Figure 2.
HCD/UVPD spectra of two double-bond positional PC isomers, sodium-cationized (A) PC 18:1(n-12)/18:1(n-12) and (B) PC 18:1(n-9)/18:1(n-9). These spectra were obtained by trapping the headgroup loss ions (m/z 625.5) generated by HCD and subjecting them to 10 laser pulses (193 nm) with 4 mJ per pulse.