Chemical reagent quality level is complex, variety is numerous, especially chaos. There are 225 kinds of general conventional varieties (first class reagents), that is, necessary varieties. The chemical reagent bases in Beijing, Tianjin, Shanghai, Xi 'an, Chengdu, Guangzhou and Shenyang are basically complementary to each other. Second class reagents are almost used in all fields, and are also necessary varieties for manufacturers. There are about 1800 ~ 2000 varieties. This kind of reagents are in large demand and widely used. There are about 3000 ~ 6000 varieties of the three reagents, and most of them are used in specific industrial reagents related to the national economy and people's livelihood, such as chemical industry, metallurgy, electric power, food, medicine and health and other industries.
In China, a total of 225 kinds of chemical reagents are used 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 in the form of standard, set the basis of the content of chemical reagents in China. The content of other chemicals is determined on this basis, through the determination to determine its content. Therefore, the quality of these chemical reagents is very important. At the same time, these 225 kinds of chemical reagents because of the wide range of applications and become the basic varieties. These 225 varieties have been marked in the chemical reagent catalogue. In addition, there are special reagents, the production is very small, almost on demand production, the number is generally specified by the user.
High purity (GR, green label) : the main component content is very high, high purity, suitable for accurate analysis and research work, some can be used as a reference material.
Analytical pure (AR, red label) : high content of principal components, high purity, low interference impurities, suitable for industrial analysis and chemical experiments.
Chemical purity (CP, blue label) : high principal component content, high purity, interference impurities, suitable for chemical experiments and synthetic preparation.
Experimental purity (LR, yellow label) : high principal component content, poor purity, impurity content does not make choice, only suitable for general chemical experiments and synthetic preparation.
Indicator and stain (ID or SR, purple label) : required to have a characteristic sensitivity.
Specified grade (ZD) : chemical reagents customized for specific users according to the quality control indicators required by users.
Electronic purity (MOS) : suitable for the production of electronic products, the content of electrical impurities is very low.
Equivalent reagent (3N, 4N, 5N) : principal component content of 99.9%, 99.99%, 99.999% and above.
In addition, it is still divided into the following 20 levels.
AAS atomic absorption spectrometry, BC biochemical reagent, BP British pharmacopoeia, BR biological reagent, BS biological stain, CR chemical reagent, EP special purity, FCP chromatography, FMP microscope, FS synthesis, GC gas chromatography, GR superior pure reagent, HPLC high pressure liquid chromatography, ID indicator, IR infrared absorption spectrum, MAR microanalysis Reagents, NMR nuclear magnetic resonance spectroscopy, OAS organic analysis standard, PA analysis, PRACT practice, PT reference reagent, PURISS pure, PURUM pure, SP spectral pure, TECH industrial, TLC TLC, UP ultra pure, USP, UV UV spectrophotometry pure, JX teaching reagent, MI medical grade, I industrial grade, F food grade, M cosmetic grade, S solid, L liquid, E fine, C coarse
Obviously, it is far from satisfying the demand of scientific research and production to divide the quality standards of these chemical reagents into the above several quality levels.