Please help!
I connected a BRAND NEW Column to a HPLC Agilent 1100/1200 series : Tosoh Bioscience TSKgel G3000SWXL, 7.8mm x 30cm, 5µm. connected to a BRAND NEW TSKgel QC-PAK GFC Guard Column for 7.8 mm. I ran the column with HPW filtered water when I received the column. (5 hours at a flow of 0.3 mL/min 72 bars.)
Then, in Mobile Phase (0.2M Potassium Phosphate, 0.25M Potassium Chloride, 10% Isopropyl Alcohol, pH 7.0 ± 0.2) at flow of 0.3 for 1.5 hours, 72 bars.
The base line was at zero.

I did a test injection of mobile phase (20 microliters) and the baseline was steady and between zero and negative (-)5 at a run time of 50 mins.

The column coupler is a hard firm plastic(the ones that come on the brand new tosoh columns) with metal inlet.

Multiple injections after, same results.

I changed the column coupler for better connection and less dead volume. While doing that I connected the 30cm column in the wrong flow direction. I started a test injection and quickly stopped when I saw the online view of the run's baseline increasing and huge peaks.
I stopped the flow and disconnected the column and reconnected it correctly.
After 20 mins the baseline dropped to -375 and currently there.

COA says it can be washed backwards but I am not sure if mobile phase will effect packing inside column.

Currently the column in water at a flow of 0.1, 72 bars of pressure

May Column or detector be ruined?




Also , before I connected this column I had the same set-up with older tosoh column producing good blank injections of mobile phase. The other analyst attached an older column due to qualification purposes. Any help will do? ( 2 years experience in HPLC)

Any suggestions?