Development and evaluation of plunger-in-needle liquid-phase microextraction

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Liquid-phase microextraction (LPME) is a sample preparation technique used to isolate and concentrate analytes from complex matrices.
• Traditional LPME methods often involve multiple steps and require specialized equipment, limiting their speed and simplicity.
• There is a need for faster, simpler, and more environmentally friendly extraction techniques for analyzing environmental pollutants.

Purpose of the Study:

• To develop a novel, simple, and fast one-step liquid-phase microextraction (LPME) approach.
• To utilize a modified plunger wire as an integrated extractant solvent holder and sample introduction device.
• To evaluate the efficiency of the developed method for the extraction of polycyclic aromatic hydrocarbons (PAHs).

Main Methods:

• A plunger-in-needle LPME technique was developed using a stainless steel plunger wire etched with hydrofluoric acid to create a microporous structure.
• The etched plunger wire was used to hold the extractant solvent, and analytes diffused from the sample solution into the solvent.
• Extracted analytes were analyzed using gas chromatography-mass spectrometry (GC-MS) after thermal desorption directly from the plunger wire.

Main Results:

• The method achieved low method detection limits for 10 PAHs, ranging from 0.003 to 0.136 μg/L.
• Relative standard deviations were between 2.9% and 9.6%, indicating good reproducibility.
• Linearity was observed in the range of 0.05–50 μg/L or 1–50 μg/L, and relative recoveries for spiked river water samples ranged from 70.1% to 106.4%.

Conclusions:

• The plunger-in-needle LPME is a fast, simple, and efficient method for extracting PAHs.
• The integrated extraction and analysis device eliminates the need for extraneous sorbents, reducing solvent consumption and waste.
• This environmentally friendly approach demonstrates excellent performance for the analysis of PAHs in environmental samples.