Preparation of silver nanoparticles doped polyamide nanocomposite as stir bar coating for extraction of organophosphorous pesticides in water samples: modeling and optimization via central composite design

In this research a novel nanocomposite based on silver nanoparticles (Ag NPs) reinforced polyamide (PA) was prepared by in situ reduction of silver nitrate salt in PA formic acid solution[1]. The prepared nanocomposite was coated onto a stainless steel substrate by solvent exchange method to obtain a thin layer onto substrate as stir bar coating. The characterization of PA and Ag NPs/PA coated stir bars were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD) [2]. The prepared Ag NPs/PA nanocomposite-based stir bar was applied as an extraction device for stir bar sorptive extraction (SBSE) of organophosphorous pesticides (OPPs) including ethion, phosalone and chlorpyrifos in environmental water samples in combination with gas chromatography-mass spectrometry (GC-MS) [3]. The effect of silver NPs dopping level in the nanocomposite on the extraction capability of the coating was investigated. Central composite design (CCD) was employed to investigate and optimize important factors influencing the extraction and desorption processes including extraction time, salt content, pH, desorption solvent, its volume and desorption time[4]. Limit of detection (LOD) and linear dynamic range (LDR) of the method were in the range of 0.1 to 0.5 ng mL−1 and 0.3-1000 and 2-1000 ng mL-1, respectively. The method precision (RSD %) with four replicates determinations was in the range of 2.5 to 4.4 % for distilled water at the concentration level of 100 ng mL−1.