Simple Synthesis of a Novel and Cost-Effective Fe3O4@CS@AC for Magnetic Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography with Ultraviolet Detection for the Determination of Chlorpromazine in Milk

In this study, an eco-friendly and dependable method based on magnetic solid-phase extraction and high-performance liquid chromatography equipped with ultraviolet detection was established to extract and determine chlorpromazine in milk. A novel composite material, Fe3O4@CS@AC, used as a magnetic adsorbent, was successfully synthesized via the chemical co-precipitation method and characterized. Various factors influencing the recovery of chlorpromazine were discussed and optimized. Moreover, Fe3O4@CS@AC for chlorpromazine exhibits a large adsorption capacity of 17.82 mg/g, and its mass transfer mechanism aligns more closely with the quasi-second-order kinetic model, dominated by chemisorption. Under optimal conditions, the linearity of chlorpromazine was investigated in the range of 0.01–5.00 mg/L, with a coefficient of determination greater than 0.9995, and the limit of detection was 2.47 × 10–3 mg/L. The feasibility of the developed method was evaluated by analyzing and detecting chlorpromazine in different milk samples, with recoveries of 90.76–96.72% and relative standard deviation of 2.01–4.23%. This method, with straightforward operation and good reproducibility, was successfully applied for the analysis and determination of trace chlorpromazine in milk, providing a promising avenue for the development and application of novel adsorbents in milk analysis.