Fig. 5.

Tandem mass spectrum of Fmoc-derivatized phosphoethanolamine-containing lipids by NL of the Fmoc moiety. Phosphoethanolamine-containing species were derivatized by the addition of an equimolar amount of Fmoc-Cl as described in the legend to Fig. 3. NL tandem mass spectra of Fmoc-PE (inset A) and Fmoc-lysoPE (inset B) were acquired by coordinately scanning both the first and third quadrupoles with a mass difference (i.e., NL) of 222.2 u, corresponding to the NL of a Fmoc moiety, while collision activation was performed in the second quadrupole at collision energy of 30 eV and collision gas pressure of 1 mTorr. Inset C indicates the presence of many very low-abundance PE molecular species in the region. IS, internal standard.