Development of a simple, highly selective, and sensitive analytical method for phthalate monoesters (mPAEs) remains a challenge due to the complexity of biological samples. To address this issue, Cu²⁺ immobilized magnetic covalent organic frameworks (Fe₃O₄@TtDt@Cu²⁺ composites) with core-shell structures were prepared to enhance the enrichment efficiency of mPAEs by a facile approach synthesis of COFs shells with inherent bifunctional groups on Fe₃O₄ NPs and further Cu²⁺ immobilization. The composites exhibit high specific surface area (348.1 m² g⁻¹), outstanding saturation magnetization (34.94 emu g⁻¹), ordered mesoporous structure, Cu²⁺ immobilization, and excellent thermal stability. Accordingly, a magnetic solid-phase extraction (MSPE) pretreatment technique based on Cu²⁺ immobilized COF composites combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established, and key parameters including the adsorbent amount, adsorption time, elution solvent, etc. were examined in detail. The developed analytical method showed wide linear ranges (10–8000 ng L⁻¹), low limit of detections (LODs, 2–10 ng L⁻¹), and good correlation coefficients (R² ≥ 0.9904) for the five mPAEs. Furthermore, the analytical method was also successfully applied to the highly sensitive detection of metabolite mPAEs in mouse plasma samples, indicating the promising application of the Fe₃O₄@TtDt@Cu²⁺ composites as a quick and efficient adsorbent in the sample pretreatment.

由于生物样品的复杂性，开发一种简单、高选择性和灵敏的邻苯二甲酸单酯 (mPAE) 分析方法仍然是一项挑战。为了解决这个问题，制备了具有核-壳结构的 Cu ²⁺固定磁性共价有机骨架（Fe ₃ O ₄ @TtDt@Cu ²⁺复合材料），通过一种简便的方法合成具有固有特性的 COFs 壳来提高 mPAEs 的富集效率Fe ₃ O ₄ NPs上的双官能团和进一步的 Cu ²⁺固定化。该复合材料具有高比表面积 (348.1 m ²  g ⁻¹ )、出色的饱和磁化强度 (34.94 emu g⁻¹ ), 有序介孔结构，Cu ²⁺固定化，热稳定性优异。据此，建立了基于Cu ²⁺固定化COF复合材料结合高效液相色谱-串联质谱（HPLC-MS/MS）的磁性固相萃取（MSPE）预处理技术，关键参数包括吸附剂用量、详细考察了吸附时间、洗脱溶剂等。开发的分析方法显示出宽线性范围 (10–8000 ng L ⁻¹ )、低检测限 (LOD, 2–10 ng L ⁻¹ ) 和良好的相关系数 (R ² ≥ 0.9904) 对于五个 mPAE。此外，该分析方法还成功应用于小鼠血浆样品中代谢物mPAEs的高灵敏度检测，表明Fe ₃ O ₄ @TtDt@Cu ²⁺复合材料作为快速高效的吸附剂在样品预处理中具有广阔的应用前景。