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- Posts: 29
- Joined: Fri Nov 12, 2004 10:49 am
Dear Friends,
Please, consider this situation:
We have been performing a new GC-HeadSpace (GC-HS) residual analysis with use of Internal Standard (IStd) and Reference Standard (RStd). The IStd and RStd areas have been almost equal (~2200ua and ~2750ua, respectivelly, with RSDs at ~2.5%). But the IStd areas in the sample injections have been reduced to 460ua with RSD at ~3.5%.
One important point must be considered because the Volatile Compounds Content of this sample is 80% and these volatile compounds have been limited the vials internal disponible space to presence of the IStd, wich probably present lowest Vapour Pressure over the HS conditions, so its areas for the sample must be lowest than the similar Reference Standard injections.
Normally, the IStd areas are equal to sample and Reference Standard injections, because the add quantity is the same for both.
Do you suggest different explanation for this?
Carlos Teixeira[/b]
Please, consider this situation:
We have been performing a new GC-HeadSpace (GC-HS) residual analysis with use of Internal Standard (IStd) and Reference Standard (RStd). The IStd and RStd areas have been almost equal (~2200ua and ~2750ua, respectivelly, with RSDs at ~2.5%). But the IStd areas in the sample injections have been reduced to 460ua with RSD at ~3.5%.
One important point must be considered because the Volatile Compounds Content of this sample is 80% and these volatile compounds have been limited the vials internal disponible space to presence of the IStd, wich probably present lowest Vapour Pressure over the HS conditions, so its areas for the sample must be lowest than the similar Reference Standard injections.
Normally, the IStd areas are equal to sample and Reference Standard injections, because the add quantity is the same for both.
Do you suggest different explanation for this?
Carlos Teixeira[/b]
