Electrospun ZIF-8-enhanced fibers for fabric phase extraction of phenytoin from plasma samples followed by high performance liquid chromatography-tandem mass spectrometry analysis.

A fabric phase extraction method using a zeolitic imidazolate framework-8 (ZIF-8) enhanced fiber as an effective sorbent was developed for the extraction of phenytoin from plasma samples prior to its measurement by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). ZIF-8 metal organic framework (MOF) was analyzed by Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The coordination between 2-methylimidazole and zinc centers, with a distinct ZnN stretching vibration observed at 422 cm-1, alongside characteristic aromatic and aliphatic CH stretching bands at 3134 and 2927 cm-1, respectively. The XRD pattern exhibited sharp, intense peaks at 2θ = 10.60, 12.80, 14.80, 17.70, and 26.40, relating to the crystal planes of 002, 112, 022, 222, and 013, respectively, confirming the formation of highly crystalline ZIF-8. SEM micrographs further revealed a homogeneous morphology consisting of well-defined polyhedral nanocrystals with sharp edges and flat, distinct surfaces. By executing the provided procedure under optimal conditions, satisfactory extraction recovery (ER) (64%), good precision (relative standard deviations (RSDs) of ≤3.9% for intra-day and ≤ 4.6% for inter-day precisions, and low limits of detection (LOD) (0.89 ng mL-1) and quantification (LOQ) (2.9 ng mL-1) were achieved. The applicability of the proposed method was evaluated using spiked plasma samples.