Chromatography Forum

Happy new year,everyone!
It is the first time for me to use silica column.
Dose it damage the column when I use the 1% of acetic acid in my mobile phase (chloroform)? The impurity peak which was eluted before main peak in my mobile phase(chloroform which containing 1% of acetic acid ) was eluted behind the main peak in other mobile phase (chloroform which containing 0.1% of acertic acid). Is it true that the changing of the rention time is caused by the high concentration of acetic acid? How can I cleaning the column? And how should I flush the normal phase system after work?
Thanks of all!

No, you did not damage the column. However it may take some time to get the acidic acid off again, if you want to do that. In your case, a reequilibration with the lower concentration of acetic acid may not be that terrible, and jmay ust take some time.

No, you did not damage the column. However it may take some time to get the acidic acid off again, if you want to do that. In your case, a reequilibration with the lower concentration of acetic acid may not be that terrible, and jmay ust take some time.

Thank you very much!
I see now, I don't worry again. Now I flushed the column with isopropanol for 1 hour.
I want to ask another question: Which solvent should I use to flush the column end of work every time? Is isopropanol need? Or only is chloroform need?Thank you!

For a silica column in normal-phase chromatography, I would leave the column in mobile phase. Then equilibration is fast the next time the column is used.

Uwe Neue:
Thank you very much! I see now.

[quote]I want to ask another question: Which solvent should I use to flush the column end of work every time? Is isopropanol need? Or only is chloroform need?Thank you![/quote]

That depends on quality of chloroform. I would just flush the column for some minutes with isopropanol.

Alex