what instruments I need for identifying unknown volatile

[jiangds06]

CI, EI, high resolution?

[Don_Hilton]

The best tool to start with is an understanding of the sample. What is the sourde of the volatile and under what condition is it generated? What do you know abou tthe history of the sample? And, do you have any additional information.

If you have a "chemical" smell from a box used in packaging, the volatile can be as simple as a solvent - which can be identified by looking at the specificaitons for materials used in printing the box and a GC-FID or GC-TC run. (pretty cheap compared to purchasing a high res instrument - and a lot more simple to operate that CI)

[Peter Apps]

Welcome to the forum.

Let me guess that you googled "identify unknown volatile" or something similar, and this forum came up as one of the hits ? It is a serious question - I notice that first posts are often on a subject which has been discuused in the past few days, and I am interested in how people search for an find information on the internet.

If you search within the forum archives you will find that there is considerbale interesting discussion on what is required to "identify unknowns", and that the answer to you question might include NMR.

Peter

[bisnettrj2]

I bet "identifying unknowns" recovers your posts in particular, Peter! How does the African wild dog project go these days? I often think about your work while watching my four cats sniff each other and sniff me when I come back from a place they haven't been - give them a stink, and they'll be on it for hours!

[Peter Apps]

We are doing another round of confirming identities by injection of standards - I'm not sure that it qualifies as identification of unknowns ! At least I can claim that nobody knew that they we there !

We have a couple of intriguing genuine unknowns - two different peaks with very similar spectra that come up with impossible compounds on the library search; all the
"fits" contain sulphur or nitrogen but there is no signal for either on a PFPD. They will be on their way to another lab for high res MS as soon as I can get the export permits.

Peter

[jiangds06]

Thanks. i think I just go with gc-ms with ci and ei source.

We are doing another round of confirming identities by injection of standards - I'm not sure that it qualifies as identification of unknowns ! At least I can claim that nobody knew that they we there !

We have a couple of intriguing genuine unknowns - two different peaks with very similar spectra that come up with impossible compounds on the library search; all the
"fits" contain sulphur or nitrogen but there is no signal for either on a PFPD. They will be on their way to another lab for high res MS as soon as I can get the export permits.

Peter