Chromatography Forum

Hi...

A senior once informed me that if microbial contamination occur, we should remove the column and flush the system using IPA.
My question is, do we need a HPLC grade solvent for this kind of practice (flushing). According to the solvent supplier, it is ok to use the kind of analysis grade solvent for flushing purpose only and not for elution. However, the technical guy from HPLC-selling company told us to use the HPLC grade even for flushing.

Please help to share your experience/ knowledge.

Thank you

The only guarantee in this situation is that if you leave multiple grades of a chemical close enough to the LC, the wrong one will get used for analysis at some point.

Three points come to my mind:
1.) The price difference is not enormous (except if you use LC-MS utltra grade solvents)
2.) Flushing (as I assume from your message) will not happen too often
3.) Storage capacity of solvents is usually a problem in every lab.

Conclusion: Use the same grade of solvent for everything that is pumped through your HPLC.

Jörg