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This paper reports an online SPE-LC-MS/MS method for the simultaneous quantification of prostaglandins (PGE 2 and PGF 2α ) in menstrual fluid samples. To meet this goal human peripheral serum was used as surrogate matrix. The analytes were trapped on an OASIS HLB cartridge for 3 min, for sample cleanup and enrichment, and then transferred during only 42 s to an HSS T3 C18 analytical column, for separation and analysis. Prostaglandins (PGs) were detected by selected reaction monitoring in negative ion mode, PGE 2 (m/z 351 → 315) and PGF 2α (m/z 353 → 193) using isotope-labeled internal standard (PGE 2 -d 4 , m/z 355 → 319). The concentration linear range was of 10.34-1.034 ng mL -1 and the lower limit of quantification (LLOQ) was 10.34 ng mL -1 for both PGs. Validation parameters were successfully assessed according to the European Medicines Agency guideline (EMA), also comprising the FDA normative. The method showed no matrix effect and process efficiency around 100%, in addition to only 15 min of analysis time with lower solvent consumption. The method application was carried out using two menstrual fluid sample groups: control (n = 15) and treatment group (n = 7; samples from women that used Tahiti lemon juice). The PGF 2α levels were found to be higher in treated group than in control group (p ≤ 0.05), denoting an effect of the intake of Tahiti lemon juice on the menstrual inflammatory process. The on-line method herein reported could be useful for the analysis of PGs from large research studies., (Copyright © 2019 Elsevier B.V. All rights reserved.)

There is a clinical need for more relevant coverage of bioactive lipids using smaller sample volumes. Therefore, we have validated a tandem mass spectrometry method for combined solid phase extraction of 37 compounds in the oxylipin (OxL) and 14 in the endocannabinoid (eCB) metabolome, as well as prostamides. The limits of quantification (LOQ) for compounds in the eCB metabolome were in the range 0.5-1000 fg on column, intraday accuracy and precision ranges (%) were 83-125 and 0.3-17, respectively, and interday accuracy and precision ranges (%) were 80-119 and 1.2-20, respectively, dependent upon the compound and the concentration studied. Corresponding values for OxL were 0.5 fg-4.2 pg on column (LOQ), 85-115% (inter- and intraday accuracy) and <5% (precision). The combined extraction method was successfully applied to tissues, cell extracts, human plasma and milk samples. A deeper study of levels in elk, pig and cow brain, as well as cow heart and liver revealed tissue and species-specific elevation of eicosanoids: arachidonate diols, 20-HETE and 12(S)-HEPE (cow liver), LTB4 (cow brain), and monohydroxy metabolites (HETEs), epoxides and 5-oxo-ETE in elk brain, which might be caused by factors of stress and/or post-mortem reactions in the tissues., (Copyright © 2015 Elsevier Inc. All rights reserved.)