Supercritical Fluid Methods

Natural products from plants and microorganisms have been of great interest and importance for many years. They are the source of many pharmaceutical compounds, flavors, fragrances, spices, oils, and food and beverage ingredients. The use of supercritical fluid extraction (SFE) as a general extraction strategy for a wide range of “active ingredients” or “analytes” from plant and microbial samples is of particular importance in the extraction of “unknown” natural products or for preparing whole-organism extracts for chemical analysis, bioassay, or screening programs. SFE offers many advantages: it leads to lower solvent usage, controllable selectivity, cleaner extracts, and less thermal degradation as compared to conventional solvent-extraction and steam-distillation methods. There has been a spurt of activity in the use of supercritical fluids for extraction purposes; SFE is emerging as an attractive alternative to conventional solvent extraction and steam distillation. Also, strict environmental regulations concerning the use of common industrial solvents, most of which are hazardous to human health, are indirectly contributing to the explosive growth of SFE technology.