Preparation and characterization of aptamer-based sorbent for the selective extraction of zearalenone and its derivatives from human urine.

The aim of this work is the development of a biomimetic strategy involving a molecular recognition mechanism using aptamers immobilized on a solid support for the analysis of the mycotoxin zearalenone (ZEA) and two of its derivatives in human urine: alpha-zearelenol (α-ZEL) and beta-zearelenol (β-ZEL). Three oligonucleotide sequences reported in the literature as being specific to ZEA were thus covalently grafted onto activated sepharose, and a thorough study of the percolation and washing conditions was performed to promote the selective retention of the three targeted compounds. With the optimized extraction procedure, a strong and selective retention was obtained for ZEA and to a lesser extent α-ZEL and β-ZEL, with extraction recoveries of 88±9%, 77±15%, and 45±12% respectively, in standard solutions. Application of this procedure to spiked human urine strongly highlighted the efficiency of the clean-up effect resulting from the use of this selective sorbent. Limits of quantification of the whole analytical procedure including extraction on oligosorbent and LC-MS analysis were 0.18 and 0.24 ng mL, for ZEA and α-ZEL, respectively, thus demonstrating clearly the potential of the developed method for monitoring human dietary exposure to these compounds.