Magnetic dispersive micro-solid phase extraction with the CuO/ZnO@Fe3O4-CNTs nanocomposite sorbent for the rapid pre-concentration of chlorogenic acid in the medical extract of plants, food, and water samples.

Herein, the CuO/ZnO@Fe3O4-carbon nanotubes (CNTs)-nanocomposite (NC), as a sorbent for magnetic dispersive micro-solid phase extraction, was developed for the determination of chlorogenic acid (CGA) in the medical extract of plants, food, and water samples in combination with high-performance liquid chromatography. The CuO/ZnO@Fe3O4-CNTs-NC was characterized by FESEM, EDS, XRD, TEM, BET, FT-IR, and VSM. Significant parameters (pH, temperature, eluent volume, vortex time, sonication time, CuO/ZnO@Fe3O4-CNTs-NC mass, and desorption time) that affected the extraction efficiency of CGA were optimized using Plackett-Burman as the screening design and the central composite design as the optimization strategy. Under the optimized conditions, the analytical parameters were obtained. The optimized method showed good linearity and a linear regression coefficient >0.9893. The enrichment factors ranged from 102.43 to 123.76 with the preconcentration factor of 60.0. The limits of detection (LOD) and the limits of quantification (LOQ) were 0.034-0.061 ng mL-1 and 0.114-0.202 ng mL-1, respectively. The method also reflected acceptable accuracy (from 94.07% to 109.7%) and the broad potential applications of CuO/ZnO@Fe3O4-CNTs-NC for the detection of CGA content in the medical extract of plants, food, and water samples.