Development of solid phase micro-extraction method based on nano ZnO and multi-walled carbon nanotube composite for extraction and measurement of some polycyclic aromatic hydrocarbons in tobacco

With the expansion Polycyclic Aromatic Hydrocarbons (PAHs), the contamination of food with these pollutants has become a health threat all over the world in such a way that many regulatory authorities have set permissible limits for them. Today, the measurement of these pollutants in food is one of the important research fields. In this research, ZnO/MWCNTs nanocomposite coating was fabricated on stainless steel and investigated as a new upper space solid phase microextraction (HS-SPME) fiber coating for extracting small amounts of environmental pollutants. The characteristics of the prepared nanocomposite were evaluated using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The parameters affecting the HS-SPME of hydrocarbons (for example, extraction temperature, extraction time, desorption temperature, desorption time, and salt concentration) were investigated and optimized using the method of one variable at a time. The coating was used to measure 4 PAHs including naphthalene, fluorene, anthracene and phenanthrene in hookah water samples obtained from different tobaccos. The results show that the prepared nanocomposite can be a promising coating material for future applications of SPME and related sample preparation techniques. This method was linear in the concentration range of 1 to 20 μg/liter for the 4 PAHs, and the RSD% of the method was less than 9%, and the LOQ were generally around 0.3 μg/liter.