Introduction of coiled SPME coated by mesoporous silica/CTAB as a novel and highly efficient fiber for environmental analysis

In this study, a tiny coiled cupper wire as a novel solid phase microextraction (SPME) fiber was coated with mesoporous silica/cetyltrimethylammonium bromide (MCM-41/CTAB) as an adsorbent by Electrochemically Assisted Self Assembly (EASA) method [1] and used for the analysis of poly cyclic aromatic hydrocarbons (PAHs) as model analyets. For the first time a high efficiently form of SPME fibers named coiled SPME (C-SPME) was evaluated for sampling, clean up and preconcentration of various analytes (drugs, PAHs and insecticide) with chromatographic method.Deposition of MCM-41/CTAB resulted in easily controlled and reproducible SPME coatings with inherent characteristics such as biocompatibility, thermal stability and porous structure. Non calcined MCM-41/CTAB on C-SPME plays a key role in adsorption of PAHs with more extraction efficiencies and enrichment factor than commercially available SPME fibers. C-SPME procedure followed by desorption in acetonitrile and after the certain period of time acetonitrile was removed with a gentle N2 stream. Finally the residue analytes was redissolved in 50 µL acetonitrile and injected into the HPLC-UV. The parameters affecting the extraction efficiency such as PH, adsorption and desorption time, salt addition, type of desorption solvents and etc. were optimized. Under the optimum conditions low detection limits (36-1220 pg L-1), and wide linear dynamic ranges (R2 0.98) were achieved in the range of 0.25-25000, 0.12-15000, 0.56-132000, 4.1-100000 ngL-1 for phenanthrene, anthracene, fluoranthene and pyrene respectively. Extraction recoveries (ERs) and the relative standard deviations for intra-day and inter-day variations (n=5) were in the range of 36%-85%, 2.3-5.8 and 1.3-4.8 respectively. The proposed method was successfully applied for determination of PAHs in different samples such as soil, well water and surface water with satisfactory recoveries of 76 – 110 %.