Physical Vapor Deposition of Copper, Titanium and Tungsten Oxides on Glass Beads for Solid-Phase Extraction of Phthalate Esters from Bottled Water
摘要
Phthalic acid esters (PAEs) are a significant environmental and health concern due to their widespread use as endocrine-disrupting plasticizers. These compounds are commonly found in various consumer products, especially bottled water. Their potential to leach from plastic packaging into drinking water raises significant concerns about the health risks associated with exposure. This novel study introduces efficient adsorbents for solid-phase extraction (SPE) of PAEs from water. This employs physical vapor deposition (PVD) to coat glass beads (GB) with various metal oxides. Composites were compared in terms of SPE and surface characteristics. Among the various coatings tested, copper oxide (CuO) deposited for 600 s (designated as GB-CuO-600 s) proved to be the most effective, outperforming titanium dioxide (TiO₂), tungsten oxide (WO₃), and cuprous oxide (Cu₂O). The SPE method was optimized for several parameters, including the type of metal oxide, deposition time on GB, solution pH, contact time, and the dosage of the adsorbent. The optimal conditions were found to be at a pH of 6.0 with a 30-min extraction using four GB-CuO-600 s beads. The method achieved excellent preconcentration of dimethyl phthalate, diethyl phthalate, benzyl butyl phthalate, and diisobutyl phthalate, with recovery rates 69.2%-95.3%. Method validation showed good linearity, precision, and sensitivity, with detection limits between 0.005 and 0.023 mg.L⁻1. The method was successfully applied to commercial bottled water samples, confirming its practical utility with spiked recovery rates 76.8%-86.8%. Adsorption isotherm and kinetic studies indicated that the uptake of phthalates follows the Freundlich model and pseudo-second-order kinetics, primarily through physical adsorption mechanism.