The quality levels of chemical reagents are complex, and there are many varieties, which are particularly confusing. There are 225 kinds of general conventional varieties (a class of reagents), which are basically complementary in China's Beijing, Tianjin, Shanghai, Xi'an, Chengdu, Guangzhou and Shenyang chemical reagent bases. The second type of reagent is used in almost all fields, and it is also a necessary variety for manufacturers, with about 1800~2000 varieties, and such reagents are in high demand and widely used. There are about 3000~6000 varieties of three types of reagents, and most of their use fields are related to the national economy and people's livelihood, such as chemical, metallurgy, electric power, food, medicine and health and other industries that are specifically used in the industry.
In China, there are 225 kinds of chemical reagents expressed in three grades: excellent purity, analytical purity, and chemical purity, in accordance with the national standards of the People's Republic of China and the standards issued by the former Ministry of Chemical Industry. These 225 kinds of chemical reagents stipulate the basis of the content of chemical reagents in China in the form of standards. The content of other chemicals is determined by this basis, and its content is determined by measurement. Therefore, the quality of these chemical reagents is very important. At the same time, these 225 chemical reagents have become basic varieties due to their extremely wide range of uses. These 225 varieties have been marked in the chemical reagent catalog. In addition, there are special reagents, which are produced in very small quantities, almost on demand, and their quantities are generally specified by the user.
Common quality levels
Superior Grade Pure (GR, Green Label): High principal component content and high purity, suitable for precise analysis and research work, and some can be used as reference substances.
Analytical Purity (AR, Red Label): High principal component content, high purity, low interference impurities, suitable for industrial analysis and chemical experiments. Equivalent to ACS class (American Chemical Society standard)
Chemically pure (CP, blue label): high content of principal components, high purity, and interference impurities, suitable for chemical experiments and synthetic preparation.
Experimental Purity (LR, Yellow Label): High content of principal components, poor purity, and impurity content are not selected, which is only suitable for general chemical experiments and synthetic preparation.
Indicators and stains (ID or SR, purple label): Requires specific sensitivity.
Designated grade (ZD): chemical reagents customized for specific users according to the quality control indicators required by users.
Electron Pure (MOS): Suitable for the production of electronic products with very low levels of electrical impurities.
Equivalent reagents (3N, 4N, 5N): the principal component content is more than 99.9%, 99.99% and 99.999%, respectively.
Spectral purity: 99.99% purity of the main components