Profiling of complex lipids in marine microalgae by UHPLC/tandem mass spectrometry

Microalgal lipids are of great interest for their potential as food and feed ingredients, nutraceutical and cosmetic components, and as source of energy. Glycerol-based lipids can constitute up to 50% or more of the biomass of microalgae. How synthesis of these products takes place is still poorly explored, although remarkable differences with plants and among microalgal species have already emerged. These differences attain to both lipid class and fatty acyl composition, which could be modulated by specific growth conditions. Here we present a new method based on UHPLC coupled to high resolution tandem mass spectrometry for targeted analysis of the main lipid classes, i.e., glycolipids, phospholipids and triacylglycerols, applied to five marine microalgae exhibiting a great diversity in lipid composition. The LC/MS/MS approach is integrated with a recently proposed MTBE-based protocol for lipid extraction and the entire workflow is of general application to lipid profiling of cell extracts from different sources.