The Standardized 5-Step SPE Workflow
In 2026, the SPE workflow is optimized for reproducibility. The process relies on a "Bind and Elute" strategy where target analytes are captured on a sorbent bed while the messy matrix is discarded.
1. Conditioning: Activating the sorbent ligands with an organic solvent (e.g., Methanol) to ensure they are accessible for the sample.
2. Equilibration: Rinsing with a buffer to match the sample’s pH and ionic strength, preventing "chemical shock" to the analytes.
3. Sample Loading: Passing the liquid sample through the cartridge at a controlled rate (typically 1 mL/min).
4. Washing: Removing weak interferences (salts, proteins, lipids) using a solvent strong enough to clean but weak enough to leave the analyte bound.
5. Elution: Using a strong solvent to break the chemical bond and collect the concentrated analyte in a clean vial.