 Lipidomics has been greatly facilitated by recent advances in, and novel applications of, electrospray ionization mass spectrometry (ESI/MS).Lipidomics is a research field that studies the pathways and networks of cellular lipids in biological systems (i.e., lipidomes) on a large scale.It involves the identification and quantification of the thousands of cellular lipid molecular species and their interactions with other lipids, proteins, and other moieties in vivo.