how the concentration of the extract analyszed can influnece on the quality of the GC/MS analysis. Should I use low concentrations or high concentrations?
1. Check the peaks symmetry.
2. For high concentrations the resolution will be lower. For GC-MS qualitative analysis you need well separated peaks (instead you can try to use deconvolution concept).
3. You don't have to dillute your extract you can try to increase the split ratio or lower the injection volume.
4. Remember that for low volatile compounds you should use splitless or on-column injection - in this case dillution is a must.
5. At all it depends on the purpose of your analysis :)
regards,
G
If I am understanding your question, then yes you can oversaturate. Try one level, then a 50% dilution. See which peak looks better. You can do this in a single run, so you should not use too much sample. Even working with the same material (primarily egg yolk lipids) we sometimes see better peaks at 80% dilute vs. our standard protocol, so we run several samples before collecting data to make sure we have diluted to optimum levels. We typically dilute all samples to the same level, but rarely will need to do a re-run if a sample is for some reason giving a weak or very strong signal. We keep the undiluted samples to the side (freezer, in our protocols) to make sure we have plenty of "stock" sample for re-runs.
1. Check the peaks symmetry.
2. For high concentrations the resolution will be lower. For GC-MS qualitative analysis you need well separated peaks (instead you can try to use deconvolution concept).
3. You don't have to dillute your extract you can try to increase the split ratio or lower the injection volume.
4. Remember that for low volatile compounds you should use splitless or on-column injection - in this case dillution is a must.
5. At all it depends on the purpose of your analysis :)
regards,
G
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