In Jan Article in LC/GC by prof. Hinshaw
I have read that it is possible to "recover" a column by rinsing it in reverse direction.
The producer of the column I use does not give any hint as to what solvent should be used ( INNOWAX), also, how is the rinsing done - by mounting the column in reverse direction and injecting the solvent, or outside the chromatograph?
The question is probably stupid, but nevertheless it came up.
Does it make sense to make a cleanup runs by injecting the solvent used in the sample prior to a set of injections?

We've used SGE CWR-10 column rinsing kit, part #0625026 (Agilent #9301-0982). We use dichloromethane for our methyl-silicone type columns. Helium pressure is used to force the solvent back through the capillary.

rinse.cdf a.jpg (76 k)

Pawel,
I am familiar with the Innowax column specifically, but you want to make surte it is a bonded phase (polymeric) otherwise you stand the possibility of dissolving the phase and stripping it from the column.

Pawel,

Sometimes it is safer and certainly easier just to remove 1 meter pieces from the head of the column.
Usually any problem contamination is trapped in the first few meters of column. Remove pieces until you fix the problem.

You do not lose much resolution going to even a 25 meter column from a 30 meter column.

Solvent rinsing can damage a column even if bonded and done carefully, and you might not rinse off the contamination. You might end up buying a new column anyway.

OR

A better habit with dirty samples is to attach a deactivated guard column to the head of the analytical column and replace as needed.

OR

buy a 60 meter column when you need only a 30 meter. Cut the column in half and use 5 meter pieces of the second 30m column as guard columns for the first. That may save you a lot of money over time.

Rodney George

we have used db-5 column, if the contamination in the column, we will give the maximum column temperature about 260 deg centigrade and will inject 05 ul of methanol for four or five times.