Analysis of organic reagent is determined for inorganic elements in the separation and analysis of precipitant for enrichment, extraction agent, chelating agent and indicator for organic compounds, and not to refer to the general solvent, organic acid and organic alkali. These organic reagents must have good sensitivity and selectivity. With the development of analytical chemistry and the chemical industry, will be developed this kind of reagent sensitivity and better selectivity, such as since 1967 for some metal (such as alkali metal, alkaline earth metal) crown ether compounds and ammonium ion complexing is such.
Antibiotics (Antibiotic), also known as antibiotics, is a variety of organisms (plant, animal and microorganism, especially soil microbial metabolic activities) products, is also capable of selectively inhibiting the microorganisms in low concentration, virus and properties of tissue cells. The antibiotic has grown to more than 2000, but the actual application not much. The chemical structure of different antibiotics, character, according to their chemical structure can be divided into 32 categories, such as nucleosides, peptides, proteins, macrolide, polyene macrolides etc.