Memory effects with GC
Posted: Wed Mar 14, 2012 11:47 pm
Dear all,
we are trying to optimize the behavior of a GC that we have been setting up for the last months to measure CO, CH4, CO4, SF6 and N2O.
Now we are trying to obtain good chromatograms for the sample we analyze but we see that there is some memory effect in the system (after one "sample" analysis (zero air, ambient aire or Ar-CH4) we have tested nitrogen and we still obtain the desired peaks but with a lower intensity). We have been checking it for leaks or backflows, but we have discarded these possibilities. We think that probably somehow a portion of the sample gets stucked to a column or the methanizer.
The last option, that of the methanizer, do you think that could be pausible? Could the sample get adsorbed to the catalyst since it is old and probably not well compacted (we have not conditioned it either)?
Thanks in advance for your help.
we are trying to optimize the behavior of a GC that we have been setting up for the last months to measure CO, CH4, CO4, SF6 and N2O.
Now we are trying to obtain good chromatograms for the sample we analyze but we see that there is some memory effect in the system (after one "sample" analysis (zero air, ambient aire or Ar-CH4) we have tested nitrogen and we still obtain the desired peaks but with a lower intensity). We have been checking it for leaks or backflows, but we have discarded these possibilities. We think that probably somehow a portion of the sample gets stucked to a column or the methanizer.
The last option, that of the methanizer, do you think that could be pausible? Could the sample get adsorbed to the catalyst since it is old and probably not well compacted (we have not conditioned it either)?
Thanks in advance for your help.