Determination of lignans in flaxseed using liquid chromatography with time-of-flight mass spectrometry

A new method of flaxseed-derived lignan determination was developed using HPLC with high-resolution time-of-flight MS (TOF-MS), optimized, and compared to two existing methods (HPLC/MS/MS and GC/MS). The limits of detection (LODs) for HPLC/TOF-MS (0.002-0.043 pg) were comparable with those of the optimized and improved HPLC/MS/MS (0.001-0.015 pg), whereas the LODs for the optimized GC/MS were higher (0.02-3.0 pg, yet lower than reported before). Using the newly developed detection and separation methods, several key flaxseed sample preparation parameters (including extraction, hydrolysis, and sample purification) were evaluated resulting in the development of efficient protocol for lignan quantification from flaxseed hulls and embryos. The results confirmed the importance of quantification of both aglycones and unhydrolyzed glucosides in order to obtain the total lignan estimates.