Determination of residual bendiocarb in environmental samples using magnetic nanoparticles modified with cetyldimethylbenzylammonium chloride by UV-Vis spectrophotometry

Bendiocarb (BEN), a highly toxic carbamate insecticide used in agriculture, is effective against various nuisance and disease vector insects. Utilizing Fe3O4 magnetic nanoparticles coated with cetyldimethylbenzylammonium chloride (CDMC), a simple and sensitive solid-phase microextraction technique has been devised for the preconcentration and determination of BEN at trace levels in environmental samples. Fe3O4@CDMC nanoparticles (NPs) were utilised as the magnetic solid-phase extraction agents. The azo-dye produced between BEN and the diazotised procaine benzylpenicillin (drug compound) adsorbed on the NPs was eluted using ethanol and quantified spectrophotometrically at wavelength 456 nm. Experimental factors impacting the extraction efficiency of the method were optimised: the amount of surfactant (1 mg) and the sorbent (30 mg), type and volume of base (sodium hydroxide, 2 mL), type and volume of eluent (ethanol, 1 mL), and extraction time (15 min). The relative standard deviation (RSD%) of the method was investigated and it ranged from 1.8–4.2% (n = 5). Upon optimisation, BEN could be concentrated from different samples 50-fold with an enrichment factor of 72. The linear range, correlation coefficient (R) and detection limit could reach 0.03–1.5 µg/mL, 0.9984 and 0.01 µg/mL, respectively. The technique has been effectively verified for detecting bendiocarb in various environmental samples.