Figure 2.

Typical mass spectra showing the total ion counts (TICs) of GluCer (A) and LacCer (E), commercial standards purified from buttermilk, separated using hydrophilic interaction liquid chromatography (HILIC) and detected in positive ion mode as protonated molecules. Corresponding mass spectra are presented in (B) and (F), respectively. The tandem mass spectrometry (MS²) fragmentation of the GluCer m/z 798.71 amu ion (C) and the LacCer m/z 946.59 amu ion (G) are shown, followed by the corresponding three-stage mass spectrometry (MS³) fragmentations of the daughter ions with m/z 618.68 amu (D) and m/z 604.66 amu (H), respectively.