I conducted a Gas Chromatography experiment using Flame Ionisation Detector (FID).A capillary column was used.

Question

1)Blank
2) Standard
3) Sample
4)Blank
5)Standard
The above was injected into the system.

In 2)Standard chromatogram,a sharp, thin peak was observed between the 2 principal peaks. This peak had area count of less than 100.
This sharp peak was also seen in 4)Blank.

However, this sharp peak was not present in 5)Standard chromatogram.
Can you suggest a reason for this sharp spike/peak seen in 2) and 4)?

Answer 1

I would suspect contamination.

Answer 2

Dear Bob,
Can the sample results be accepted then if we exclude the "integration" of this "peak" from the chromatogram?

Answer 3

I'm not sure what kind of quantitative work you are doing, I would think it could be accepted if the outlying peak was not integrated with the other two peaks AND if the total of the three are not used somewhere.