MS-based targeted metabolomics of eicosanoids and other oxylipins: Analytical variability and interlaboratory comparison of esterified oxylipin profile

IntroductionOxylipins are potent lipid mediators involved in numerous physiological and pathological processesand their quantitative profiling has gained a lot of attention [1]. To maximize the utility of theoxylipin profiling in clinical research it is now crucial (i) to assess its analytical variability; (ii) todetermine its comparability between laboratories and (iii) to identify putative critical oxylipins. Thesethree main challenges are addressed within the EU JPI HDHL*-Oxygenate project.Technological and methodological innovationTo address the challenges stated above, a SOP was established by a reference laboratory for the MSbasedtargeted metabolomics of total oxylipins (free + esterified, ~160 oxylipins) in human plasma[2]. The intra- and inter-day variabilities of each oxylipin were assessed. Then, the SOP wastransferred to 4 independent laboratories together with mixtures of internal standards, calibrantsand 7 different pools of plasma to determine the comparability of oxylipin profiles between labs.Results and impactThe cumulated intra-/inter-day variabilities revealed that 68 % of oxylipins (>LLOQ) have a CV