Rising curve at the end of chromatogram

[ito_miura]

Hi all.
I have a problem where the curve at the end of the chromatogram is rising instead of flat, near the base peaks. Is this a normal occurence? Otherwise, why could possibly make the chromatogram spike up?

Thanks in advance.

[DR]

details please.

[Bigbear]

Yes details.
If it is what I think, yes its normal. Most columns give a slightly rising baseline due to the temp. ramp. It looks worse if there is no major peaks to normalize on.

[ito_miura]

dear all,

so it's normal if there's no peak anymore in the end analysis the baseline is rising up?

[Peter Apps]

Let's try to get just one very basic piece of information - is this gas chromatography or liquid chromatography ?

Peter

[ito_miura]

dear peter,

it is gas chromatrography with mass spectrometry and also pyrolysis...

[Peter Apps]

Then the rising baseline is normal (presuming that you are doing temperature programming) and is usually due to column bleed and the elution of unresolved heavy compounds.

Peter

[ito_miura]

okey thank you if this is normally happen......

have a nice day....