Chromatography Forum

Hi all, I am using a HP-Plot U column and it looks like the column has decomposed. I can see powder moving inside the column. it is fairly new column, one year old. Does anyone have any idea why this could happen?
I am using it in a Shimazdu 14B GC and using N2 as carrier gas.
Thanks
Jhansi

Have you injected any non-volatile material in solution onto the column?

If yes, then the powder you see may not be the porous polymer beads of the solid phase of the column.

But it may be so, and if the beads lose their grip to the surface they can be released and will migrate through the column to the detector, resulting in spike signals in an FID, but passes through a TCD, usually without harm.

If the loose beads stick to other beads or to the detector surfaces you may have issues with the chromatography performance.

When sticky stuff loses its 'stickiness' bad things happen. Water, solvents, air all contribute to the loss of adhesion.

Sales people always rejoice that columns do wear out. If they did not, then they would soon be out of work.

Rodney George
consultant

hi george,
Thanks for the reply. I have been analysing for methanol, methyl formate and formic acid in cyclohexane as solvent. Does cyclohexane effect the column? I see broad peak of cyclohexane during my analysis.

cyclohexane will not give a sharp peak on that column, or on any porous polymer column, The peak will tend to be broad.

I would expect that formic acid does not help the health of your column.

It might be cheaper to buy micropacked columns instead of capillary, but that is up to you. If you are not experienced with packed columns then you should stay with the capillary columns and just pay the price.

best wishes,

Rodney (last name is George, first name is Rodney)