Targeted lipidomics profiling of acute arsenic exposure in mice serum by on-line solid-phase extraction stable-isotope dilution liquid chromatography-tandem mass spectrometry.

Lipidomics is the area of study dedicated to the comprehensive analysis and characterization of the functions and metabolism of lipids in biological samples. One of the most comprehensively studied classes of lipids is polyunsaturated fatty acids (PUFAs). Eicosanoids are a series of bioactive lipid mediators that are metabolized from PUFAs and generated majorly from the precursor arachidonic acid. This study identified the profiles of target eicosanoids after acute exposure to arsenic. The principle objective was to determine and validate 10 eicosanoids in mouse serum using on-line solid-phase extraction integrated with liquid chromatography-electrospray tandem mass spectrometry. Intra-day and inter-day repeatability was 82.4-119.2 and 86.7-124.4%, respectively. The limit of detection and limit of quantification were from 0.003 to 0.288 ng/mL and from 0.009 to 0.962 ng/mL, respectively. The levels of 7 of the 10 eicosanoids-namely 8-isoPGF, PGF, PGE, 13(s)-HODE, 15(s)-HETE, 12(s)-HETE, and 5(s)-HETE-in mouse serum significantly and dose-dependently increased after arsenic exposure compared with the levels in the vehicle control group. To our knowledge, this is the first study to quantify eicosanoids in mouse serum. This approach provides simple sample preparation, small sample volumes, and a precise and accurate method for determining changes in the profile of these eicosanoids in mouse serum after acute exposure to arsenic.