Layered Double Hydroxide/Polyethylene Glycol Nanocomposite as a Solid-Phase Microextraction Fiber Coating for Pesticide Determination in Cucumber and Tomato Samples

Document Type : Original Research Paper

Authors

university of maragheh

Abstract

A novel layered double hydroxide/polyethylene glycol (LDH/PEG) nanocomposite was synthesized via a co-precipitation method and evaluated for the first time as a headspace solid-phase microextraction (HS-SPME) fiber coating for the simultaneous determination of thirteen multiclass pesticides (diazinon, fenitrothion, malathion, chlorpyrifos, penconazole, profenofos, cyproconazole, diniconazole, propiconazole, tebuconazole, fenpropathrin, phenothrin, and phosalone) in cucumber and tomato samples. The morphology and structure of the prepared SPME fiber were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Key extraction parameters including extraction temperature, sample pH, and extraction time were systematically optimized. Under the optimal conditions, the method showed linear ranges of 0.1–1000 μg L⁻¹ for chlorpyrifos and cyproconazole, and 1–1000 μg L⁻¹ for the other analytes, with coefficients of determination (R²) between 0.985 and 0.998. Limits of detection (LODs) ranged from 0.05 to 0.50 μg L⁻¹, and relative standard deviations (RSDs) at 1000 μg L⁻¹ were 3.9–8.9% (n = 3). The proposed HS-SPME method using the LDH/PEG nanocomposite fiber exhibited good analytical performance with LODs and RSDs comparable or superior to those reported in previous studies. The developed method was successfully applied to real cucumber and tomato samples with satisfactory relative recoveries.

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