Restricted access magnetic core-mesoporous shell microspheres with C8-modified interior pore-walls for the...

Area of Science:

• Analytical Chemistry
• Materials Science
• Pharmacokinetics

Background:

• Accurate determination of diazepam in biological samples is crucial for pharmacokinetic studies.
• Existing methods for diazepam analysis in plasma often require extensive sample pretreatment.
• Novel enrichment techniques are needed to improve efficiency and accuracy.

Purpose of the Study:

• To develop and validate a novel enrichment technique for diazepam determination in rat plasma.
• To utilize C8-modified magnetic mesoporous microspheres (C8-Fe₃O₄@mSiO₂) for efficient diazepam extraction.
• To enable direct analysis of diazepam in plasma using Liquid Chromatography-Mass Spectrometry (LC-MS).

Main Methods:

• Synthesis of C8-Fe₃O₄@mSiO₂ microspheres with C8-modified interior pore-walls.
• Application of the microspheres for magnetic solid-phase extraction of diazepam from rat plasma.
• Optimization of extraction conditions, including microsphere amount, adsorption time, and elution parameters.
• Method validation including linearity, limit of detection, precision, and recovery.

Main Results:

• The C8-Fe₃O₄@mSiO₂ microspheres demonstrated efficient adsorption of diazepam via hydrophobic interaction.
• Protein molecules were excluded from the mesoporous channels, allowing direct extraction without pretreatment.
• Simple and rapid magnetic separation of the microspheres facilitated easy elution of diazepam.
• The developed method showed good linearity, low detection limits, high precision, and recovery.

Conclusions:

• The proposed method using C8-Fe₃O₄@mSiO₂ microspheres is a simple, accurate, and efficient approach for diazepam analysis in rat plasma.
• This technique offers a promising alternative for analyzing plasma concentrations and pharmacokinetics of similar drugs.
• The magnetic mesoporous microspheres provide a versatile platform for bioanalytical sample preparation.