Figure 1 of Chen, Mol Vis 2014; 20:1605-1611.

Figure 1. Representative electrospray ionization tandem mass spectrometric analysis of phosphatidylcholine (PC) extracted from control rats in positive ion mode. A: Representative precursor ion scan (PIS) scanning for m/z 184, characteristic of the PC class of lipids. B: Representative PIS scanning for m/z 184, including an internal standard (m/z ratio of 650) for ratiometric quantification.