ZIF‐8 Selective Dispersive Solid‐Phase Extraction‐LC‐MS/MS Method for the Determination of Aconitine alkaloids in Rat Plasma: Application in Pharmacokinetic Studies

Objective: Aconitine alkaloids, as the principal bioactive constituents of Fuzi, pose a significant challenge to its clinical application due to their toxicity. This study aimed to establish a rapid, efficient, and stable method for quantifying monoester-type and diester-type alkaloids in raw Fuzi using zeolitic imidazolate framework-8 (ZIF-8). The method was subsequently applied to pharmacokinetic studies in rats, offering valuable insights into the safe clinical use of Fuzi. Methods: Synthetic ZIF-8 was employed as the microextraction adsorbent, with optimization of extraction parameters such as ZIF-8 content, shaker speed, extraction time, and sodium ion concentration to maximize enrichment efficiency. A dispersive solid-phase extraction-liquid chromatography-tandem mass spectrometry (d-SPE-LC-MS/MS) method, based on ZIF-8, was developed and validated for method performance. The pharmacokinetics of five aconitine alkaloids in Fuzi were investigated, ensuring efficient extraction and analysis. Results: Under the optimized conditions, the d-SPE method demonstrated robust enrichment of aconitine alkaloids. A strong linear relationship was established for aconitine, hypaconitine, mesaconitine, lappaconitine, and benzoylaconitine within the concentration range of 0.3125-1000 ng/mL, with correlation coefficients exceeding 0.99. The LC-MS/MS assay achieved a detection limit as low as 0.104 ng/mL. Additionally, the pharmacokinetic analysis revealed rapid absorption of the five alkaloids, with benzoylaconitine exhibiting a Tmax of 0.25 h. Conclusion: This study introduces a novel d-SPE-LC-MS/MS method based on ZIF-8 for the analysis of aconitine alkaloids in plasma, facilitating pharmacokinetic studies of Fuzi. These findings substantially contribute to a deeper understanding of the in vivo pharmacokinetics of aconitine alkaloids.