Molecular complex-based dispersive liquid-liquid microextraction: analysis of polar compounds in aqueous solution

Area of Science:

• Analytical Chemistry
• Environmental Chemistry
• Separation Science

Background:

• Dispersive liquid-liquid microextraction (DLLME) traditionally uses water-immiscible organic solvents.
• Phenols are common environmental pollutants requiring sensitive detection methods.
• Efficient extraction of polar organic compounds from aqueous matrices remains a challenge.

Purpose of the Study:

• To develop a novel molecular complex-based DLLME method for phenol extraction.
• To utilize tri-n-butylphosphate (TBP) as a Lewis base extractant, avoiding traditional organic solvents.
• To establish a simplified and efficient method for analyzing phenols in environmental water samples.

Main Methods:

• A DLLME method employing hydrogen bond interaction between TBP and phenolic analytes.
• Optimization of extraction parameters including TBP volume, sample pH, and ionic strength.
• Phase separation and extractant collection using a disposable polyethylene pipet.

Main Results:

• Successful extraction of phenols (p-benzenediol, m-benzenediol, o-benzenediol, phenol) from environmental water.
• Achieved limits of detection (LOD) of 7-29 μg/L and limits of quantification (LOQ) of 25-98 μg/L.
• Demonstrated good linearity (r(2)≥0.9961), acceptable repeatability (RSDs < 13.9%), and recoveries (83.2%–117.8%).

Conclusions:

• The developed TBP-based DLLME method offers a novel, solvent-minimized approach for extracting polar organic compounds.
• The method provides a convenient and efficient alternative for phenol analysis in environmental monitoring.
• The use of a simple polyethylene pipet facilitates easy collection of the extractant layer.