2-(2-Pyridyl)ethyl Silica Gel

Retention Mechanism
Anion-exchange

Sample Matrix Compatibility
Organic or aqueous Solutions

• Weak anion exchanger ideal for extracting strong basic compounds that remain charged at all pH levels
• Unlike conventional weak anion exchange SPE phases such as -NH2 (aminopropyl) that have a pKa of 9-10, a pH ≤ 7 is required to protonate or ionize the stationary phase to facilitate analyte retention. Elution is typically done by increasing the pH to 11 resulting in neutralization of the SPE phase.
• 2-(2-pyridyl)-ethyl silica gel has a pKa of ~6. Therefore, analyte elution is feasible at a pH ≥ 7. This characteristic is important for extracting analytes that are not stable (e.g. hydrolyzes) at high pHs typically required for elution when using traditional weak anion exchangers.
• Ideal for extracting acyl-coenzyme A esters from tissue.