PFAS analysis
Researchers at the Korea Research Institute of Chemical Technology (KRICT), in collaboration with Chungnam National University, have developed a microfluidic chip capable of extracting and detecting trace pollutants directly from samples containing suspended solids.
The platform eliminates filtration and other conventional pre-treatment stages, enabling streamlined analysis of PFAS and pharmaceutical residues in challenging matrices.
Environmental and food safety analysis typically involves multiple preparatory stages before instrumental measurement. Water samples containing sand, soil, organic debris or food residues must usually be filtered to remove solids. This is followed by extraction and concentration steps to isolate target analytes.
These workflows increase processing time and solvent consumption. More importantly, filtration can reduce analytical accuracy by inadvertently removing hydrophobic or particle-associated contaminants alongside solids.
In trace analysis, particularly for PFAS or pharmaceutical residues, minor losses during preparation can significantly affect quantification.
Traditional liquid–liquid extraction (LLE) remains widely used but it requires relatively large solvent volumes and is difficult to automate.
Liquid–liquid microextraction (LLME) reduces solvent demand but still generally requires filtration when particulates are present. As a result, most current methods rely on a sequential chain of solid extraction and analysis.
The research team, led by Dr Ju Hyeon Kim at KRICT and Professor Jae Bem You at Chungnam National University, designed a trap-based microfluidic device that integrates extraction into a single continuous process.
A small extractant droplet is confined within a microchamber, while the sample solution flows through an adjacent microchannel.
As the sample passes, target analytes selectively transfer into the extractant phase through rapid mass transport at the microscale.
Suspended solids remain in the main flow path and exit the device without entering the extractant chamber.
This configuration allows extraction to occur without prior filtration. After the extraction step, the droplet containing concentrated analytes is retrieved and introduced into conventional analytical instrumentation.
The design reduces solvent use, shortens preparation time and improves compatibility with automation or field-deployable systems.
The team validated the device using two representative contaminants: perfluorooctanoic acid (PFOA), a regulated per- and polyfluoroalkyl substance (PFAS), and carbamazepine (CBZ), a widely detected anticonvulsant pharmaceutical.
PFOA was detected within five minutes, demonstrating rapid extraction kinetics. CBZ was successfully extracted directly from sand-containing slurry samples and subsequently identified using high-performance liquid chromatography (HPLC).
The results show that particulate-rich matrices do not compromise analyte recovery within the microfluidic system.
By integrating multiple pre-treatment steps into a single microfluidic process, the platform reduces the risk of analyte loss and lowers operational complexity. This has direct relevance for environmental monitoring, drinking water safety, food inspection and pharmaceutical residue analysis, where sample heterogeneity is common.
The approach also aligns with broader trends toward compact, automatable and potentially on-site analytical systems. Simplified preparation increases compatibility with unattended monitoring and high-throughput workflows.
The study was published in December 2025 in ACS Sensors. Dr Ju Hyeon Kim and Professor Jae Bem You served as corresponding authors, with Sung Wook Choi as first author.
IET 36.3 May
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