17.1 Flashcards
When organic compound placed in mass spectrometer, forms positive ion called ____________
Molecular ion
Mass spectrometer detects the __________ of the molecular ion
M/z
Mass to charge ratio
Find molecular mass how?
molecular ion peak has to be located - clear peak at highest m/z value (look at the very right side of mass spectrum)
Why see small peak after molecular ion peak on mass spectrum?
1.1% carbon is carbon-13 so very few number of molecules will have slightly larger mass/charge ratio
What is fragmentation?
Process in mass spectrometry that causes positive ion to split into smaller pieces, one of which is a positive fragment ion
Apart from the molecular ion, what are all the other peaks in a mass spectrum?
Fragment ions
Simplest fragmentation breaks molecular ion into…
2 species, positive charge fragment ion and radical
Radical uncharged, so not picked up in mass spectrum
How to use m and m+1 peak to work out number carbon atoms?
(Height of m+1/height of m) x 100