Analytical Methodology for Trace Determination of Propoxur and Fenitrothion Pesticide Residues by Decanoic Acid Modified Magnetic Nanoparticles

A sensitive, rapid, reliable, and easily applicable method based on magnetic solid phase microextraction (MSPE) combined with HPLC-PDA was developed for monitoring Propoxur (PRO) and Fenintrothion (FNT) pesticides in environmental water samples. The effect of major experimental variables on the extraction efficiency of both the pesticides was investigated and optimized systematically. For this purpose, a magnetic material including decanoic acid on surface of particles was synhtezied and characterizied by XRD, FT-IR, SEM, EDX and TGA analysis in detail. The simultaneous determination of pesticide molecules was carried out by using Luna Omega C18 column, isocratic elution of acetonitrile (ACN):water (70:30 v/v) with a flow rate of 1.2 mL min−1. After MSPE, the linear range for pesticide molecules (r2 > 0.9982) was obtained in the range of 5–800 ng mL−1 and 10–800 ng mL−1, respectively. The limit of detections (LOD) are 1.43 and 4.71 ng mL-1 for PRO and FTN, respectively while RSDs % are below than 3.5 %. The applicability of the proposed method in four different environmental samples were also investigated using standard addition-recovery procedure. Average recoveries at two spiking levels were over the range of 91.3–102.5% with RSD < 5.0% (n = 3). The obtained results show that decanoic acid grafted magnetic particles in MSPE combined with HPLC-PDA is a fast and simple method for the determination of PRO and FNT in real samples.