Is area% a useful parameter in FID-GC?

[Mike H.]

I've never viewed area% as a valid parameter to base purity on in FID-GC because the compounds' responses depend on the amount of oxidation and it seems like it would be like comparing apples to oranges, but I received a method from another site where minimum area% purity is one of the acceptance criteria. Could someone explain why area% in FID-GC could be a valid way to characterize a compound? Thx

[aidnai]

What you say about apples/oranges and oxidation is true, and you're right to be wary. However, in a QC setting for example where you know what your impurities are, you can account for the differences beforehand (when you establish the criteria) and use %area as a shortcut later.

[Mike H.]

That makes sense. It's only useful in specific cases where you define what compounds should be present and have already determined the RRFs experimentally, but definitely not intended in instances when unknown compounds are observed in the chromatography. That was what I was thinking, but it's was useful to have this confirmed. Thanks.

[AICMM]

If it is all alkene alkane this might still hold up. FID's have wonderfully consistent response factors.

Just a thought.

Best regards,

AICMM