Research News from SamplePrep@UiO - Department of Pharmacy

Frederik André Hansen is Top 40 under 40 with analytical chemistry

Published Sep. 28, 2026 1:58 PM

Postdoc Frederik André Hansen has been included in Top 40 under 40 Power list of The Analytical Scientist. Click here to see who else is on the list.

Hydrophilic peptides in urine

Published Aug. 7, 2026 9:22 AM

In collaboration with scientists from Sichuan University and Sichuan Cancer Hospital, we have developed a high-throughput electromembrane extraction (EME) platform for the analysis of endogenous peptides in urine, one of the most challenging classes of compounds in sample preparation. By comparing conventional liquid membranes with deep eutectic solvent-based membranes, we reveal fundamentally different extraction mechanisms and demonstrate rapid, green, and efficient peptide enrichment in a 96-well format. Importantly, we introduce a log P-charge dual-factor model that predicts peptide extraction behavior from molecular properties, providing a new framework for the rational design of EME systems and expanding the potential of EME in biomarker discovery and clinical diagnostics.

Reviewing enantioselective LLE

Published Aug. 7, 2026 9:19 AM

In collaboration with scientists from Jiangxi University of Chinese Medicine and Hangzhou Normal University, we have reviewed the state of the art in enantioselective liquid-liquid extraction (ELLE), an emerging separation technology with the potential to deliver enantiopure compounds at industrial scale. The review guides readers through the fundamental principles of chiral recognition, solvent-system design, chiral additives, and extraction equipment, while highlighting recent advances in ionic liquids, deep eutectic solvents, and biphasic extraction systems. By connecting molecular-level mechanisms with process-scale implementation, we show how ELLE can evolve into a sustainable and cost-effective alternative to conventional chiral separation technologies.

Plastic use in clinical LC-MS analysis

Published Aug. 7, 2026 9:17 AM

In collaboration with scientists from the University of Oslo and Oslo University Hospital, we have investigated an often-overlooked aspect of analytical chemistry: the environmental cost of sample preparation. Using ketamine analogues in whole blood as a case study, we compared protein precipitation, liquid-liquid extraction, and electromembrane extraction (EME) in terms of analytical performance, plastic consumption, solvent use, and overall sustainability. While all methods performed similarly analytically, EME reduced plastic consumption by 40%, used far less organic solvent, and achieved the highest greenness score. The study proposes a practical benchmark for plastic use in clinical and forensic laboratories and highlights the potential of EME as a more sustainable sample preparation platform for future bioanalytical workflows.

Published Aug. 7, 2026 9:14 AM

In collaboration with scientists from Sichuan University and the University of Oslo, we have developed a high-throughput 96-well electromembrane extraction (EME) method for the simultaneous determination of 22 veterinary drug residues in honey, milk, and eggs. Central to the work is a specially designed deep eutectic solvent (DES) liquid membrane, which combines strong hydrogen-bonding and aromatic interactions to enable efficient extraction of diverse drug classes. The method offers excellent analytical performance, low solvent consumption, and high sample throughput, while achieving a strong greenness score. This study highlights the growing potential of DES-based EME as a sustainable and highly versatile platform for food safety monitoring and multiresidue analysis.

EME of tetracyclines from food samples

Published Aug. 7, 2026 9:12 AM

We have demonstrated the first successful application of electromembrane extraction (EME) for tetracycline antibiotics in complex food and biological samples, including milk, egg white, honey, and human plasma. By developing a new liquid membrane tailored for these highly polar and zwitterionic compounds, we achieved efficient extraction, excellent analytical performance, and minimal matrix effects. The study also reveals how different sample matrices influence EME behavior, showing that matrix-specific optimization is often required. Beyond residue analysis, the work provides important new insights into the extraction mechanisms of challenging polar compounds and further expands the scope of EME for green and sustainable sample preparation...

EME methods guided by machine learning!

Published Aug. 7, 2026 9:10 AM

In collaboration with scientists from the University of the Balearic Islands, we have developed the first machine learning framework for quantitative prediction and in silico optimization of electromembrane extraction (EME). Using data from 182 chemically diverse compounds and five generic liquid membranes, we trained neural network models capable of predicting extraction recoveries directly from molecular properties and experimental conditions. To make the technology accessible, we also developed EME Predictor, a free desktop application that recommends optimal extraction conditions for new analytes. This work demonstrates how EME method development can move beyond trial-and-error toward data-driven, predictive, and more sustainable analytical workflows...

On-chip EME with micropillars

Published Aug. 7, 2026 9:06 AM

In collaboration with scientists from the University of Copenhagen, we have developed a new microfluidic platform for electromembrane extraction (EME) based on a free liquid membrane stabilized by arrays of microscopic pillars. Unlike conventional systems, the liquid membrane can be rapidly replenished without disassembling the device, enabling extended reuse and greater experimental flexibility. The microchip operated at remarkably low voltages while providing efficient extraction and minimal carryover. As a first proof-of-concept, the study demonstrates how microfluidics and EME can be combined into a highly sustainable, reusable, and potentially field-deployable sample preparation platform, while also identifying current limitations in extraction efficiency that will guide future device development...

