Reduction of extraction times in liquid-phase microextraction

Area of Science:

• Analytical Chemistry
• Forensic Toxicology

Background:

• Liquid-phase microextraction (LPME) using porous hollow fibers offers a simple and cost-effective method for sample preparation.
• Previous methods required longer extraction times, limiting throughput.

Purpose of the Study:

• To significantly reduce extraction times for LPME by increasing the surface area of porous polypropylene hollow fibers.
• To evaluate the efficiency of LPME for extracting model drugs from various biological matrices, including whole blood.

Main Methods:

• Comparison of two commercially available porous polypropylene hollow fibers with different surface areas.
• Optimization of extraction parameters including sample matrix (urine, plasma, whole blood), dilution, alkalization, and acceptor phase.
• Analysis of model compounds (methamphetamine and citalopram) using the optimized LPME technique.

Main Results:

• Increasing the hollow fiber surface area by approximately two-fold reduced equilibrium extraction times by a similar factor.
• Equilibrium was achieved within 15 minutes for urine and plasma, and 30 minutes for whole blood.
• Extraction recoveries ranged from 60% to 100% for methamphetamine and citalopram across different matrices and fiber types.

Conclusions:

• Optimized porous hollow fiber LPME allows for rapid and efficient extraction of drugs from urine, plasma, and for the first time, whole blood.
• The method provides comparable sample clean-up and extraction recoveries to plasma, demonstrating its versatility.
• This technique offers a faster and effective approach for drug analysis in forensic and clinical toxicology.