Solvent extraction
This technique separates the components of chemical mixtures by using the
dissimilar solubility properties of the components of the mixture in
different solvents. Extraction is used mainly to purify a reaction product
partially before final purification by recrystallization or distillation. The two common types of extraction process used in the laboratory are:
- Liquid-liquid extraction: this uses two immiscible solvents; the desired
compound in solution or suspension in one solvent is extracted into the
other solvent. For example, covalent organic compounds are extracted
from aqueous solution into dichloromethane, leaving the ionic byproducts
or reagents in the aqueous phase.
- Solid-liquid extraction: this involves the use of a solvent to remove
solvent-soluble components of a solid mixture.
