Nitrogen-Doped Graphene as an Efficient Sorbent for Needle Trap Device

Less oxygen-containing functional groups in reduced graphene-oxide (RGO) compared to GO, increases the percentage of G-band (sp۲ carbon network), which leads to an increase in its affinity toward aromatic compounds, particularly polycyclic aromatic hydrocarbons (PAHs). This effect is significantly improved by doping RGO with nitrogen atoms, resulted in an increase in its adsorption capacity to PAHs. Herein, nitrogen modified reduced graphene oxide (N-RGO) was synthesized through a hydrothermal method and packed into a stainless-steel needle for preparation a needle trap device (NTD). The nanocomposite sorbent was characterized by SEM۲and FT-IR spectrometry. The N-RGO packed NTD was used for the extraction of PAHs from polluted soil samples, followed by GC-FID measurement. Different affecting experimental variables, including extraction temperature, flow rate, desorption time and desorption temperature were studied and optimized using a multivariate optimization design. Under the optimal conditions, the calibration graphs showed good linearities (R۲ > ۰.۹۹) over the concentration range of ۰.۰۱-۱.۰ μg g-۱ for naphthalene, ۰.۰۵-۱ μg g-۱ for phenanthrene, ۰.۰۲-۱ μg g-۱ for acenaphthene , ۰.۰۴-۱ μg g-۱ for fluoranthene, and ۰.۰۱-۱ μg g-۱ for pyrene. The limits of detection, limits of quantification and relative standard deviations were found to be in the ranges of ۰.۰۵-۰.۱۷ ng g−۱, ۰.۲-۰.۶ ng g-۱ and ۹.۷-۱۵.۴% (n=۶), respectively. Finally, the proposed NTD-GC-FID method was successfully applied for the extraction and determination of PAHs in contaminated soil samples.

کلیدواژه ها:

Nitrogen-Doped Graphene ، Needle Trap Device ، PAHs ، GC-FID