The extracted ion chromatogram (EIC) of non-epoxidized PC 34:1 reveals two signals that are separated in the mixture of all three isomers but do not significantly differ. The first signal at around 22 min RT (Figure ) overlaps with the PC 34:1 mixture prior to reaction (Figure ). The coelution of snand DB position GPL isomers is also consistent with literature reports that demonstrated the inability to separate most GPL snand DB position isomers when using a RP column, unless the attached FA residues on sn-1 and sn-2 significantly differ in length or DB number. This is in contrast to E/Z DB stereoisomers that are regularly separated. Therefore, the second signal in Figure