Mistaken the post-column mobile phase and pre-column phase

[Manik]

Hi, I am Manik

I am a student who barely know anything about HPLC. I made a huge mistake in putting the pre-column and post column mobile phase. Anyway, my analytical condition as follows:

HPLC (Shimadzu, Japan), equipped with CDD-6A electroconductivity detector, double column of Shimpack SCR-102H (300×8 mm i.d., Shimadzu, Japan) and a guard column (50×8mm). Mobile phase containing 5 mM p-toluene sulfonic acid (pre-column) and post column detection was 5 mM p-toluene sulfonic acid, 100 μM EDTA and 20 mM Bis-Tris, the two were mixed (1:1, v/v).

One time during an analysis, I had mistaken 5 mM p-toluene sulfonic acid, 100 μM EDTA and 20 mM Bis-Tris as pre-column mobile phase and 5 mM p-toluene sulfonic acid as post column mobile phase. Since then the retention time delayed eventhough I had changed the mobile phase correctly.

So my question is:
Did 5 mM p-toluene sulfonic acid, 100 μM EDTA and 20 mM Bis-Tris damage the column (Shimpack SCR-102H ) in some or other way?
What is the influence of 5 mM p-toluene sulfonic acid, 100 μM EDTA and 20 mM Bis-Tris on the column described?
What should I do to make the retention time normal again?

Looking forward for your kind reply

[Markus Laeubli, Metrohm]

Dear Manik

I assume the the column is not damaged by this wrong eluent unless the pH of that eluent is outside of the columns specs.
The BIB/TRIS sholud be washed out in a short time. EDTA may be removed with a few injections of a e.g. Ca standard.

Hope this helps