Current Research

Extraction and Measurement of Environmental Pollutants

For the past several summers, my students and I have been examining new methods of extracting and measuring pollutants in the environment. These extraction methods include solid-phase extraction (SPE), solid-phase microextraction (SPME), and paper-based extraction, followed by measurement with gas chromatography mass spectrometry (GC-MS) or high-performance liquid chromatography (HPLC). 

One recent project has involved a collaboration with Prof. Jared Anderson at Iowa State University. Dr. Anderson’s research group synthesizes new types of polymerized ionic liquids (PILs) and uses them to extract target molecules for measurement through a process called solid-phase microextraction (SPME). The figure below shows a typical SPME experiment. A fiber coated with the PIL (A) is either immersed in a liquid solution, or placed in the headspace above a solution, where target analyte molecules stick to the coating (B). The coated fiber is then removed (C) and placed in a heated oven where the analytes desorb (C) and are carried by helium gas to a gas chromatograph where they are detected and measured.

Different PILs coatings can be created to specifically adsorb certain classes of analyte molecules. In the past we have worked with PILs coatings designed to measure sunscreen agents in water, short chain fatty acids in wine, and phthalate esters in water, and then compared these coatings to ones that are commercially available.

Research posters from recent summer work:

• 2023 - Green analytical chemistry principles applied to the extraction of endocrine disruptors from water 

• 2022 - Extraction of bisphenol-A in water samples using solid phase extraction (SPE) followed by GC-MS and HPLC analysis

• 2021 - Comparison of commercial and polymerized ionic liquid coatings in determining phthalate esters using solid-phase microextraction

• 2020 - Determination of phthalate esters in Minnesota water bodies using head space solid-phase microextraction

• 2018 - Polymerized ionic liquid coatings for solid-phase microextraction of short-chain fatty acids from aqueous solution

• 2017 - An investigation of polymerized ionic liquids for solid-phase microextraction of sunscreen agents from aqueous solution