Solid Phase Extraction of Zearalenone (ZEN) from Beer Samples Using Natural Zeolite Clinoptilolite and Organo-Zeolites Prior to HPLC Determination

Abstract

Zearalenone (ZEN), is a secondary metabolite with estrogenic properties, is produced by several Fusarium species that colonize cereal grains such as corn, oats, barley, wheat, and grain sorghum in the field and in storage. Because of the toxic effects of ZEN which cause significant human and animal diseases and significant economic losses worldwide, its removal from food samples is very important. In this study, the applicability of natural zeolite, Clinoptilolite (CLN), and organo-clinoptilolites modified with the quaternary ammonium salts tetramethylammonium bromide (TMA) for the short-chain organo-zeolite and octadecyl trimethyl ammonium bromide (ODTMA) for the long-chain organo-zeolite, has been investigated for the adsorption and preconcentration of Zearalenone (ZEN) from beer solutions. In the batch experiments, ZEN was quantitatively adsorbed (~100%) at the pH range of 1.1–9.0 by ODTMAClinoptilolite (ODTMA-CLN). As for CLN and TMA-Clinoptilolite (TMA-CLN), ZEN adsorptions were about 100% at the pH range 1.1-4.5 and 70% at pH range 4.8-7.0. The adsorption of ZEN was investigated in terms of the Langmuir and Freundlich isotherm models and the Freundlich isotherm model was found as being adequate to describe the adsorption for all adsorbents. The proposed methodology was applied to the beer samples for adsorption and preconcentration of ZEN, the recoveries found for CLN and TMA-CLN were not sufficient (44.0 and 56.7%, respectively), but the recovery carried out with ODTMA-CLN was high (89.5%).