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Abstract
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In this research a novel sorbent based on reinforcement of montmorillonite (MMT) [1,2]
into polypyrrole-polyamide (PPy-PA) hybrid was fabricated by in situ oxidative
polymerization of polypyrrole into MMT/PA mixture. The prepared nanocomposite was
coated onto stainless steel substrate by solvent exchange method to form a thin layer of
nanocomposite. The PA and MMT/PPy/PA coated stir bars were characterized using scanning
electron microscopy (SEM), energy dispersive X-ray spectroscomy (EDX), X-ray diffraction
(XRD) and Fourier transform infrared sepectroscopy (FTIR). The prepared MMT/PPy/PA
nanocomposite-based stir bar was applied as an extraction device for stir bar sorptive
extraction (SBSE) of organophosphorous pesticides (OPPs) as model compounds including
chlorpyrifos, ethion and phosalone in river water samples in combination with gas
chromatography-flame ionization detector (GC-FID) detection. The effect of MMT amount in
the nanocomposite and also the effect of PPy incorporation into PA on the extraction
capability of the coating were investigated. Accordingly, the 15 % MMT doping level has led
to higher extraction capability. Furthermore, it was found that PPy hybridation into
nanocomposite has significant effect in improving the extraction capability of the coating.
Important factors influencing the extraction and desorption processes including extraction
time, salt content, pH, desorption solvent, its volume and desorption time were studied and
optimized using response surface methodology (RSM) applying central composite design
(CCD) [4]. The developed method was successfully applied to determine selected OPP
compounds in two river water samples and high relative recovery percentages were resulted.
References
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