Solventgrade

Solventgrade is a term used in chemistry to describe the quality and purity category of solvents used in laboratories and industry. It is not a single standardized grade; rather it is a labeling convention that indicates a solvent meets the purity requirements appropriate for a given application or standard.

Common grades include ACS grade, reagent grade, HPLC grade, spectroscopic grade, and anhydrous grade. ACS grade is widely used in general laboratory work and meets standards of the American Chemical Society; HPLC grade is refined to minimize UV-absorbing impurities and residual water for chromatographic applications; spectroscopic and UV grades are purified to suit specific analyses; anhydrous grades are dried to remove water for moisture-sensitive reactions; technical or industrial grades may be purer than classroom solvents but may contain higher levels of certain impurities.

Purity is described by certificates of analysis and is verified by testing for water content (often Karl Fischer titration), residual solvents, inorganic impurities, trace metals, and organic contaminants. For ethers such as diethyl ether and THF, peroxide content is also specified due to safety concerns.

Manufacturers employ distillation, drying, purification, and sometimes filtration to achieve target grades, and store in appropriate packaging to prevent moisture uptake and oxidation. Certificates of analysis accompany shipments and provide the measured purity, moisture level, and other relevant specifications.

Choosing the right solvent grade is essential: using a lower grade can introduce impurities that affect reactions, separations, or instrument sensitivity.