ZnO nanoparticles doped polyamide nanocomposite coated on cellulose paper as a novel sorbent for ultrasound-assisted thin film microextraction of organophosphorous pesticides in aqueous samples

Abstract

In this work, a novel thin film based on ZnO nanoparticles (ZnO NPs) incorporated into polyamide (PA) has been designed and prepared. For this purpose, the ex situ prepared ZnO NPs were dispersed into PA solution and the obtained solvent blend was deposited onto cellulose paper applying a solvent exchange method. The characterization of the prepared ZnO NPs/PA nanocomposite was performed applying energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The prepared thin film based on ZnO NPs/PA/cellulose paper was employed for ultrasound assisted thin film microextraction (USA-TFME) of some organophosphorous pesticides (OPPs) as model compounds including fenthion, chlorpyrifos, fenithrothion, phosalone, edifenphos and ethion in environmental water samples followed by gas chromatography-flame ionization detection (GC-FID) determination. The effect of the level of ZnO NP doping into the prepared nanocomposite on the extraction efficiency of the thin film was studied. The important parameters influencing the extraction and back-extraction steps of USA-TFME were optimized by applying a Taguchi orthogonal array design. The limits of detection (LODs) for the developed method were in the range of 0.05 to 0.3 ng mL⁻¹ and its linear dynamic ranges (LDRs) were 0.2–1000, 0.3–1000 and 1–1000 ng mL⁻¹ for different analytes. The method precision (RSD%) with three replicates was in the range of 2.1 to 9.8% using spiked distilled water (100 ng mL⁻¹).