Dried blood spot (DBS) sample collection for determination of the oxidative stress biomarker 8-epi-PGF2a in humans using liquid chromatography/tandem mass spectrometry

RATIONALE: F2-isoprostanes are a series of prostaglandin F2-like compounds that are formed by free-radical-catalyzed peroxidation of arachidonic acid (ARA). Several F2-isoprostanes, but in particular 8-epi-PGF(2 alpha), are widely used as oxidative stress biomarkers. In this study we have developed an analytical tool for finger-tip blood sampling and analysis of 8-epi-PGF(2 alpha) from dried blood spots (DBS). METHODS: We have applied solid-phase extraction (SPE) and liquid chromatography/tandem mass spectrometry (LC/MS/ MS) for the extraction, separation and detection of 8-epi-PGF(2 alpha) in DBS and have studied the stability of this marker using the DBS collection platform. RESULTS: The mass limit of detection (mLOD) for 8-epi-PGF(2 alpha) extracted from DBS samples was 1.5 pg while the concentration limit of detection (cLOD) and concentration limit of quantitation (cLOQ) were 6 pg/mL and 18 pg/mL, respectively. All values based on triplicate analysis. Sufficient stability of 8-epi-PGF(2 alpha) in DBS was achieved by preconditioning DBS paper with vitamin E and BHT. CONCLUSIONS: The developed method is sensitive, specific, robust, efficient, and can accurately measure endogenous concentrations of 8-epi-PGF2a in DBS. Thus, it offers an analytical approach to measure 8-epi-PGF2a by a novel sample collection technique that is less invasive and costly than conventional techniques. Copyright (C) 2012 John Wiley & Sons, Ltd.