C8 and C18 are both types of reverse-phase chromatography columns, but they differ in their:
Carbon chain length:
- C8 columns have an octyl (8-carbon) chain.
- C18 columns have an octadecyl (18-carbon) chain.
Hydrophobicity:
- C8 columns are less hydrophobic than C18 columns.
Retention characteristics:
- C8 columns retain smaller, more polar molecules.
- C18 columns retain larger, more non-polar molecules.
Separation range:
- C8 columns are suitable for separating smaller molecules (e.g., metabolites, small peptides).
- C18 columns are suitable for separating larger molecules (e.g., proteins, large peptides).
Column selectivity:
- C8 columns have a different selectivity profile compared to C18 columns, which can affect peak resolution and order.
In summary, C8 columns are used for smaller, more polar molecules, while C18 columns are used for larger, more non-polar molecules. The choice between C8 and C18 depends on the specific separation requirements and the properties of the molecules being analyzed.
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