Waters' Supercritical Fluid Extraction (SFE) Systems extract chemical compounds using supercritical carbon dioxide instead of an organic solvent. The supercritical fluid state occurs when a fluid is above its critical temperature (Tc) and critical pressure (Pc), when it is between the typical gas and liquid state. Manipulating the temperature and pressure of the fluid can solubilize the material of interest and selectively extract it. The sample is placed in an extraction vessel and pressurized with CO₂ to dissolve the sample. Transferred to a fraction collector, the contents are depressurized and the CO₂ loses its solvating power causing the desired material to precipitate. The condensed CO₂ can be recycled.

SFE applications in the food, pharmaceutical, and fine chemical industries:

• Decaffeinating of coffee and tea
• Extraction of essential oils (vegetable and fish oils)
• Extraction of flavors from natural resources (nutraceuticals)
• Extraction of ingredients from spices and red peppers
• Extraction of fat from food products
• Fractionation of polymeric materials
• Extraction from natural products
• Photo–resist cleaning
• Precision part cleaning