GCMS interpretation

[aafrin]

hi,
I have analyzed a few samples extracted in diethyl ether using GCMS. The samples were given to an institute for analysis which provides the results in JPEG format. I don't have the raw files for the data. The hits provided donot give the exact mass of the compound. For one retention time there are 2 to 3 close hits but I am not able to decide which one to consider. Please suggest me a way to analyze the data. Is there any online tool to identify the compounds with the fragmentation pattern I have?

[Consumer Products Guy]

This should be in Mass Spec section

GCMS with electron impact does not always give an ion for the molecular weight, may be MW less a group that gets split off, depends on the structure.

I'd say obtain reference materials of the hits that are decent and use retention time as a tool to positively identify.

We assay polymers and surfactants here that each chain length has similae EI spectrum, and retention time is a valuable tool that should not be overlooked. Another usefull tool is to match up retention time on columns of two different polarities - now that's a trick from hands-on experience!