Trichloroethylene (TCE) is a volatile chlorinated hydrocarbon historically used as an industrial solvent. Due to its strong non-polar character and its ability to dissolve lipids, resins, and other hydrophobic compounds, it has also been employed in certain biochemical extraction procedures. Although its use in modern laboratories is limited because of safety and toxicity concerns, it remains a compound of interest in historical and specialized extraction protocols.
Chemical Properties
Trichloroethylene (C₂HCl₃) is a chlorinated ethene derivative characterized by a planar molecular structure containing three chlorine substituents (ClCH=CCl₂). It has a molecular weight of approximately 131.39 g/mol, a boiling point of 87.2°C, and a density of about 1.46 g/mL. The compound is a colorless liquid with a sweet, chloroform-like odor detectable at concentrations of roughly 2.6–21 ppm.
TCE exhibits relatively low solubility in water (approximately 1.1 g/L) but is miscible with many organic solvents, including ethanol and diethyl ether. While it is considered non-flammable under standard laboratory conditions, it can decompose under strong ultraviolet light or in the presence of oxidizing agents to form hazardous compounds such as phosgene and hydrogen chloride.
Biochemical Applications
In lipid biochemistry, trichloroethylene has historically been used for the extraction of hydrophobic molecules such as waxes, sterols, and chlorophyll from plant tissues. Its relatively high density allows efficient phase separation in biphasic extraction systems, and it has occasionally been used as an alternative to non-polar solvents such as hexane in older lipid extraction protocols related to Folch-type methodologies.
Additionally, TCE has been used to solubilize materials such as nitrocellulose or acetylated proteins in the preparation of chromatography supports. In earlier biochemical techniques, it also played a role in the immobilization of enzymes onto porous matrices or polymer beads. However, due to recognized health and environmental risks associated with trichloroethylene exposure, its use in modern laboratory workflows has largely been replaced by safer and more environmentally acceptable solvents.
