Simultaneous quantification of fatty acids in serum with dual derivatization by Liquid Chromatography-Tandem Mass Spectrometry.

Fatty acids have multitudinous biological functions and play a crucial role in many biological processes, but due to poor ionization efficiency and lack of appropriate internal standard, the comprehensive quantification of fatty acids by liquid chromatography-tandem mass spectrometry is still challenging. In this study, a new, accurate and reliable method for quantifying 30 fatty acids in serum using dual derivatization was proposed. Indole-3-acetic acid hydrazide derivants of fatty acids were used as the internal standard and Indole-3-carboxylic acid hydrazide derivants of them were used to quantify. The derivatization conditions were systematically optimized and the method validation results showed a good linearity with R 2 > 0.9942, low detection limit (0.03-0.6 nM), precision (1.6% - 9.8% for intra-day and 4.6% - 14.1% for inter-day), recovery (88.2% - 107.2% with RSD < 10.5%), matrix effect (88.3% - 105.2% with the RSD < 9.9%) and stability (3.4% - 13.8% for fatty acids derivants in 24 h at 4°C and 4.2% - 13.8% for three freeze-thaw cycles). Finally, this method was successfully applied to quantify fatty acids in serum samples of Alzheimer's patients. In contrast to the healthy control group, nine fatty acids showed a significant increase in the Alzheimer's disease group. This article is protected by copyright. All rights reserved.