Rapid extraction and determination of Diazinon using agarose-coated iron oxide magnetic nanoparticles modified with a naphthohydrazine derivative via magnetic solid-phase extraction technique before GC-MS analysis

In this study, diazinon, as a widely used organophosphate pesticide, is critical for environmental and public health monitoring at extreme levels. Agarose magnetic nanoparticles were investigated as a novel adsorbent for the extraction and preconcentration of diazinon from aqueous samples. The effective parameters, including pH, adsorbent amount, ionic strength (IS), sample volume, and time, were systematically optimized. Also, the MSPE (magnetic solid-phase extraction) technique demonstrated significant advantages, including high speed, reduced solvent requirements, and ease of use. The synthesized adsorbent, under optimized conditions, demonstrates high extraction efficiency for diazinon across various real samples, as determined by gas chromatography-mass spectrometry (GC-MS). The limit of detection (LOD) and limit of quantification (LOQ) for diazinon were 0.08 µg L-1 and 0.24 µg L-1, respectively, indicating the high sensitivity of the developed method. A linear range and correlation coefficient (R²) of diazinon were obtained in the concentration range of 0.25–16.0 µg L-1, with a value of 0.992, respectively (%RSD<5). As a result, agarose magnetic nanoparticles have great potential for use in the extraction and preconcentration of pollutants, serving as efficient, recyclable adsorbents. This method can also be used to analyze other organic contaminants in environmental and food samples.