Quinoline

As a key chemical raw material, quinoline is a colorless or straw yellow clarity oily liquid with a special pungent odor and slight hygroscopicity. It has a melting point of -17 — -13℃, a boiling point of 237.7℃ (at normal pressure), a density of approximately 1.093g/cm³ (20℃), a flash point of 99℃ (closed cup), slightly soluble in cold water, and easily soluble in ethanol, ether, benzene, chloroform and other common organic solvents. It should be stored and transported in strict accordance with the specified conditions to maintain its stability and quality.

For quality control, quinoline complies with strict industrial grade standards: purity ≥98.0% (GC); related substances (individual ≤0.1%, total ≤2.0%); appearance (colorless or straw yellow clarity oily liquid, no obvious impurities) and identification (gas chromatography retention time + infrared spectroscopy). It also controls water content, residual solvents (methanol ≤0.3%, ethanol ≤0.5%), heavy metals (≤10 ppm), loss on drying (≤0.5%) and residue on ignition (≤0.1%) to ensure batch consistency and product safety.

Industrially, quinoline is widely applied: in the pharmaceutical field, it is used to synthesize antimalarial drugs, nicotinic acid derivatives, hydroxyquinoline drugs and intermediates for antitumor and antibiotic drugs; in the dye industry, it is used to prepare cyanine blue pigments and photosensitive pigments; in the rubber industry, it serves as a vulcanization accelerator; in agriculture, it is used to produce pesticides such as 8-hydroxyquinolinone; it can also be used as an organic synthetic solvent, alkaline condensing agent, metal preservative and gas chromatography stationary liquid.

Quinoline is a hazardous chemical (UN 2656, Class 6.1 Toxic Substance, Packing Group III). It is harmful if swallowed or in contact with skin, causes eye and skin irritation, is suspected of being carcinogenic and mutagenic, and is toxic to aquatic organisms with long-term environmental hazards. Proper protective equipment should be worn during operation, and storage and transportation must strictly follow the specifications for hazardous chemicals.