Chromatography Forum

Hi Experts,

I am currently doing an HPLC stability assay using a mobile phase 0.04%Boric Acid in H2O:CH3CN (65:35)ph7.5 and a C18 RP column.I wash the column after the assay with H2O:CH3CN(65:35) , 10 column volume then with pure CH3CN ,10 column volume. Is it an appropriate practice?In the next assay day, since the column is store in CH3CN, is it a good practice to let the column pass with a 5 column volume H2O:CH3CN(65:35) before column equilibration with the mobile phase or should I proceed with column equlibration with the mobile phase?

pH over 7 with Boric Acid?. You probably have another component, right?. If it was boric acid itself, I would just equilibrate with the Mobile phase the next day (boric acid is soluble in ACN), but if you have some kind of buffer, then I would probably wash the column with a few volumes of 35/65 ACN/Water first. Or even pure water is OK to use.


Actually, you have very little Boric acid (or Buffer) in the system. Unless you have some garbage to flush out of the column at the end of the day, why not just program your pump to continue at 0.1ml/min overnight. And the next day you could start right away!

Thank you for your suggestion.