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Egg lecithin is usually extracted chemically using ethanol, acetone, petroleum ether but not benzene or hexane due to restrictions on residual solvents by the pharmaceutical regulations. [2] It is an emulsifier, especially for parenteral use since it does not need to be metabolized.
In the 1980s, the European Union began harmonising regulatory requirements. In 1989, Europe, Japan, and the United States began creating plans for harmonisation. The International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) was created in April 1990 at a meeting in Brussels.
Tetrachloroethylene is a nonpolar solvent for organic materials. Additionally, it is volatile, relatively stable, and non-flammable. For these reasons, it became a leading solvent in dry cleaning operations worldwide beginning in the 1940s. [13]
Solvent Density (g cm-3) Boiling point (°C) K b (°C⋅kg/mol) Freezing point (°C) K f (°C⋅kg/mol) Data source; Aniline: 184.3 3.69 –5.96 –5.87 K b & K f [1 ...
13 C NMR Spectrum of DMSO-d 6. Pure deuterated DMSO shows no peaks in 1 H NMR spectroscopy and as a result is commonly used as an NMR solvent. [2] However commercially available samples are not 100% pure and a residual DMSO-d 5 1 H NMR signal is observed at 2.50ppm (quintet, J HD =1.9Hz).
Deuterated chloroform is a general purpose NMR solvent, as it is not very chemically reactive and unlikely to exchange its deuterium with its solute, [9] and its low boiling point allows for easy sample recovery. It, however, it is incompatible with strongly basic, nucleophilic, or reducing analytes, including many organometallic compounds.
The most important is dichloromethane, which is mainly used as a solvent. Chloromethane is a precursor to chlorosilanes and silicones . Historically significant (as an anaesthetic), but smaller in scale is chloroform, mainly a precursor to chlorodifluoromethane (CHClF 2 ) and tetrafluoroethene which is used in the manufacture of Teflon.
Many solvents are volatile and can easily be evaporated using rotary evaporation. Even less volatile solvents can be removed by rotary evaporation under high vacuum and with heating. It is also used by environmental regulatory agencies for determining the amount of solvents in paints, coatings and inks.