C18 Silica Gel (Octadecyl Phase)

C18 silica gel is the most popular and versatile Reversed Phase, capable of hydrophobic interactions with a wide variety of organic compounds.

C18 silica gel is used for the separation of nonpolar to moderately polar compounds such as: Fatty acids, Glycerides, Polycyclic aromatics, Esters (phthalates), Fat-Soluble vitamins, Steroids, Prostaglandins, PTH amino acids.

Bonded Phases (Functionalized)/C18 Silica Gel

Sorbtech offers a broad range of bonding chemistries ranging from high hydrophilicity (Bimodal Aqueous) to high hydrophobicity (Trifunctional High Endcapping).

Type Functionality
C18 Aqueous Mixed Mode
C18 Aqueous II Mixed Mode
C18 MNE Monofunctional Non Endcapped
C18 MLE Monofunctional Low endcapped
C18 MHE Monofunctional High endcapped
C18 TNE Trifunctional Non Endcapped
C18 TLE Trifunctional Low Endcapped
C18 THE Trifunctional High Endcapped

Silica gel C18 is a type of stationary phase used in high-performance liquid chromatography (HPLC) to separate and analyze compounds in a mixture. It is made of silica, a naturally occurring mineral, and is modified with a hydrophobic (water-repelling) C18 hydrocarbon chain. This makes it highly efficient at separating compounds based on their hydrophobicity.

C18 is commonly used in the analysis of pharmaceutical compounds, environmental contaminants, and food additives. It is also used in the purification of biological samples, such as proteins and peptides.

It’s typically used in reversed-phase HPLC, where the stationary phase is hydrophobic and the mobile phase is aqueous. This type of chromatography is effective at separating compounds that are not very soluble in water. The C18 group on the silica gel allows it to interact with non-polar compounds in the sample, causing them to be retained on the stationary phase. When a compound is retained on the stationary phase, it takes longer to pass through the column and is separated from other compounds in the mixture.

In addition to its use in HPLC, C18 silica gel is also used in other chromatographic techniques, such as solid-phase extraction and gas chromatography. It is often used in combination with other stationary phases to improve the separation and analysis of complex mixtures.