First, a very high-l​​evel description of “supercritical.” The three states of matter are gas, liquid and solid. In the supercritical fluid region, matter under the influence of certain temperature and pressure levels becomes supercritical, where a difference between the gaseous and liquid states can no longer be observed.

In supercritical fluid chromatography (SFC), the mobile phase com​​monly is supercritical carbon dioxide. Carbon dioxide is normally a gas (people and animals exhale it) and when it is under a certain pressure and cold enough, it forms dry ice. When the temperature and pressure reach a certain highpoint, the CO₂ becomes supercritical.

Supercritical carbon dioxide for chromatography yields quick results and offers environmental advantages. It is stable, relatively inexpensive, non-flammable, non-toxic, and easy to remove from the sample. Because many compounds cannot be separated using supercritical CO₂ alone, it usually is used in combination with an​​other solvent, such as methanol, ethanol, and others.

While the prin​​ciples of SFC are much like those of HPLC, the supercritical fluid used as the mobile phase offers decreased viscosity, allowing SFC to run at a higher flow rate than HPLC. Therefore, SFC is generally a three to four times faster process than HPLC. Other advantages of SFC over HPLC include its “green” features:

• Greatly reduces solvent consumption (up to eight times less organic solvent used)

• Less solvent waste

• Up to seven times lower energy consumption for solvent removal

• CO₂-neutral: reuses CO₂ captured from other processes or the atmosphere

• Environmentally friendly alternative to hazardous organic solvents

• CO₂ is nontoxic and with appropriate co-solvents is safe to use with food and pharmaceutical products

All those ben​efits are yours with the ACCQPrep® SFC from Teledyne LABS.​

To learn more, read What is SFC?​

​​For a full list of product specifications, see the datasheet​​.