HPLC Column VDSpher 100 SIL, 5 µm, 20 x 150 mm

Both unmodified and several modified silica gels are available for normal phase (NP) chromatography. This enables a large number of normal phase separations.
The advantages of chemically modified silica gels, which allow rapid equilibration, reproducible, are particularly noteworthy Analyzes despite fluctuating water content in the mobile phase and a problem-free application of gradient methods. Depending on the type of modification, various mechanisms can be used for the separation:

• SIL: polar interactions, high silanophilic activity
• Diol: polar interactions, hydrogen bonds, silanophilic activity
• CN: polar interactions, π-π interactions, hydrophobic interactions, very low silanophilic activity
• CN-SE: polar interactions, π-π interactions, hydrophobic interactions, no silanophilic activity
• NH2: polar interactions, hydrophobic interactions, ion exchange, silanophilic activity
• AP: polar interactions, hydrophobic interactions, ion exchange, silanophilic activity
• DAP: polar interactions, hydrophobic interactions, ion exchange, silanophilic activity

It should also be taken into account that the silanol groups on the surface of the silica gel are slightly acidic, while amino modifications have a basic effect. Diol and CN, on the other hand, are considered neutral.