Quantification of urinary F2-isoprostanes with 4(RS)-F4t-neuroprostane as an internal standard using gas chromatography–mass spectrometry: Application to polytraumatized patients

Isoprostanes are a family of prostaglandin isomers produced from oxidation of polyunsaturated fatty acids through a non-enzymatic free radical-catalyzed mechanism. Quantification of F2-isoprostanes (F2-IsoPs) provides a good index of oxidative stress and allows non-invasive assessment of lipid peroxidation in vivo. Since “interferences peaks” at m/z 573 co-elute with d4-15-F2t-IsoP preferentially used, we propose a new GC–NICI-MS approach to quantify urinary F2-IsoPs by using 4(RS)-F4t-neuroprostane as the internal standard. This method was applied to quantify urinary F2-IsoPs excretion in healthy volunteers and polytraumatized patients. Our results showed a significant increase (p < 0.0001) in urinary F2-IsoPs in polytraumatized patients compared with healthy volunteers (4.73 ± 2.75 ng/mg vs. 0.811 ± 0.359 ng/mg creatinine).