Ascentis® HPLC Columns
Wide range of chromatographic selectivities
Enhanced polar compound retention
Ideal for LC-MS and all modern applications
These materials are hydrophobic (e.g., C18, C8, C4) functional groups bonded to silica particles. Mobile phases are
typically water with an organic modifier like methanol or acetonitrile.
Variations in retention behavior of the different reversed phase materials are caused by a variety of parameters such as:
surface coverage and chain length. As a general rule, the shorter the hydrocarbon chain, the shorter the retention time.
Each of the phases displays a unique selectivity. This means that changing from one C18 phase to another C18 will result
changes in elution times and possibly elution order.
We offer also columns packed with the following:
· Inertsil ODS
· Inertsil C8-3
· Inertsil C8
· Kromasil C18
· LiChrospher RP18
· LiChrospher RP8
· LiChrosorb RP18
· LiChrosorb RP8
· Nucleosil C18
Adsorption chromatography is usually achieved with non-derivatized silica packing materials. Retention of the analytes is
primarily caused by the interaction of polar groups with the silanol on the silica surface.
Adsorption chromatography is used for analytes with medium polarity that is soluble in organic solvents. It is not suitable
for polar analytes, because these analytes will interact with the silica surface, resulting in poorly shaped peaks or even no
elution at all. Variations in separation with silica gels from different manufacturers are caused by differences in shape and
pore size, particle size, surface area or types of silanol groups.
Polar bonded phases
The silica surface of polar bonded phases is derivatized with polar functional groups. Like non-bonded silica, these
packings are used in the normal phase mode, where they will display a different selectivity.