Sciencemadness Discussion Board

FTIR SPECTRUM

enrico88 - 25-8-2011 at 11:22

CAN YOU HELP ME INTERPRETATING THIS SPECTRUM??... RESIDUES OF KEROSNEE UNBURNED

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Magpie - 25-8-2011 at 11:31

enrico please do not double and triple post. It is against forum policy and is very irritating. It is especially irritating to those who may be most capable of helping you. I suggest you delete the first two posts, assuming that they are indeed duplicates of the last post.

DDTea - 25-8-2011 at 14:27

You don't have to explain every wiggle in the spectrum. Focus on the prominent peaks:

3820,30 ; ~3740; ~3275; ~3090; 2838,29; 2341,40; 1557,38; and 1109 cm^-1

Also, it looks like you've got some significant atmospheric contamination in this spectrum. That prominent peaks around 2341,40 cm^-1 are probably due to CO2. CO2 also has prominent absorptions above 3600 cm^-1. If there's CO2 in your spectrum, there's probably water vapor there too--and in fact, you can see some water vapor absorptions above 3600 cm^-1.

Spectrum of CO2: http://webbook.nist.gov/cgi/cbook.cgi?Spec=C124389&Index...

Take home message: ignore everything above 3600 cm^-1.

How did you collect this spectrum? Was it on a diamond ATR crystal, perchance? If I recall correctly, diamond has a strong absorption around 2800 cm^-1...

Pretty much, it looks like you forgot to run a background spectrum :)

[Edited on 8-25-11 by DDTea]