Dendrimer grafted nanoporous silica as a new coating for headspace solid-phase microextraction fibers

A dendrimer-like group (G1) was grafted onto Santa Barbara Amorphous-15 (SBA-15) as a nanoporous silica support to be used as a highly porous coating material for headspace solid-phase microextraction (HS-SPME) fibers. The G1-dendrimer-SBA-15 particles were characterized by N-2 sorption and thermogravimetric analyses indicating that the particles had a lengthy morphology and a specific surface area of 200 m(2) g(-1). The prepared nanomaterial was coated on a stainless steel wire for the preparation of the SPME fiber. The prepared fiber was successfully applied for the extraction of target compounds in combination with a gas chromatography-flame ionization detector. The selected extraction conditions, obtained with a simplex optimization method, were: sample volume 7.8 mL, extraction temperature 46.2 degrees C, extraction time 12.4 min, sonication time 6.4 min, pH 5.5 and salt concentration 7.2%. The repeatability for one fiber (n = 6), expressed as relative standard deviation (RSD) was between 4.6% and 6.0% and the reproducibility for five prepared fibers was between 11.0% and 12.8% for the test compounds. In comparison with commercially available PDMS/DVB fibers, the new fiber is more robust and selective, highly porous and easily and inexpensively prepared. The capabilities of the proposed method are comparable or better than those of several other methods reported in the literature.