And Functionalized With 3-aminopropyltriethoxysilane Research Articles

A Hexagonally Ordered Nanoporous Silica-Based Fiber Coating for SPME of Polycyclic Aromatic Hydrocarbons from Water Followed by GC–MS

A highly porous fiber coating material was prepared and functionalized with 3-amino propyl triethoxysilane (APTES) on hexagonally ordered nanoporous silica (SBA-15). Applicability of this coating was assessed employing a laboratory made solid-phase microextraction (SPME) device and gas chromatography–mass spectrometry for the simultaneous sampling and determination of trace polycyclic aromatic hydrocarbons (PAHs) from aqueous sample solutions. A one at the time optimization strategy was applied to investigate and optimize important extraction parameters such as extraction temperature, extraction time, ionic strength and sonication time. In the optimum conditions, the relative standard deviations for deionized water, spiked with selected PAHs were between 3.3 and 7.7% (n = 3), and detection limits for the studied compounds were 4.2 and 26.1 pg mL−1. No significant change was observed in the extraction efficiency of the new SPME fiber, over 50 extractions. The proposed method was successfully applied to the extraction and determination of PAHs in the waste water samples.

Cu(II) complexes imobilized on functionalized mesoporous silica as catalysts for biomimetic oxidations

Mesoporous HMS silica was synthesized and functionalized with 3-aminopropyl-triethoxysilane (APTES) by a post-synthesis method. HMS and NH2-HMS supports were used for immobilization of two Cu(II) biomimetic complexes ([Cu(acac)(phen)(H2O)](ClO4), [Cu(acac)(Me2bipy)](ClO4)) or laccase enzyme. Mesoporous structure of the support; functionalization of silica surface, structure of ligands, and Cu complexes; and their immobilization were evidenced by XRD analysis, N2 adsorption–desorption, SEM microscopy, TGA-DTA, IR and UV–Vis spectroscopy, and elemental analysis. The results confirm the structural integrity of the mesoporous hosts and successful anchoring of the metal complexes over the supports. For comparison, copper-substituted mesoporous silica (Cu-HMS) by using dodecylamine as structure-directing agent was also synthesized. All the synthesized materials were tested for their catalytic activity on the oxidation of 4-aminoantipyridine, 2,2′-azinobis (3-ethyl-benzothiazoline)-sulfonic acid (ABTS) with air, as well as in liquid phase oxidation of anisole and phenol with hydrogen peroxide. In order to verify the complex biomimetic activity, the Trametes versicolor laccase was immobilized by adsorption in the same supports.