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Abstract
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In the present work, a novel nanocomposite (NC) was prepared by
reinforcing montmorillonite (MMT) into polypyrrole-nylon-6 (PPy-
N6) hybrid through in situ oxidative polymerisation of PPy in the
MMT-N6 mixture. The prepared novel NC was deposited as a thin
layer coating on the stir bar substrate by solvent exchange
method. Fourier transform infrared spectroscopy, scanning electron
microscopy, X-ray diffraction and energy dispersive X-ray
spectroscopy were applied to characterise the prepared NCs. The
prepared stir bar based on MMT/PPy/N6 NC was applied for
sorptive extraction of some organophosphorous pesticides
(OPPs) in river water samples with detection by gas chromatography-
mass spectrometry (GC-MS). The effect of MMT doping level in
the NC and also the effect of PPy hybridation with N6 on the
coating extraction capability were studied. Central composite
design was used to optimise and study the effects of influencing
factors on the stir bar sorptive extraction efficiency such as salt
content, pH, extraction time, desorption time, desorption solvent
and its volume. The method optimisation step was performed
using gas chromatography-flame ionisation detector, while the
method validation was conducted using GC-MS. Limits of detection
of the developed method are in the range of 0.05–0.3 μg L−1
and the linear dynamic ranges are in the range of 0.3–1000 and
1–1000 μg L−1, respectively. The intra-day precision (RSD %) of
developed method with four replicates varied between 5.4 and
8.2% for distilled water spiked at 100 μg L−1. The applicability of
the developed method was examined by extraction and determination
of OPP compounds in river water samples, indicating the
relative recoveries in the range of 80.3–95.3%.
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