Published Aug. 7, 2026 9:02 AM

In collaboration with scientists from the IUPAC project “Greenness of Official Standard Sample Preparation Methods”, we have evaluated the environmental footprint of 174 official analytical methods and 332 method variants from ISO, CEN, and major pharmacopoeias using the AGREEprep assessment tool. The results reveal that most standard methods still rely on solvent-intensive, energy-demanding, and waste-generating sample preparation procedures, with 67% scoring below 0.2 on a greenness scale from 0 to 1. By identifying the key weaknesses of current workflows, this study highlights the urgent need to modernize official methods and accelerate the adoption of greener, more sustainable sample preparation technologies already available to the analytical community…

Published Aug. 6, 2026 11:39 AM

In collaboration with scientists from Chulalongkorn University, the University of Oslo, and the Czech Academy of Sciences, we have developed the first 96-well gel-based electromembrane extraction (EME) system. By replacing conventional oil membranes with agarose gels, we demonstrate a fundamentally different extraction mechanism, where selectivity is governed by transport through an aqueous gel network rather than partitioning into an organic solvent. The study highlights the potential of gel-EME as a high-throughput, greener, and highly tunable platform for the extraction of polar analytes while providing efficient cleanup of proteins and phospholipids from plasma. At the same time, we identify important limitations, including electroendosmosis, high extraction currents, and reduced capacity for complex biological samples, providing a roadmap for the future development of gel-based extraction technologies...

Published Aug. 6, 2026 11:31 AM

In collaboration with scientists from the University of Valencia, we have challenged a fundamental assumption in three-phase liquid membrane extraction (LME): that extraction across the membrane must be driven by ionization. We demonstrate that weakly acidic compounds can instead be extracted as neutral species using a solvent gradient created by a DMSO-water acceptor phase, eliminating the need for highly alkaline conditions. The study provides new insight into mass-transfer mechanisms in LME, broadens the range of compounds amenable to extraction, and opens new opportunities for mild, efficient sample preparation of complex biological samples...

Published Aug. 6, 2026 11:17 AM

In collaboration with scientists from Sichuan University, we have explored how the composition of the liquid membrane governs electromembrane extraction (EME) of veterinary drug residues in food. Using 80 prohibited or restricted veterinary compounds as model analytes, we developed three complementary liquid membranes that enabled selective extraction of multiple drug classes in a high-throughput 96-well format. The study provides new insights into the molecular interactions behind EME selectivity and establishes a practical framework for applying EME to food safety analysis, including the detection of drug residues in honey samples...

Published Aug. 6, 2026 11:16 AM

In this tutorial, we show how response surface methodology (RSM) can transform the optimization of electromembrane extraction (EME) from a trial-and-error exercise into a systematic and highly efficient process. We guide readers through every step of the workflow, from selecting the most relevant EME parameters and designing experiments, to building, evaluating, and interpreting statistical models. Supported by practical case studies, the tutorial highlights how RSM can reveal parameter interactions, identify optimal extraction conditions, and accelerate the development of robust, efficient, and greener EME methods…

Published Aug. 6, 2026 11:10 AM

In collaboration with scientists from Hangzhou Normal University, Central South University, and other international partners, we have reviewed the rapidly evolving landscape of sample preparation for polar metabolites in biological samples. From amino acids and nucleotides to sugar phosphates and CoA derivatives, we examine the strengths, limitations, and emerging trends of modern extraction technologies, including SPE, SPME, LPME, and electromembrane extraction (EME). The review provides practical guidance for selecting appropriate methodologies while highlighting opportunities for greener, more automated, and higher-performance workflows in metabolomics and bioanalysis...

Published Feb. 26, 2025 7:55 AM

In collaboration with scientists from the Department of Chemistry, UiO, we have demonstrated that EME provides exhaustive removal of proteins and cell medium components, while providing high extraction efficiency of pharmaceutical drugs and their metabolites after incubation of human stem-cell-derived liver organoids. This highlights the potential for EME to be implemented in organ-on-a-chip systems that may replace human and animal models during drug development…

Published Jan. 22, 2025 7:42 AM

Drugs of abuse can be detected in hair long time after exposure, and therefore hair samples are important in forensic toxicology. Now we have tested EME for hair samples for the first time, and developed the extraction chemistry and documented performance for 18 common drugs of abuse. The experiments were conducted with the commercial EME device, in collaboration with Oslo University Hospital. The idea behind this research is to illustrate the potential of EME, and how new EME methods are developed based on our current understanding of the concept.

Published Jan. 22, 2025 7:39 AM

For long time, we have been working with EME of peptides. In a recent project, we tested for the first time EME of a protein. We selected hCG as model protein, and used extraction conditions previously optimized for peptides. We were unable to extract the intact protein, but extraction of signature peptide after tryptic digestion of the protein was feasible. We will definitely do more experiments with proteins, based on what we have learned from the current project…

Published Jan. 21, 2025 10:50 AM

Peptides are small pieces of protein, and they play a vital role in biology. For this reason, we have been studying EME of peptides for a while. This work has been done with a small selection of model peptides. To give this research a more general anchor, we recently studied EME of 6,000 peptides in collaboration with scientists from Technical University of Munich. From this very fundamental and complex study, we learned that extraction efficiency is related to peptide polarity and charge, and that a surprisingly high number of peptides can be extracted by EME.

Published Mar. 5, 2024 12:30 PM

Looking back into research papers on electromembrane extraction (EME), a jungle of different liquid membranes has been used, and they have been developed more or less by trial-and-error type of experiments. The last year, we have put a lot of efforts into standardizing stable and efficient liquid membranes, to propose generic extraction conditions to bases and acids of different polarity. A recent paper is one contribution in a series of papers, where we have optimized generic conditions for basic substances with low and moderate polarity