Stir bar sorptive extraction kit for determination of pesticides in water samples with chemometric data processing

Abstract

The current study describes a simple method to determine four organophosphate insecticides (i.e., ethion, phosalone, diazinon, chlorpyrifos) and an isothiazolidine acaricide (i.e., hexyhiazox), as examples of pesticides in environmental water samples by stir bar sorptive extraction (SBSE). For this purpose, a self-magnetic nanocomposite monolithic (SMNM) kit coupled with high performance liquid chromatography-ultraviolet (HPLC-UV) spectroscopy was used. The size, morphology, and elemental distribution of synthesized SMNM kit were analyzed using field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray (EDX) spectroscopy system, X-ray diffraction (XRD), and elemental mapping, respectively. An experimental design based on the central composite design (CCD) was used to optimize factors affecting SBSE. Under optimal experimental conditions, the limits of detection (LODs) were found to be in the range of 0.07 μg L−1 to 0.89 μg L−1. Linear ranges were 5-800 μg L−1 for ethion, hexythiazox, and chlorpyrifos, 1–1000 μg L−1 for phosalone, and 5–1000 μg L−1 for diazinon. The relative standard deviation (RSD%) did not exceed 5.48% and 6.45% for intraday and interday precisions, respectively. The enrichment factors (EFs) ranged from 15 to 39-fold (theoretical enrichment factor was 40-fold). The results showed that SMNM kit could enrich the above-mentioned pesticides effectively. The SMNMSBSE-HPLC-UV methodology was applied for the determination of pesticides in real water samples.