Liquid-liquid-solid microextraction based on membrane-protected molecularly imprinted polymer fiber for trace...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Traditional sample preparation methods for trace analysis often face challenges with complex matrices and analyte recovery.
• Molecularly imprinted polymers (MIPs) offer high selectivity but can be affected by direct exposure to aqueous samples.
• Hollow fiber liquid-phase microextraction (HF-LPME) provides enrichment and sample cleanup but may lack specificity.

Purpose of the Study:

• To develop and validate a novel liquid-liquid-solid microextraction (LLSME) technique for enhanced sample preparation.
• To integrate the selectivity of MIPs with the enrichment and cleanup capabilities of HF-LPME.
• To overcome limitations of existing microextraction methods, particularly water interference in MIP-based techniques.

Main Methods:

• A porous membrane-protected molecularly imprinted polymer (MIP)-coated silica fiber was designed for LLSME.
• The technique involves a three-phase extraction process: aqueous sample, organic phase within a membrane, and MIP fiber.
• Extraction parameters (organic solvent, time) were optimized, and the method was coupled with High-Performance Liquid Chromatography (HPLC).

Main Results:

• The LLSME technique demonstrated high selectivity and efficiency for extracting terbutylazine.
• Optimized parameters led to low limits of detection (0.006-0.02 µg L⁻¹) and good recoveries in real samples.
• Repeatability was satisfactory, with relative standard deviations (RSD) ranging from 1.2% to 9.6% for real samples (n=5).

Conclusions:

• The developed LLSME method is a fast, selective, and sensitive pretreatment technique for trace analysis of triazines in complex aqueous samples.
• LLSME effectively combines the advantages of MIP-SPME and HF-LPME, offering a robust solution for challenging sample matrices.
• The method shows significant potential for real-world applications in environmental monitoring and food safety analysis.