A5028953299- Analytical Chemistry and Chromatography
- Mass Spectrometry Techniques and Applications
- Metabolomics and Mass Spectrometry Studies
- Pesticide Residue Analysis and Safety
- Analytical chemistry methods development
- Advanced Chemical Sensor Technologies
- Microfluidic and Capillary Electrophoresis Applications
- Toxic Organic Pollutants Impact
- Pharmaceutical and Antibiotic Environmental Impacts
- Coffee research and impacts
- Electrohydrodynamics and Fluid Dynamics
- Pharmacological Effects and Assays
- Insect and Pesticide Research
- Water Quality Monitoring and Analysis
- Computational Drug Discovery Methods
- Supramolecular Chemistry and Complexes
- Spectroscopy and Chemometric Analyses
- Chemical Safety and Risk Management
- Per- and polyfluoroalkyl substances research
- Plant and animal studies
- Innovative Microfluidic and Catalytic Techniques Innovation
- Pesticide and Herbicide Environmental Studies
- Environmental Toxicology and Ecotoxicology
- Molecular Sensors and Ion Detection
- Pesticide Exposure and Toxicity
Stockholm University
2020-2025
University of Tartu
2012-2021
Freie Universität Berlin
2017-2019
Technion – Israel Institute of Technology
2017-2018
University of Helsinki
2011
Ionization efficiency (IE) of different compounds in electrospray ionization (ESI) source differs widely, leading to widely differing sensitivities ESI-MS analytes. An approach for quantifying ESI efficiencies (as logIE values) and setting up a self-consistent quantitative experimental scale organic under predefined conditions (ionization by monoprotonation) has been developed recently. Using this containing 62 chemical nature ranging 6 orders magnitude established. The is based on over 400...
Abstract Increasing production and use of chemicals awareness their impact on ecosystems humans has led to large interest for broadening the knowledge chemical status environment human health by suspect non-target screening (NTS). To facilitate effective implementation NTS in scientific, commercial governmental laboratories, as well acceptance managers, regulators risk assessors, more harmonisation is required. address this, NORMAN Association members involved activities have prepared this...
Electrospray ionization (ESI) in the negative ion mode has received less attention fundamental studies than positive electrospray ionization. In this paper, we study efficiency of formation ESI source via deprotonation substituted phenols and benzoic acids explore correlations obtained values (logIE) with different molecular properties. It is observed that stronger (i.e., fully deprotonated droplets) yielding anions highly delocalized charge [quantified by weighted average sigma (WAPS)...
Non-targeted and suspect analyses with liquid chromatography/electrospray/high-resolution mass spectrometry (LC/ESI/HRMS) are gaining importance as they enable identification of hundreds or even thousands compounds in a single sample. Here, we present an approach to address the challenge quantify identified from LC/HRMS data without authentic standards. The uses random forest regression predict response ESI/HRMS mean error 2.2 2.0 times for ESI positive negative mode, respectively. We...
Formation of sodium adducts in electrospray (ESI) has been known for long time, but not used extensively practice, and several important aspects Na + adduct formation ESI source have almost unexplored: the ionization efficiency different molecules via formation, its dependence on molecular structure ion concentration solution, fragmentation behaviour as well ruggedness (a prerequisite wider practical use) formation. In this work, we developed a parameter describing (SAFE) neutral built SAFE...
For the first time, electrospray ionization efficiency (IE) scales in positive and negative mode are united into a single system enabling direct comparison of IE values across modes. This is made possible by use reference compound that ionizes to similar extent both Thus, choosing optimal (i.e., most sensitive) conditions for given set analytes enabled. Ionization efficiencies 33 compounds ionizing modes demonstrate that, contrary general practice, allows better sensitivity 46% such whereas...
Adduct formation is a common ionization method in electrospray mass spectrometry (ESI/MS). However, this process poorly understood and complicated to control. We demonstrate possibilities control adduct via mobile phase additives ESI positive mode for 17 oxygen nitrogen bases. Mobile were found be very effective measure manipulating the efficiencies of adducts. An appropriate choice additive may increase sensitivity by up three orders magnitude. In general, sodium [M + Na]+ protonated...
This Feature aims at giving an overview of different possibilities for quantitatively comparing the results obtained from LC−HRMS-based nontargeted analysis. More specifically, quantification via structurally similar internal standards, isotope labeling strategies, radiolabeling, and predicted ionization efficiencies are reviewed.
Abstract The Partnership for Chemicals Risk Assessment (PARC) is currently under development as a joint research and innovation programme to strengthen the scientific basis chemical risk assessment in EU. plan bring assessors managers together with scientists accelerate method production of necessary data knowledge, facilitate transition next-generation evidence-based assessment, non-toxic environment European Green Deal. NORMAN Network an independent, well-established competent network more...
To achieve water quality objectives of the zero pollution action plan in Europe, rapid methods are needed to identify presence toxic substances complex samples. However, only a small fraction chemicals detected with nontarget high-resolution mass spectrometry can be identified, and fewer have ecotoxicological data available. We hypothesized that could predicted for unknown molecular features data-rich (HRMS) spectra, thereby circumventing time-consuming steps identification rapidly flagging...
Nontarget analysis by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) is now widely used to detect pollutants in the environment. Shifting away from targeted methods has led detection of previously unseen chemicals, and assessing risk posed these newly detected chemicals an important challenge. Assessing exposure toxicity with nontarget HRMS highly dependent on knowledge structure chemical. However, majority features screening remain unidentified therefore assessment...
High-resolution mass spectrometry (HRMS)-based suspect and nontarget screening has identified a growing number of novel per- polyfluoroalkyl substances (PFASs) in the environment. However, without analytical standards, fraction overall PFAS exposure accounted for by these suspects remains ambiguous. Fortunately, recent developments ionization efficiency (IE) prediction using machine learning offer possibility to quantify lacking standards. In present work, gradient boosted tree-based model...
Electrospray (ESI) ionization efficiencies (IE) of a set 10 compounds differing by chemical nature, extent in solution (basicity), and hydrophobicity (tetrapropylammonium tetraethylammonium ion, triethylamine, 1-naphthylamine, N,N-dimethylaniline, diphenylphthalate, dimethylphtahalate, piperidine, pyrrolidine, pyridine) have been measured seven mobile phases (three acetonitrile percentages 20%, 50%, 80%, three different pH-adjusting additives, 0.1% formic acid, 1 mM ammonia, pH 5.0 buffer...
Electrospray ionization efficiency is known to be affected by mobile phase composition. In this paper, a detailed study of analyte dependence on pH presented. The effect was studied 28 compounds with different chemical properties. Neither pK nor solution degree itself observed sufficient at describing how aqueous affects the analyte. Therefore, behavior related various physicochemical properties via linear discriminant analyses. Distinction between pH-dependent and pH-independent achieved...
Abstract A wide range of micropollutants can be monitored with non-targeted screening; however, the quantification newly discovered compounds is challenging. Transformation products (TPs) are especially problematic because analytical standards rarely available. Here, we compared three approaches for non-target that do not require availability standards. The comparison based on a unique set concentration data 341 compounds, mainly pesticides, pharmaceuticals, and their TPs in 31 groundwater...
Nontargeted screening (NTS) utilizing liquid chromatography electrospray ionization high-resolution mass spectrometry (LC/ESI/HRMS) is increasingly used to identify environmental contaminants. Major differences in the efficiency of compounds ESI/HRMS result widely varying responses and complicate quantitative analysis. Despite an increasing number methods for quantification without authentic standards NTS, approaches are evaluated on limited diverse data sets with chemical coverage collected...