with liquid chromatography peaks. High content of main ingredients Indicator (ID): used to prepare indicator solution. The quality indicators are the range of color change and the sensitivity of color change. Can replace CP, also suitable for organic synthesis. Biochemical reagents (BR): Preparation of biochemical test solutions and biochemical synthesis. Quality indicators focus on biologically active impurities. Can replace indicator, can be used for organic synthesis Biological staining agent (BS): prepare microbial specimen staining solution. Quality indicators focus on biologically active impurities. Can replace indicator, can be used for organic synthesis Spectral purity (SP): used for spectral analysis. Applicable to spectrophotometer standard, atomic absorption spectrum standard, atomic emission spectrum standard respectively Electronic pure (MOS): suitable for the production of electronic products, the content of electrical impurities is extremely low. Equivalent reagents (3N, 4N, 5N): The main component content is 99.9%, 99.99%, and 99.999% respectively. Electrophoresis reagents: quality indicators focus on the control of electrical impurity content. In addition, there are special reagents, the production volume is extremely small, and the production is almost on demand. The quantity and quality of such reagents are generally specified by users. Synthetic reagent: The so-called synthetic reagent: it is a kind of chemical reagent that strictly gives the product's various physical constants under the premise of indicating the main content of the ingredients. According to the content of the given main ingredients and the relevant physical constants, it is up to the user to determine whether it meets the needs of the job. If necessary, the user can make the corresponding purification. The quality indicators are clear and reliable. Such reagents are very suitable for synthetic preparation. In fact, the division of chemical purity and grade has been far from meeting the needs of scientific research and production due to the drafting of national standards, and has seriously hindered the production of chemical reagents in China. Relying on only a few existing national standards and industry standards, it is difficult to give such a large number of chemical reagents a quality specification; we cannot give all chemicals to a national quality standard. When it comes to reagents, people first think of whether it is analytically pure or chemically pure. Even when people buy it, no matter what the use is, they do not buy it if it is not "analytically pure". This is also the reason why many varieties that do not have national standards are baffled by giving the product a red AR label inexplicably and unfounded. It is also because in actual use, in many cases, the true "analytical purity" is not needed, and the illegal manufacturers deliberately label the industrial products with the "analytical purity" label, confusing the purity level. Although quality accidents will not occur in most cases, but However, it seriously interferes with the production and use of true "standard substances-analytically pure". Furthermore, since the number of conventional chemicals is huge, but only a few hundred varieties are classified as currently analytically pure or chemically pure, then, what is necessary? It is better to implement a "national standard reagent" in accordance with international norms and technical requirements. ", The standard is clearly used as the reference material for analysis and arbitration. The rest of the varieties are based on the "main content" to determine a "synthetic reagent" enterprise standard-"test reagent", so that our chemical reagent industry will go out of the law "death" mode. The so-called reagents: the reagents used in the test; that is, the chemical reagents required for the chemical test. One type is a relative standard substance, used for inspection, identification, and detection; the other type is a raw material substance, used for synthesis, preparation, separation, and purification. The current internationally accepted method is to indicate the grade and purity of chemical reagents according to the main content and physical constants of the chemicals. It is generally believed that when the main content, boiling point, melting point, density, refractive index, and even spectrum are known, the purity and applicable range of a substance can be completely determined. Pet Razor Scissors,Pet Curved Thinning Scissors,6.5 Inch Pet Grooming Scissors,Professional Dog Grooming Scissors Zhangjiagang Mister Tools Co., Ltd , https://www.msscissors.com