Chromatography Forum

Hi All,

Does anyone know if this is likely to damage this column. We are running it in normal phase mode (75/25 Hexane/Ethanol v/v) and would like to inject 50-100µL of a diluent of 95/5 Ethanol/water v/v containing sample of interest.

Is this level of water injection likely to lead to column damage or chromatography ill effects?

I think the manufacturer doesn't recommend it but I setup and ran an assay where we injected 2 uL of pure aqueous
into an ethanol hexane mixture. It ran for at least hundreds if not thousands of injections.

You probably won't damage the column (you only have a small amount of water, and lots of ethanol as a co-solvent), but you may run into the "strong diluent effect" which can easily cause peak shape problems.