Three different methods were developed with two different LC-MS/MS platforms. On the one hand, a Vanquish UHPLC system coupled to Q-Exactive Focus orbitrap mass spectrometer from Thermo Fisher Scientific (Waltham, MA, USA) was used for the LC-MS/MS spectra acquisition of standards (method 1). On the other hand, a Vanquish UHPLC system coupled to Orbitrap ID-X Tribrid mass spectrometer, also from Thermo Fisher Scientific, was used for the Flow injection analysis-MS/MS (FIA-MS/MS) spectra acquisition of standards (method 2); and for the LC-MS/MS spectra acquisition of standards, in-vitro oxidation, and proof-of-concept analysis of samples (method 3). The experimental conditions for each method are summarized in Table . MS/MS spectra of standards. A total of 54 and 57 individual oxylipin standards were injected with the methods 1 and 2, respectively, and 28 with both methods. Furthermore, 2 and 6 mixtures of oxylipin standards were injected with the methods 1 and 3, respectively. Altogether, it resulted in 119 files in .raw format. The details of the standards and the composition of the mixtures are available in Supplementary Table and Supplementary Table .