Amino ethyl-functionalized nanoporous silica as a novel fiber coating for solid-phase microextraction.

Nanoporous silica (SBA-15) was prepared and functionalized with 3-[Bis(2-hydroxyethyl)amino] propyl-triethoxysilane (HPTES) to be used as a highly porous fiber coating material for solid-phase microextraction (SPME). The prepared HPTES-SBA-15 particles had a lengthy morphology and a specific surface area of 790 m(2) g(-1). They were characterized by N(2) sorption analyses, scanning electron microscopy and thermogravimetric analysis. The prepared nanomaterial was immobilized onto a copper wire for fabrication of the SPME fiber. The fiber was evaluated for the extraction of BTEX and some phenolic compounds in combination with GC-MS. For optimization of factors affecting the extraction efficiency of the phenolic compounds, a simplex optimization method was used. The proposed fiber showed some selectivity towards the polar phenolic compounds with extraction efficiencies better than a PDMS commercial fiber. The repeatability for one fiber (n=5), expressed as relative standard deviation (RSD), was between 6.5% and 9.8% and the reproducibility for five prepared fibers was between 8.2% and 11.3% for the test compounds. No significant change was observed in the extraction efficiency of the new SPME fiber over 50 extractions. The fiber was successfully applied to the determination of phenolic compounds in spiked river water and sewage samples. Thus, HPTES-SBA-15 fiber is a promising alternative to the commercial fibers as it is robust, selective, highly porous and easily and inexpensively prepared.