Amino-silica/graphene oxide nanocomposite coated cotton as an efficient sorbent for needle trap device.

Cotton and silica are easily available and plentiful natural materials, with significant sorptive properties, which can be provided easily at low prices. In this research, a novel and effective sorbent was synthesized by covalent attachment of amino-silica/graphene oxide nanocomposite to the cotton (Cot/GO/Si) and packed into a stainless steel needle for preparation a needle trap device (NTD). The nanocomposite sorbent was characterized by SEM and FT-IR. The Cot/GO/Si packed NTD was used for direct extraction of PAHs from polluted soil samples, followed by GC-FID measurement. Different affecting experimental variables, including extraction temperature, flow rate, desorption time and temperature were studied and optimized. Under the optimal conditions, good linearity of the calibration curves (R2  > 0.99) was obtained over the concentration range of 0.01-1.0 μg g-1 . The limits of detection, limits of quantification and relative standard deviations were found to be in the ranges of 0.05-0.17 ng g-1 , 0.2-0.6 ng g-1 and 9.7-15.4% (n = 6), respectively. Finally, the proposed NTD-GC-FID method was successfully applied for the extraction and determination of PAHs in contaminated soil samples.