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Abstract
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A novel nanocomposite based on reinforcing of multiwalled carbon nanotubes in polyamide (PA)
was prepared by solvent exchange method as stir bar coating. The morphology and surface characteristic
of PA and CNT/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 of bisphenol A from aqueous samples followed by high performance liquid
chromatography-UV detection. The effect of CNTs doping level and oxidation of CNTs on the
extraction capability of the coating was investigated. Response surface methodology applying
central composite design was used for modeling and optimization of important factors influencing
the extraction and desorption processes including extraction time, salt and methanol content,
desorption solvent, its volume and desorption time. Limit of detection and linear dynamic range
of the method were 0.3 ng mL−1 and 1–10 ng mL−1, respectively. The method precision (RSD%)
with four replicate determinations was 4.9% for distilled water at the concentration level of
10 ng mL−1. The obtained RSD% for reproducibility of stir bars was 7.4%. The developed method
was successfully applied to the bottled mineral water samples, while the relative recoveries (RR%)
were obtained to be in the range of 92.0–101.9%.
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