مشخصات پژوهش

Graphene and graphene oxide (GO) has remarkable properties, such as huge surface area good chemical stability, and graphitized basal plane structure, which allow it to have strong t in many molecules[1,2]. Therefore it can be considered as an efficient sorbent in sample preparation purposes. In this study a new simple method based on solvent exchange method was developed to prepare GO/polyamide nanocomposite (GO/PA) coated stir bar. Polyamide was applied as nanocomposite bulk polymer due to its polar nature and feasibility of coating methods of nanocomposite on stir bar substrate. The morphology and surface characteristic of PA and GO/PA coated stir bars were investigated using scanning electron microscopy (SEM). The stir bar coated by GO/PA nanocomposite was used as an extraction device for stir bar sorptive extraction3 (SBSE) of organophosphorous pesticides in aqueous samples followed by gas chromatography-flame ionization detector (GC-FID) detection. The effect of GO doping level on the extraction capability of the coating was investigated. Important factors influencing the extraction and desorption processes including extraction time, salt content, sample volume, pH desorption solvent, its volume and desorption time were studied and optimized using response surface methodology (RSM) applying central composite design (CCD).