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- Posts: 2
- Joined: Mon Jun 04, 2018 4:26 pm
Forewarning, I am a 1st year graduate student using GC/MS for the first time. My thesis revolves around the determination of these organic volatile compounds at a known amount on cotton fabric.
I have run into a problem where I cannot seem to find any published articles (or dissertations, or even a thesis) on a method of extraction using direct injection. It seems when it is done, it is more so using headspace and a SPME fiber. So far I have run known standards of these compounds using direct injection using methanol as a solvent and the peaks come out fine.
From what I can gather, direct injection gives a greater limit of detection than headspace SPME preparation. This is all in the context of forensic trace analysis for organic gunshot residue. Why is SPME so common? What are the advantages it possesses over direct injection?
If it helps, I am on an Agilent 6890N system. Any input into this subject, as well as any links to relevant articles on direct injection vs SPME, or research involving known amounts of these compounds (or organic volatile compounds in general) on fabric would be greatly appreciated.