RtxPresentations07 - page 700-701

ComparisonofAPI vs. EI
• Atmospheric
Pressure Ionization
(API)
– MW confirmation
– Good for fragile
compounds
– Able to fragment in
the source
– Low (ppb) LODs in
SIMmode
• Electron Ionization
(EI)
– Ionization occurs in a
vacuum
– Standard libraries are
available
– Classical EI spectra
(similar toGC/MS)
– Higher LODs (ppmto
high ppb)