Application of magnetic AlFu MOF nanocomposite for the extraction and preconcentration of some pesticides from different distillates

Abstract

This research used a magnetic AlFu nano-metal-organic framework as an adsorbent for the first time. This approach extracts and preconcentrates eight pesticides from various distillates through a two-step process: magnetic dispersive micro solid phase extraction and dispersive liquid-liquid microextraction. Initially, the nanocomposite is dispersed into a sample solution containing the pesticides and Na₂SO₄. The target pesticides are then adsorbed onto the nanocomposite, which is subsequently isolated from the aqueous phase using an external magnetic field. Acetonitrile is used to elute the adsorbed analytes pesticides from the nanocomposite surface. The resulting acetonitrile extract, containing the concentrated pesticides, is then mixed with a tiny amount of another solvent and injected into a NaCl solution. Centrifugation allows the organic phase, enriched with the pesticides, to settle down. An aliquot of this organic layer is then analyzed using a gas chromatography-flame ionization detector. Optimization of the procedure led to favorable performance, including good extraction recovery of the pesticides (68–98 %), significant enrichment (enrichment factors of 340–489), a wide range of detectable concentrations (2.90–1400 µg L⁻¹), and low detection (0.15–0.88 µg L⁻¹) and quantification limits. (0.49–2.90 µg L⁻¹)