MS/MS spectra from the dissociation of lipid IVA by (a) CID, 1-, (b) IRMPD, 1-, (c) 193 nm UVPD, 1-, and (d) a-EPD, 1-•. Red arrows highlight the product ions that undergo sequential IRMPD. The 1- precursor was m/z 1403.8 and the 1-• precursor (for a-EPD) was m/z 1402.8.