Sample Concentration & Desalting
Sample concentration and desalting help prepare samples for LC or LC/MS by concentrating a dilute target, removing salts or non-volatile buffer components, or both. Start with the method and packing material, then choose a compatible trap system for your operating pressure and sample load.
In a typical trapping workflow, the target is retained while unwanted components are washed away, then eluted for analysis. Some methods instead retain the contaminant and allow the target to pass through.
1. Start with the application and packing material
The Optimize LC or LC/MS Trapping Guide describes how different packing materials are used for concentration and cleanup. The examples below are starting points for choosing a packing—not restrictions to a single trap family.
Peptide concentration & desalting
The guide describes a polymeric reversed-phase packing with retention similar to C8 for retaining peptides while salts and buffers are washed away.
Current phase names to compare: Peptide Concentration & Desalting Trap, Peptide, and Peptide ES-C18.
Protein concentration & desalting
The guide describes a large-pore polymeric reversed-phase packing with retention similar to C4 for concentrating proteins and removing salts or buffers.
Current phase names to compare: Protein Concentration & Desalting Trap and Protein.
Small-molecule concentration & desalting
The guide describes a hydrophilic C18 (ODS-AQ) packing for a small-molecule retention-and-wash method.
Current phase names to compare: Small Molecule, C18AQ, and C18. Verify the packing required for your method.
Other applications & sample types
For oligonucleotides, complex matrices, or other workflows, first establish whether the target or the unwanted component needs to be retained.
If the appropriate packing is unclear, ask Optimize for help with the selection.
About packing names: The listed phases are available product options, not automatically interchangeable materials. Match the packing to your application before choosing the hardware. See the Trap Chemistry Reference for more detail.
2. Compare trap systems by pressure and bed volume
Once you know which packing your method requires, compare the available product families. Each link opens the current product page, where you can choose the offered phase and cartridge configuration.
Pressure ratings vary by configuration. Always use the lowest applicable limit for the selected packing, cartridge, holder and fittings. The volumes above are packed-bed volumes, not maximum sample injection volumes or guaranteed analyte capacities.
Evaluating EXP? The EXP Trap Column Discovery Kit includes a holder and selectable cartridge packs for comparing configurations.
3. Complete the product selection
Confirm sample load: Consider sample volume, analyte mass, solvent/matrix, loading rate and the capacity needed for your method.
Confirm system requirements: Check operating pressure, on-line versus off-line workflow, flow direction and connection style.
Select the exact configuration: Match the cartridge to the correct holder with the Trap Compatibility & Holder Reference, then choose the available packing, size and pack type on the product page.
References & related applications
Need help choosing the right packing or cartridge? Tell us the sample type, what you want to retain or remove, your operating pressure and approximate sample load. Contact Optimize Technologies