Electrochemical fabrication of polypyrrole/hazelnut shells modified carbon nanocomposite sorbent for determination of polycyclic aromatic hydrocarbons using headspace solid-phase microextraction-gas chromatography

A novel composite of polypyrrole and modified activated carbon (AC) derived from hazelnut shell was electrodeposited by a chronoamperometry technique as a thin film coating on the pre-prepared stainless steel wire surface. Electrodeposition was done at ambient temperature and a fixed potential of 1 V for 1000 s. Five polycyclic aromatic hydrocarbons (PAHs) were extracted using headspace solid-phase microextraction (HS-SPME) and then detected by gas chromatography-flame ionization (GC-FID). Optimization of the extraction process was performed by the response surface methodology using the central composite design (CCD). The extraction method was optimized in terms of extraction temperature, extraction time, salt concentration, desorption temperature, and desorption time with the following results: 33°C, 45 min, 20% (W/V), 280°C, and 5 min, respectively. For the PAHs analyzed with the fiber under optimum conditions, the procedure was linear in the range of 2–200 μg/L, with detection limits of 0.1–0.5 μg/L and relative standard deviation (RSD%) of 0.2–5.4% (n = 3). Finally, the proposed method was effectively implemented to analyze PAHs in some water, tea, and vegetable samples. Flavored tea (19.0) and black tea (5.4) had the highest levels of Nap (μg/L), while Phe and Ant were not detectable in all the samples analyzed.