Supercritical Fluid Chromatography is a modern separation technique that uses a supercritical fluid, most commonly carbon dioxide (CO₂), as the principal component of the mobile phase. In its supercritical state, CO₂ exhibits both gas-like diffusivity and liquid-like solvating power, enabling rapid, efficient, and tunable separations.
By adding small amounts of organic modifiers such as methanol or ethanol, the polarity of the mobile phase can be precisely adjusted to optimize selectivity for a wide range of analytes.
SFC provides short analysis times, low solvent consumption, and excellent chromatographic efficiency, making it a sustainable and cost-effective alternative to conventional HPLC. The technique is widely used for pharmaceutical, environmental, and natural product analysis, as well as for chiral separations where high selectivity and speed are essential.
Supercritical Fluid Chromatography bridges the gap between gas and liquid chromatography, providing a highly efficient, green, and flexible analytical platform. Its low viscosity and high diffusivity enable fast separations at reduced backpressure, while maintaining compatibility with common HPLC detectors such as UV, PDA, MS, and ELSD.
SFC is particularly valuable in enantioselective separations, lipid and fat-soluble compound analysis, and purification of thermally sensitive molecules, where traditional LC or GC methods may be limited.
The stationary phases used in SFC are typically silica-based materials, often identical to those used in normal phase or chiral chromatography. Common bonded chemistries include bare silica, diol, amino, cyano, and chiral selectors such as polysaccharide derivatives (cellulose or amylose carbamates).
Silica-based materials provide high mechanical stability and surface uniformity, essential for reproducible performance under supercritical conditions.
The flexibility of stationary phase choice allows SFC to be adapted for both achiral and chiral separations — from small, nonpolar molecules to complex pharmaceutical intermediates.
The mobile phase in SFC primarily consists of supercritical carbon dioxide (CO₂), often modified with 5–40 % of an organic co-solvent such as methanol, ethanol, isopropanol, or acetonitrile.
This combination enables precise control of elution strength and selectivity while minimizing solvent consumption. The use of CO₂ as the main component significantly reduces environmental impact and operating costs.
By adjusting pressure, temperature, and modifier composition, chromatographers can fine-tune solvation power, retention, and resolution — providing unmatched versatility compared to traditional liquid chromatography.
The retention mechanism in Supercritical Fluid Chromatography involves a combination of adsorption, partitioning, and polarity-driven interactions between the analyte, stationary phase, and supercritical mobile phase.
At low modifier concentrations, separations resemble normal phase behavior, while increasing modifier content enhances polar interactions and can shift the mechanism toward reversed phase-like characteristics.
This tunable balance makes SFC uniquely versatile — capable of separating nonpolar hydrocarbons, polar pharmaceuticals, and chiral compounds within a single platform.
| Name | Particle Sizes | Carbon Load | Pore Size |
|---|---|---|---|
| ReproSil Chiral-AM | 3 – 20 µm | 1 000 Å | |
| ReproSil Chiral-JM | 3 – 10 µm | 1 000 Å | |
| ReproSil Chiral-OM | 3 – 20 µm | 1 000 Å | |
| ReproSil Chiral-XM | 3 – 10 µm | 1 000 Å | |
| ReproSil Chiral-ZA | 3 – 10 µm | 1 000 Å | |
| ReproSil Chiral-MIA | 5 – 10 µm | 1 000 Å | |
| ReproSil Chiral-MIB | 5 – 10 µm | 1 000 Å | |
| ReproSil Chiral-MIC | 3 – 10 µm | 1 000 Å | |
| ReproSil Chiral-MIF | 5 – 10 µm | 1 000 Å | |
| ReproSil Chiral-MIX | 5 – 10 µm | 1 000 Å | |
| ReproSil Chiral-MIZ | 3 – 10 µm | 1 000 Å | |
| ReproSil Chiral-NR | 3 – 12 µm | 100 Å | |
| ReproSil Chiral-NR-R | 3 – 12 µm | 100 Å | |
| Reprospher 100 2-EP | 5 – 10 µm | 8 % | 100 Å |
| Reprospher 100 4-EP | 5 – 10 µm | 8 % | 100 Å |
| Reprospher 100 C18-WCX | 3 – 10 µm | 17 % | 100 Å |
| Reprospher 100 Diol | 3 – 10 µm | 7 % | 100 Å |
| Reprospher 100 PEI | 3 – 50 µm | 13 % | 100 Å |
| Reprospher HILIC-ARG | 3 – 5 µm | 15 % | 100 Å |