Figure 1.

(A) High-resolution base peak ion chromatogram of human milk obtained in the Orbitrap. (B) Mass tag between ammoniated and sodiated ions that serves as an additional triggering criterion. (C) High-resolution ion chromatogram of ion 876 Da (1,3-olein-2-palmitin, OPO) that serves as a basis for quantification. (D) Averaged product ion mass spectrum of parent ion 876 Da obtained in the linear ion trap in parallel to the high-resolution chromatogram; only monoisotopic product ions are present, representing the loss of PA (603.5 m/z), oleic acid (577.5 m/z) and of one ammonia unit (858.5 m/z).