A modulation approach for covalent organic frameworks: Application to solid phase microextraction of phthalate esters

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Phthalate esters (PAEs) are common environmental pollutants with potential health risks.
• Developing efficient extraction methods for PAEs is crucial for environmental monitoring.
• Covalent organic frameworks (COFs) offer promising properties for advanced analytical applications.

Purpose of the Study:

• To design and synthesize novel 2,4,6-triphenoxy-1,3,5-benzene-based COFs using a modulation approach.
• To utilize these COFs as solid phase microextraction (SPME) coatings for the efficient extraction of PAEs.
• To optimize the extraction process and evaluate the performance of the developed SPME method.

Main Methods:

• Synthesis of COFs using 4-hydroxybenzhydrazide as a modulating agent.
• Fabrication of SPME fibers coated with the synthesized COFs.
• Optimization of extraction parameters: temperature, time, salt concentration, and desorption time.
• Analysis of PAEs using optimized SPME conditions and evaluation of linearity, detection limits, and precision.

Main Results:

• The modulation approach significantly enhanced the extraction efficiency of PAEs.
• Optimized SPME method achieved a linear range of 1-100 μg/L with good linearity (0.9904-0.9970).
• Low detection limits (0.032-0.451 μg/L) and good reproducibility (RSDs < 9.73%) were obtained.
• Satisfactory recoveries were achieved for PAEs in real water samples.

Conclusions:

• The developed COF-based SPME coating offers a highly efficient and sensitive method for PAE extraction.
• The modulation strategy is effective in improving the performance of COF materials for analytical applications.
• This approach provides a valuable tool for the environmental monitoring of PAEs.