troubling about silica colunm

[zhengmin]

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!

[Uwe Neue]

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.

[zhengmin]

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!

[Uwe Neue]

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.

[zhengmin]

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

[Alex Buske]

[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