Rapid Characterization of the Human Breast Milk Lipidome Using a Solid-Phase Microextraction and Liquid Chromatography Mass Spectrometry-Based Approach

Human breast milk (HBM) is a biofluid consisting of various biomolecules such as proteins, lipids, carbohydrates, minerals and bioactive substances. Due to its unique and complex composition, HBM provides not only nutritional components required for the growth of the infant, but also additional protection against infections. Global insight into the composition of HBM is crucial to understanding the health benefits infants receive from breastfeeding and could be used to improve the composition of milk formula for babies that cannot be breastfed. To improve global profiling of the HBM lipidome, a new analytical approach based on solid phase microextraction (SPME) and liquid chromatography mass spectrometry (LC-MS) was developed. The new extraction method allows for the rapid and simple extraction of a broad range of lipids directly from HBM samples. Moreover, the optimized two-step lipid extraction protocol ensures high lipidome coverage without using toxic solvents such as chloroform. The use of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) and an automated search of a lipid database allows comprehensive identification of the lipids contained in HBM. The demonstrated analytical approach based on SPME sample preparation and LC-QTOF-MS is rapid, free of toxic solvents, and suited for the qualitative analysis of the HBM lipid composition.