Selection of HILIC columns to handle matrix effect due to phospholipids

Background: Phospholipids from biological samples are a source of matrix effect in liquid chromatography mass spectrometry. While the behavior of phospholipids has been documented under reversed-phase chromatography, there is a lack of information concerning the selectivity of hydrophilic interaction chromatography (HILIC) towards phospholipids. Results: Human plasma extracts were used to evaluate retention times and matrix effects associated with phospholipids under HILIC conditions. It was observed that phosphatidylcholine and lysophosphatidylcholine phospholipid retention times vary greatly between columns operated in different HILIC conditions. Therefore, matrix effects associated with phospholipids could present a quantitation problem if not evaluated thoroughly during method development. Conclusions: Analytical chemists should carefully choose the right combination of sample preparation and chromatographic conditions when working under HILIC conditions to avoid variable results.