7. Good Handling Practices for SPE Cartridges

Four common ways to drive flow through SPE cartridges:

1) Positive-pressure mode — A syringe-driven (air pressure) setup is convenient when sample count and load volume are small. Automated positive-pressure devices that deliver at a constant flow rate are widely used in water-quality analysis.

2) Vacuum mode — The most common approach. Use a dedicated vacuum manifold for multi-sample processing.

3) Centrifugation mode — Used with special formats such as 96-well SPE plates or spin columns.

4) Gravity-flow mode — Widely used in drug, pesticide-residue, and mycotoxin analysis. Prepare the required number of SPE cartridges and collection tubes; each step proceeds by gravity without constant operator attention.

Note: Flow rate varies depending on cartridge permeability, permeability differs, and the process may take longer