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Solvent compatibility - i.kovacs - 11-14-2014 06:28 PM

We have received this question to askthechemist@thalesnano.com:
Checking the solvent compatibility list ( http://thalesnano.com/flow-university/solvent-resistance ) and I have questions. Some solvents say room temperature only. The particular question is why should DMF not be used above RT and what would happen if it was attempted?
Some other solvents say elevated temperatures may reduce resistance. This means that the HPLC pump will push solvent through too quickly above the specified flow rate? Instrument will possibly destabilize? Any physical damage to instrument?

The solvent compatibility limitation’s may have different reasons. The most common ones are the degradation properties of the solvent, the chemical resistance reduction of the materials in the equipment and the possible reaction of the solvents with the reaction tube.
In the case of the DMF, it may decompose on elevated temperatures, and therefore it is not recommended to use above room temperature. If the residence time is short enough, then using DMF is possible.
If you see “elevated temperature may reduce resistance” it mostly means that the used materials' chemical resistance is decreased with the temperature increasing. If the system is used continuously within these conditions, it can result in the physically damage of some parts of the instrument.
Ie. if the H-Cube has a PEEK reaction line, then DMF is recommended to be used at room temperature only, it was not indicated if DMF interacts with the PEEK reaction line at higher temperature, more likely it was tested (by the supplier) only at room temperature and that is why that specification was provided.