Ekstraktans

Ekstraktans is a term used in chemistry to denote an extractant, a substance that promotes the selective transfer of a solute from one immiscible liquid phase to another during solvent extraction. Extractants are typically organic compounds chosen for their affinity to the target solute.

In a liquid-liquid system, the extractant binds or solvates the solute and forms a complex that partitions into the extract phase. The process relies on chelation, ion pairing, or hydrophobic interactions and is usually reversible, enabling back-extraction.

Extractants are classified by mechanism and structure. Acidic extractants (such as organophosphorus acids) extract metal cations by forming neutral complexes; basic extractants (amines) operate via protonation and ion exchange; neutral or solvating extractants (ketones, ethers, phosphates) extract through solvation. Newer approaches include ionic liquids and polymer-supported extractants.

Ekstraktans are central to hydrometallurgy for separating and purifying metals (rare earths, uranium, copper) and for pharmaceutical and fine-chemical separations. They are also used in environmental cleanup and analytical chemistry to preconcentrate trace solutes.

Many extractants are volatile organic compounds with health and environmental risks; handling requires proper ventilation, containment, and waste treatment.

Development of extractants paralleled advances in solvent extraction during the 20th century, driven by industrial metallurgical and chemical-processing needs.