Polydopamine-based immobilization of zeolitic imidazolate framework-8 for in-tube solid-phase microextraction

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Zeolitic imidazolate frameworks (ZIFs), a type of metal-organic framework (MOF), are promising porous materials for sample preparation.
• Immobilizing ZIFs within robust materials like poly(ether ether ketone) (PEEK) is crucial for developing stable analytical devices.
• Poly(dopamine) (PDA) offers versatile surface modification capabilities due to its adhesive and reactive properties.

Purpose of the Study:

• To develop a novel bio-inspired polydopamine (PDA) method for immobilizing ZIF-8 within a PEEK tube.
• To create an online solid-phase microextraction (SPME) system using the ZIF-8-PDA-PEEK material.
• To evaluate the extraction efficiency and analytical performance for polycyclic aromatic hydrocarbons (PAHs).

Main Methods:

• Assembly of a PDA layer inside a PEEK tube.
• Immobilization of ZIF-8 onto the PDA-coated PEEK tube via noncovalent and covalent interactions.
• Characterization of the ZIF-8-PDA-PEEK material using SEM and EDX.
• Development of an online SPME-HPLC method for PAH analysis.

Main Results:

• The ZIF-8-PDA-PEEK material was successfully synthesized and characterized.
• The developed online SPME system demonstrated high extraction efficiency for six PAHs, with enrichment factors ranging from 550 to 734.
• The SPME-HPLC method exhibited good linearity (10-5000 pg/mL) and low detection limits (0.5-5 pg/mL) for the target PAHs.
• Successful determination of PAHs in environmental samples with high recoveries (82.5-98.6%).

Conclusions:

• The bio-inspired PDA method provides an effective strategy for immobilizing ZIF-8 within PEEK tubes for online SPME applications.
• The ZIF-8-PDA-PEEK material shows excellent potential for the sensitive and efficient extraction of PAHs.
• The developed online SPME-HPLC method is a viable tool for monitoring PAHs in environmental matrices.