Polymeric and silica sorbents on endocrine disruptors determination

Abstract

Endocrine disrupting determination at low concentration levels comprises one of the most important targets in environmental analytical chemistry. In spite of inherent high sensitivities obtained for HPLC, these techniques have some limitations depending on the contaminants. As a result, interest in preconcentration using solid-phase extraction (SPE) still continues increasingly for endocrine disrupting determinations by HPLC due to the high accuracy of this method. In this work, we evaluated three different adsorbents in preconcentration of endocrine disruptors in three different categories: pharmaceuticals (sulphamethoxazole, trimethoprim and diclofenac), hormones (estrone, 17β-estradiolacetate and 17β-estradiol) and plastic materials (bisphenol A) in multicomponent aqueous solution using the combination SPE-HPLC. The adsorbents investigated were modified silica (octadecylsilane)—DSC-18 (Supelco) and two polymers, a divinylbenzene-N-vinilpirolidona—Oasis® HLB (Waters) and a styrene-divinylbenzene modified with butyrolactone—Strata-X™ (Phenomenex). The parameters selected to evaluate the best adsorbent were sample loaded, breakthrough volume, recovery and adsorption capacity. The results showed that the polymeric sorbents Oasis and Strata presented good separation and selective ability; therefore, the most efficient sorbent for the described test was applied to the determination of endocrine disruptors (ED) in a real wastewater sample. Almost all endocrine disruptors studied in the present work were found and quantified in the effluent sample, suggesting that the selected cartridge could be useful for the preconcentration of endocrine disruptors in environmental analytical applications. Correlation analysis identified the adsorption parameters that had the greatest influence on the efficiency of SPE adsorbents, such as initial ED concentration, breakthrough volume and recovery.