Simultaneous determination of fatty acids and related N-Acylethanolamines in rat plasma, rat tissue, and human plasma using UPLC-MS/MS

A sensitive and specific method for the simultaneous determination of palmitoyl ethanolamide (PEA), oleoyl ethanolamide (OEA), linoleoyl ethanolamide (LEA), 1-palmitoyl glycerol (1-PG), 1-oleoyl glycerol (1-OG), 1-lino-leoyl glycerol (1-LG), palmitic acid (PA), oleic Acid (OA), and linoleic acid (LA) in rat plasma and liver by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been developed. Multiple-reaction mode (MRM) of a triple quadrupole mass spectrometer was used for detection. A reverse phase C8 column was used for chromatographic separation, and an 11.5-minute gradient elution time was used. Deuterated internal standards included 2-AG-d5, OEA-d4, LEA-d4, and OA-d9. In terms of linearity, accuracy, repeat-ability, intermediate precision, recovery, matrix effect, and stability, this newly designed method was approved. These nine lipids were successfully determined using this method in two sample groups: plasma from individuals with non-alcoholic fatty liver diseases (NAFLD) (n = 40) and healthy individuals (n = 40), as well as plasma and liver samples from rats with NAFLD (n = 15) and healthy ones (n = 11).