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Column Capacity

Posted: Fri Sep 29, 2006 7:16 pm
by delle.82
We are working on a calibration of our gc. The peaks are tailings so I think our problem is overloading the column. It is a PLOT column and I am trying to figure out the capacity of the column to assure overloading is actually the problem. Do any of you know where I can find information on this. The film width is 40m m. I found some tables but the width only went up to 5m m. The length is 30m and the diameter is 0.53mm. Any help would be greatly appreciated.

Posted: Sat Sep 30, 2006 11:51 am
by sadsal123
hi, what are you trying to analyse, what instrument are you using and what are your method parameters?

Posted: Sat Sep 30, 2006 7:51 pm
by Victor
If you want to find out whether overloading is the problem, reduce the size of your sample and see if it goes away. If it does not, then it is not an overloading problem.

Remember that volume overloading or mass overloading may occur so you might need a few injections to determine which is your problem, although I guess it is more likely to be the latter .

Posted: Mon Oct 02, 2006 12:13 pm
by chromatographer1
Victor gave you good advice.

There are other issues involved.

Just reduce your sample size and see what happens. Literature references give you a general answer which may not apply to your SPECIFIC problem.

best wishes,

Rod

Posted: Mon Oct 02, 2006 2:33 pm
by L4br4t
if the peaks are tailing, it is probably a leak, not over loading.
Over loading would produce a leading edge , instead of a tailing edge.

peak shape

Posted: Mon Oct 02, 2006 2:38 pm
by chromatographer1
Good morning, L4br4t

That is not always true. The temperature of the column, the nature of the support, the liquid phase, and the analyte itself all affect the peak shape.

Peak shape is not as straightforward as you have implied.

We don't wish to mislead delle.82.

best wishes,

Rod

Posted: Mon Oct 02, 2006 5:32 pm
by L4br4t
Yes, you are correct, it's not exactly that straight forward. I was only trying to suggest that the true cause of the problem be identified, before taking action, otherwise you could be in persuit of an untamed ornothoid without cause.
:wink:
I apologise if I mislead anyone in anyway.
Regards,
M