Sequence and charge shape the starting point
Hydrophilic sequences may be compatible with aqueous media, while hydrophobic sequences can show limited solubility, adsorption or aggregation. Net charge, pH, concentration, modifications and counter-ions also matter, so the product name alone cannot determine a solvent.
Use the analytical method as the constraint
Start from the batch documentation and the validated or agreed method. Use a mild compatible aqueous system when suitable; if a difficult sequence needs pH adjustment or an organic co-solvent, confirm that the final composition is compatible with the column, detector and acceptance procedure.
- Target concentration and final pH
- Aqueous and organic solvent compatibility
- Container, filter and tubing adsorption
- Mixing time and visible or method-based checks
- Stability over the sample-hold interval
Document recovery, not just visual clarity
A clear solution does not prove complete recovery, and haze does not automatically prove degradation. A fit-for-purpose procedure records the preparation sequence and shows that transfer, filtration and hold time do not create a misleading result.