Glycerophospholipids are glycerol-based phospholipids. They are the main component of biological membranes. Glycerophospholipids present a significant challenge in high level of accuracy in lipid quantitation, given the headgroup diversity, large number of possible acyl chain combinations, and vast range of ionization efficiency of species. The glycerophospholipids include hundreds of analytes encountered in routine profiling and over a thousand species detectable from repeated fragmentation scanning from some samples.