Fluorinated-Squaramide Covalent Organic Frameworks for High-Performance and Interference-Free Extraction of Synthetic...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Synthetic cannabinoids (SCs) are a growing global public health concern.
• Monitoring SCs in environmental water samples is crucial for consumption assessment.
• Effective enrichment of SCs from complex matrices remains a significant analytical challenge.

Purpose of the Study:

• To develop novel materials for selective and efficient enrichment of synthetic cannabinoids (SCs).
• To establish a sensitive analytical method for trace-level determination of SCs in water samples.

Main Methods:

• Synthesis of fluorinated-squaramide-based covalent organic frameworks (COFs), specifically FSQ-2, FSQ-3, and FSQ-4.
• Characterization of COF properties, including pore size and functional groups.
• Coupling the optimal COF (FSQ-4) with solid-phase microextraction (SPME) for SCs analysis.

Main Results:

• FSQ-4 demonstrated strong affinity and synergistic capture of various SCs due to its pore size (1.4 nm) and functional groups (H-bond donors/acceptors, fluorophilic segments).
• The FSQ-4/SPME system achieved trace-level (part per trillion) determination of 13 SCs.
• The method exhibited excellent extraction performance and stability under diverse interfering conditions.

Conclusions:

• Fluorinated-squaramide-based COFs, particularly FSQ-4, are highly effective for selective SCs enrichment.
• The FSQ-4/SPME method offers a sensitive and robust approach for monitoring SCs in environmental samples.
• This advancement significantly improves the analytical capabilities for NPS detection and public health surveillance.