Simplified solid-phase extraction for measurement of F2-isoprostanes in human plasma and urine

Abstract

Several methods for measuring F2-isoprostanes have been established in recent years, namely GC-MS [1], LC-MS [2], EIA [3], RIA [4]. Although quantitative methods by chromatography have been developed, further improvements are still required to reduce the number of steps for sample preparation. Most sample preparation for chromatographic analysis involves solid-phase extraction (SPE) followed by a further purification by TLC or HPLC. In this study, the authors were able to establish a rapid one-step method by preparing the samples by anion exchange SPE, which is highly selective for acidic compounds. Hydrolyzed plasma and urine samples of healthy individuals were acidified before SPE. The eluted samples were first derivatized with pentafluorobenzyl bromide followed by a second derivatization with bis-(trimethylsiyl)trifluoroacetamide. F2-isoprostanes were analyzed by GC–MSD–NCI. Our data showed that anion exchange SPE prior to GC–MSD–NCI analysis for determining F2-isoprostane in biological fluids is robust, time saving and less laborious in comparison to other methods reported.