SiliaBond Reversed Phases

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In reversed-phase chromatography, the packing material is always hydrophobic (non polar) while the mobile phase is polar. The more hydrophobic the packing material, the more retention of non polar analytes.

Usual reversed-phases are standard alkyl chains grafted on silica (C18, C8, C4, C1) and cyclic or aromatic functions (Phenyl, Pentafluorophenyl, Cyclohexyl).

Important parameters to keep in mind in reversed-phase chromatography:

• Carbon load (% C) will give the relative hydrophobicity of the packing media. Most of the time, it varies between 4 % and 19 %.
• Endcapping: it is impossible to react with all available silanol groups (free -OH groups on the silica surface) when functionalizing silica. But these free silanols are acidic and will react with basic compounds, so we endcap them with a capping agent to avoid non-specific bindings.