HPLC column & limited pH

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Hamidreza
Hamidreza's picture
HPLC column & limited pH

Hi there,
I have a HPLC column with silica packings that are limited to working between pH 2 and pH 7.
We want to determine some substances in our reactions. All reactions are done in organic phase (acetone or acetonitril). Now how can we check pH for this organic phase? And how can decrease or increase it? As you know pH meter is not useful for this system!
Any partial solution to protect our column? (We don’t want change the column! I know some column is wider pH range)
Regards,
Hamid

Dr. Analytical
Dr. Analytical's picture
The pH limitations on LC

The pH limitations on LC columns only apply when your mobile phase contains a buffer that is outside the listed pH range. This pH is determined in the aqueous solution before mixing with the organic solvent. So, the actual pH might be different in the mixture, but the only way we can get a measurement is by analyzing the water.

If your mobile phase does not contain any additives that would change the pH, then you do not have to worry about it. If you can provide more information on the column and your separation problem we may be able to provide some additional advice on column care and other things to avoid.