*2.7.4 Identification of the carbon chain size*

TAG is defined in this chapter as a series of species with the equal total number of acylated carbons (CN) and the equal number of double bonds (DB), regardless of its constitution in FA. So each TAG group has a unique chemical formula and a precise mass. Ammonium salt is added to the mobile phase so the TAG are detected as ammoniated adducts (to become more stable and avoid the formation of different adducts with the same molecule) in the positive ionization mode ESI+. The most abundant TAG groups contain 26–54 acyl CN and 1–8 DB, with molecular mass ranging from 500 to 1000.
