A novel hybrid mesostructured silica for the solid-phase extraction of estrogenic hormones from waters

Abstract

Mesoporous silica functionalized with octadecyl groups (denoted as SBA-15-C₁₈) was prepared and characterized. The adsorption capacity of the prepared SBA-15-C₁₈ for a mixture of twelve endocrine disrupting compounds (synthetic and natural estrogenic hormones) in aqueous media was evaluated by off-line solid-phase extraction (SPE) and compared with a commercial phase for SPE (ExtraBond® C₁₈). Analytes were determined by high performance liquid chromatography with UV-vis detection. Under optimized conditions (100 mg of SBA-15-C₁₈ sorbent; conditioning: 2 mL methanol and 2 mL Milli-Q water; loading: 150 mL water sample; washing: 5 mL Milli-Q water; elution: 2 mL methanol; flow rate 0.5 mL min⁻¹) the preconcentration factor achieved was 1000. The analytical characteristics of this methodology were evaluated, showing good precision, accuracy and linearity, with method quantification limits (MQLs) between 0.16 and 3.00 μg L⁻¹. The SBA-15-C₁₈ material enabled the extraction of the twelve estrogenic hormones in tap water (pH 6.6), mineral water (pH 5.0), groundwater (pH 7.3), river water (pH 5.0) and effluent wastewater (pH 5.0) with recoveries between 70 and 112% at the lower level studied (MQL).