Is C18 column reverse phase?

Is C18 column reverse phase?

A C18 column is an example of a “reverse phase” column. Reverse phase columns are often used with more polar solvents such as water, methanol or acetonitrile. The stationary phase is a nonpolar hydrocarbon, whereas the mobile phase is a polar liquid.

Is silica gel the stationary phase in column chromatography?

The most common stationary phase for column chromatography is silica gel, the next most common being alumina.

What is C18 silica?

C18 silica gel is used for Reversed Phase chromatography for the separation of nonpolar to moderately polar compounds such as: Fatty acids, glycerides, Polycyclic aromatics, Esters (Phthalates), Fat-soluble vitamins, Steroids, Prostaglandins, and PTH amino acids.

Which is better C8 or C18 column?

C18 is considered better for separating compounds such as long-chain fatty acids as compared to relatively small organic compounds. C18 has a longer carbon chain, but C8 has a shorter one. C18 has higher retention while C8 has shorter retention. C18 has higher hydrophobicity, but C8 has a lower hydrophobicity.

What is reverse phase silica gel?

Reverse phase silica gel is used in organic chemistry for the purification and isolation of synthetic compounds (i.e. post-reaction “harvesting” of chemical products). As as result of this end-capping, C18 silica gel is insoluble in polar solvents including methanol.

How do C18 columns work?

How Does HPLC Work?

1. A small volume of your sample (in the liquid phase) is injected into your stationary phase.
2. A pump moves the liquid down the column using high pressure.
3. As the individual components exit the column, a detector measures them.

Is silica used in column chromatography?

Column chromatography is done with chromatographic quality silica gel. Neutral silica gel is used for chromatography of triphenylmethyl ethers, and is prepared by treatment of silica gel with ammonium hydroxide, followed by reactivation at 150° (15).

How does silica gel column chromatography work?

Silica gel and alumina are highly polar so they interact strongly with polar compounds and solvents, and weakly with nonpolar molecules. The stationary phase is loaded into the column as a slurry with the solvent and is then packed by flowing solvent through the stationary phase.

What is a C18 column made of?

Octadecylsilane (C18) has 18 carbon atoms. On the other hand, Octylsilane(C8) has only 8 carbon atoms on the column parking bonded to silica (Si). C18 will tend to retain more than C8. In that, if a similar compound was eluted on the two columns, it will elute faster on C8 and slower on C18.