Efficient extraction of atrazine in real water samples using a biopolymer ZnO@chitosan nanocomposite-based solid-phase extraction cartridge and its quantification by liquid chromatography-tandem mass spectrometry.

Atrazine, a persistent herbicide frequently detected in agricultural runoff and groundwater, requires low-cost methods for environmental monitoring and remediation. Herein, a biopolymer zinc oxide-decorated chitosan (ZnO@CS) nanocomposite was synthesized via a sol-gel method and employed as a solid-phase extraction (SPE) sorbent for atrazine removal. The as-prepared ZnO@CS nanocomposite was characterized by UV-visible spectroscopy, scanning electron microscopy (particle sizes approximately 30 to 61 nm), energy-dispersive spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and zeta-potential analysis. The as-prepared ZnO@CS-based SPE cartridge was used for the extraction recovery of the atrazine pesticide from synthetic and real water samples, and it achieved 98% atrazine recovery from synthetic water under optimized conditions of 100 µg L-1, pH 9, 25 °C, 100 min, and 100 mL. The adsorption followed pseudo-first-order kinetics (R 2 = 0.998) and fitted the Freundlich isotherm (R 2 = 0.969), consistent with adsorption on a heterogeneous surface. LC-MS/MS quantification analysis showed a linearity of R 2 = 0.992. Moreover, the as-prepared ZnO@CS-based SPE cartridge demonstrated high atrazine recovery values of up to 70% and 68% from real field water and groundwater, respectively, which are higher than that achieved with the commercial C18 cartridge (60%) for real field water. We believe that the as-prepared ZnO@CS-based nanocomposite can be a promising sorbent for atrazine extraction recovery in the future due to its cost-effectiveness, environmental friendliness, and superior extraction efficiency.