HPLC Bonded Phases

Silica

Silica is a normal phase material and is used for separating polar organic compounds

Nitro

Normal phase material that is used for aromatic and other conjugated compounds

TMS, SAS, Trimethyl

C1 is a reversed phase material offering unique selectivity for polar and non-ionic organic compounds.

Diol, Glycerol

Reversed phase or normal phase material. Reversed phase is used for Gel Filtration Chromatography of proteins and peptides. Normal phase offers similar selectivity to silica, it is not deactivated by small amounts of water

Butyl

C4 columns often show similar selectivity to C18 columns, although sometimes offer different selectivity towards polar compounds

C₆H₅

Reverse phase material that is useful for analyzing aromatic compounds

Phenyl shows weak dipole - induced dipole interactions with polar analytes. Usually, this type of bonded phase is used for group separations of complex mixtures. Amino-compounds show some specific interactions with phenyl modified adsorbent.

Hexyl

Reversed phase material. Useful for ion-pairing chromatography

Quarternary Amine, SB (Strong Base)

Strong bases are normally used as anion exchangers. These are useful for separating nucleotides, nucleosides and organic acids.

MOS, RP-8, LC8, Octyl

A common reverse phase material that has similar applications to C18, although it is less retentive

Sulphonic Acid, SA (Strong Acid)

Strong acids are normally used as cation exchangers. They are useful for separating organic bases.

Octadecyl, ODS, RP18

The most common reversed phase material. C18 can be used in a broad range of applications and is strongly retentive of non-polar solutes. Often there are different versions (e.g. ODS1/ODS2 etc). These indicate different carbon loading or degrees of endcapping.

DEAE, Diethylaminoethyl, Weak Base, PEI, Polyethyleneimine

Weak bases are used as weak anion exchangers. They are most useful for analysing and purifying acidic proteins and peptides.

CPS, PCN, Cyano, Cyanopropyl, Nitrile

A cyano modified surface is very slightly polar. Columns with this phase are useful for fast separations of mixtures consisting of very different components. These mixtures might show a very broad range of retention times on the usual columns. Cyano columns could be used on both normal- and reversed-phase modes of HPLC

CM, Carboxymethyl, Weak Acid

Weak acids are used as weak cation exchangers. They are most useful for analysing and purifying basic proteins and peptides.

Amino, APS

Amino-phase is a weak anion-exchanger. This type of column is mainly used in normal-phase mode, especially for selective retention of aromatic compounds.