مشخصات پژوهش

A novel nanocomposite based on incorporation of multiwalled carbon nanotubes (MWCNTs) in polyamide (PA) was prepared as stir bar coating. Proposed nanocomposite was coated on stainless steel substrate by solvent exchange method. The surface characteristic of PA and CNT/PA coated stir bars was investigated using scanning electron microscopy (SEM). The prepared CNT/PA nanocomposite-based stir bar was used as an extraction device for stir bar sorptive extraction (SBSE) of bisphenol A from aquatic environment followed by high pressure liquid chromatography-UV-Vis (HPLC-UV-Vis) detection. The effect of CNTs doping level and oxidation of CNTs on the extraction capability of coating was investigated. Important parameters influencing the extraction and desorption processes including extraction time, salt and methanol content, desorption solvent, its volume and desorption time were optimized using response surface methodology (RSM) applying central composite design (CCD). Limit of detection (LOD) was 0.3 ng mL−1 and the method precision (RSD %) with four replicates was 4.9 % for distilled water at the concentration level of 10 ng mL−1. The linearity of the method was 1–100 ng mL-1. The reproducibility of the presented method was evaluated by preparing five identical stir bars using a unit solvent and performing five extractions from the aqueous solution applying different stir bars under the same extraction and desorption conditions. The obtained RSD% was 7.4%. .