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Abstract
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A novel method for preparation of stir bar coating based on various nanocomposites is introduced. In this method, nanocomposites are easily coated on a stainless steel substrate using solvent exchange method. The solvent exchange method is based on a phenomenon that a solid polymer film forms at the interface between an aqueous solution and a solution of a water-insoluble polymer upon their contact [1]. In this procedure the nanofiller was dispersed in a polymeric solution, the substrate was immersed in this solution and after deposition of a layer of polymeric solution on it, it is immersed in water which leads to the formation of a nanocomposite layer coated on a substrate. Various nanocomposites coated stir bars can be prepared using this procedure concerning the different polymeric matrix and different nanofillers in order to sorptive extraction [2] of different analytes with different polarity. In this regards, the nanocomposites based on reinforcing of multiwalled carbon nanotubes (MWCNTs) and graphene oxide (GO) in polyamide (PA) were prepared as stir bar coating. The morphology and surface characteristic of PA, CNT/PA and GO/PA coated stir bars were investigated using scanning electron microscopy. The stir bar coated by CNT/PA nanocomposite 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 [3]. Additionally it was applied to SBSE of naproxen from biological samples followed by spectrofluorimetric determination [4]. The GO/PA coated stir bar was applied to extraction of tramadol from biological samples followed by spectrofluorimetric detection. Important factors influencing the extraction and desorption processes were studied and optimized using response surface methodology applying central composite design. In order to evaluate the developed methods, Limits of detection, the methods precision, the linearity of the meth
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