What filter should I use for general sample preparation?
The short answer: a 0.22 or 0.45 µm syringe filter, material matched to your sample solvent, used as the final step immediately before analysis.
Quick answer
For most general sample prep ahead of analysis, a small-format syringe filter at 0.22 or 0.45 µm, in a material compatible with your solvent, does the job. PES for aqueous samples, PTFE for solvents, nylon as a cost-effective organic-solvent option (checking analyte binding first).
Timing matters
Filter as the last step before analysis, not earlier in your prep sequence—filtering too early can let particulate back into the sample from subsequent handling steps, wasting the filtration step's purpose.
See our full sample preparation and filtration guide for the complete workflow logic.
Need a more specific recommendation?
Tell us your exact sample and instrument, and we'll confirm the right spec.