The Solid-Phase Microextraction (SPME) technique has become one of the most widely used extraction techniques for environmental, food and clinical analyses. It is well suited for sample preparation resulting in reduced time per sample, less sample manipulation and solvent consumption.

Challenges of SPME Technique

However, the technique remained almost unchanged with some significant drawbacks, such as narrow range of commercial stationary phases available. Usually they are adsorbents, so the extraction mechanism is based on immobilization of analyte on the fiber surface. In case of samples characterized by complex matrix, lowered extraction efficiency can be observed. Another big challenge of SPME technique is limited possibility to extract polar organic analytes.

Application of Ionic Liquids as Extraction Media

The solution to this problem can be the application of ionic liquids as extraction media. Due to their unique physicochemical properties these compounds can be treated as green solvents and they can be successfully applied as SPME stationary phases. The key issue is obtaining stable film of ionic liquid on the fiber surface with simultaneous preservation of its liquid state.

Utilization of Sol-Gel Technique

The best solution for this, is utilization of sol-gel technique. Obtained hybrid structure - ionogel, possess uniform physical and chemical structure.

Aim of the Project

The aim of the project is to obtain the fibers covered with the ionogel and next implement them as SPME stationary phase for extraction of selected analytes from water samples.

First Step

1. A selection of ionic liquid that will comply with requirements such as: high thermal stability, availability in liquid state at room temperature, insolubility in water.
2. Preparation of hybrid silica-based material with immobilized ionic liquid by sol-gel technology. Obtain complete fibers covered with ionogel.
3. Characterization of coatings composition and morphology with scanning electron microscopy and energy dispersive X-ray spectrometry.

Next Step

The next step will include evaluation of extractability obtained ionogel SPME fibers with selected model volatile compounds from water samples.

Literature

1. Understanding Solid-Phase Microextraction: Key Factors Influencing the Extraction Process and Trends in Improving the Technique. Chem. Rev. 2013, 113, 1667¿1685.
2. Sol-gel technique-a versatile tool for adsorbent preparation. Crit. Rev. Anal. Chem. 2010, 40, 172-186.
3. Opportunities and shortcomings of ionic liquids in single-drop microextraction. Trac-Trends Anal. Chem. 2015, 72, 153¿168.
4. Silica-Based Ionogels: Nanoconfined Ionic Liquid-Rich Fibers for Headspace Solid-Phase Microextraction Coupled with Gas Chromatography¿Barrier Discharge Ionization Detection. Anal. Chem. 2014, 86, 11640¿11648.
5. Ionogel fibres of bis(trifluoromethanesulfonyl)imide anion-based ionic liquids for the headspace solid-phase microextraction of chlorinated organic pollutants. Analyst 2015, 140, 7417¿7422.