Thiocarbamide conversion-based nitrogen-rich covalent organic framework coatings for electro-enhanced solid-phase...

Area of Science:

• Materials Science
• Analytical Chemistry
• Separation Science

Background:

• Efficient extraction of polar compounds is crucial for analytical chemistry.
• Fiber coatings with high polarity and electrochemical activity enhance solid-phase microextraction (SPME).
• Covalent organic frameworks (COFs) offer tunable properties for advanced materials.

Purpose of the Study:

• To design and prepare a novel COF fiber coating with enhanced polarity and electrochemical performance.
• To develop a sensitive method for determining trace bisphenols (BPs) using the new coating.
• To investigate the application of the developed method in real-world samples like tea beverages.

Main Methods:

• Fabrication of a nitrogen-rich thiocarbamide-linked COF coating via molecular design and post-synthetic modification.
• Utilizing the COF coating for electro-enhanced solid-phase microextraction (EE-SPME) of polar bisphenols.
• Coupling EE-SPME with gas chromatography-tandem mass spectrometry (GC-MS/MS) for sensitive determination.

Main Results:

• The COF coating exhibited high polarity and excellent electrochemical performance due to abundant O, N, and S functional groups.
• The EE-SPME method demonstrated high enrichment efficiency and durability for bisphenols.
• The GC-MS/MS method achieved wide linear ranges (2.0-800.0 ng L⁻¹), low detection limits (0.1-2.0 ng L⁻¹), and satisfactory recoveries (81.6 %–118.6 %) in tea beverages.

Conclusions:

• A feasible pathway for preparing high-polarity, electrochemically active COF coatings for EE-SPME was established.
• The developed method provides a sensitive and reliable approach for trace bisphenol determination in complex matrices.
• This research advances the application of COFs in analytical sample preparation.