Amino Propyl (NH2) -- silica-based polar bonded phase with basic character; can be used as a polar sorbent, like silica, with different selectivity for acidic/basic analytes or as weak anion exchanger in aqueous medium; applications include phenols and phenolic pigments, petroleum fractionation, saccharides and drugs and metabolites
Cyano Propyl (CN) -- silica-based polar bonded phase; can be used as less polar alternative to silica in normal-phase applications or as less hydrophobic alternative to C18 or C8 in reversed-phase applications; typical applications include drugs, drug metabolites and pesticides
Diol -- silica-based polar bonded phase with neutral character; can be used as an alternative to silica in normal phase applications, where the acidic character of silica is undesirable or as very weakly interacting phase in aqueous applications; applications include antibiotics from cosmetics; isolation of proteins or peptides by hydrophobic interaction chromatography
Silica -- polar sorbent, used primarily to adsorb analytes from non polar solvents like hydrocarbons, chloro- or fluoro-substituted hydrocarbons or less polar esters and ethers; elution with more polar solvents like polar esters, ethers, alcohols, acetonitrile or water; the binding mechanism can be hydrogen bonding or dipole-dipole interaction; silica can also be used in aqueous medium as a cation exchanger of intermediate strength.
Alumina (A, B & N) -- similar in use to silica; available in acidic, basic and neutral high activity grades; alumina also exhibits specific interactions with the pi-electrons of aromatic hydrocarbons, making it useful for applications like crude oil fractionation; acidic and basic grades can also be used as low-capacity ion-exchangers
Florisil® -- polar, highly active, weakly basic sorbent for adsorption of low to moderate polarity species from nonaqueous solutions; specifically designed for the adsorption of pesticides using official AOAC and EPA methods; other applications include polychlorinated biphenyls (PCB’s) in transformer oil