A5070086178- Analytical Chemistry and Chromatography
- Mass Spectrometry Techniques and Applications
- Molecular spectroscopy and chirality
- Microfluidic and Capillary Electrophoresis Applications
- Chemical Synthesis and Analysis
- Axial and Atropisomeric Chirality Synthesis
- Atmospheric chemistry and aerosols
- Crystallization and Solubility Studies
- Chromatography in Natural Products
- Supramolecular Chemistry and Complexes
- Atmospheric Ozone and Climate
- Asymmetric Synthesis and Catalysis
- Molecular Sensors and Ion Detection
- Spectroscopy and Laser Applications
- Atmospheric and Environmental Gas Dynamics
- Chemical Reactions and Isotopes
- Analytical chemistry methods development
- Supramolecular Self-Assembly in Materials
- Water Quality Monitoring and Analysis
- Advanced Biosensing Techniques and Applications
- Analytical Methods in Pharmaceuticals
- Metabolomics and Mass Spectrometry Studies
- Advanced Proteomics Techniques and Applications
- Glycosylation and Glycoproteins Research
- Carbohydrate Chemistry and Synthesis
University of Helsinki
2016-2023
University of Vienna
2004-2016
Centre National de la Recherche Scientifique
2005
Universitat de Barcelona
2002-2004
University of Tübingen
2004
Christian Doppler Laboratory for Thermoelectricity
2004
North Dakota State University
2003
University of Jyväskylä
2002
Indiana University – Purdue University Indianapolis
2002
University of Ljubljana
2001
Significance Recycling of reactive iodine from heterogeneous processes on sea-salt aerosol was hypothesized over two decades ago to play an important role in the atmospheric cleansing capacity. However, understanding this mechanism has been limited laboratory studies and not confirmed atmosphere until now. We present measurement gas-phase interhalogen species show that their production via processing marine aerosols is remarkably fast. These observations reveal recycling atomic through...
Four diastereomeric chiral stationary phases (CSPs) based on quinine, quinidine, epiquinine, and epiquinidine tert-butyl carbamate selectors were synthesized evaluated under ion exchange HPLC conditions with a set of racemic N-acylated N-oxycarbonylated α-amino acids as selectands. The enantioseparation potential quinine- quinidine-derived CSPs proved to be far superior that their C9-epimeric congeners. absolute configuration C9 stereogenic center the cinchonan backbone these was identified...
A cinchona alkaloid having extraordinary chiral discriminatory powers (α = 32.6 for dinitrobenzoyl leucine) is developed as a stationary phase (CSP) chromatography. An explanation of how discrimination takes place presented. Using soluble analogue the CSP, we found that NMR spectrometry indicates 1:1 complexes exist both optical isomers interacting with free base form CSP exists in an open/closed ratio 35/65 but protonated, bound-state exclusively anti-open conformation, and significant...
Abstract. The multi-scheme chemical ionisation inlet 1 (MION1) enables rapid switching between the measurement of atmospheric ions without and neutral molecules using various pressure methods. In this study, we introduce upgraded version, 2 (MION2). new design incorporates enhanced ion optics, resulting in increased reagent concentration, ensuring a robust operation, enabling use multiple methods with same time. order to simplify regular calibration MION2, developed an open-source flow...
A countercurrent chromatography protocol for support-free preparative enantiomer separation of the herbicidal agent 2-(2,4-dichlorphenoxy)propionic acid (dichlorprop) was developed utilizing a purposefully designed, highly enantioselective chiral stationary-phase additive (CSPA) derived from bis-1,4-(dihydroquinidinyl)phthalazine. Guided by liquid−liquid extraction experiments, solvent system consisting 10 mM CSPA in methyl tert-butyl ether and 100 sodium phosphate buffer (pH 8.0) identified...
A preferred choice: Prochiral 3,3′,5,5′-tetramethyl-4,4′-bipyridine can be converted into two types of axially chiral 4,4′-bipyridine compounds, separable enantiomers by HPLC. The obtained enantiopure bipyridines were sufficiently stable in solution to used the self-assembly metallo-supramolecular squares, which reveal a remarkable preference for one ten possible structures (shown here). Supporting information this article is available on WWW under...
All-R/all-S enantiomers of oligoalanines (Alan, n = 1−10) with N-terminal protection group have been separated by HPLC on chiral stationary phases based various cinchona alkaloid selectors. Structure−enantioselectivity relationships derived extensive selector structure optimization provided insights into binding mechanisms and recognition. Their interpretation was supported X-ray crystal structures amino acid dipeptide, respectively, in complex selector. Optimized selectors bulky elements...
The surface chemistry of a chiral stationary phase (CSP) with (tert-butyl carbamoyl) quinine selector immobilized on thiol-modified silica has been characterized by (1)H HR/MAS NMR and (29)Si CP/MAS spectroscopy. mostly well-resolved signals could be assigned to stem from the surface-bound latter suggested bi- trifunctional silane linkage. Suspended-state spectroscopy thus proved well-characterized as proposed. To study recognition phenomena in presence CSP, 2D transfer NOESY investigations...
Tying up loose ends: Oligoamide thread molecules can spontaneously transform into open knots, whose terminal functional groups subsequently be chemically linked to form closed, cyclic knots (see scheme; left: threads; middle: knots; right: molecular X=N, C).
Cinchona-derived anion-exchange-type chiral selectors have been adapted and employed in countercurrent chromatography (CCC) for the separation of enantiomers N-derivatized amino acids 2-aryloxypropionic acids. The accurate optimization enantioseparation terms solvent system composition, pH values, ionic strength, CCC operating conditions was performed. A wide range mixtures evaluated. Successful resolutions were achieved systems such as ammonium acetate buffer/tert-amyl...
This article describes the synthesis, chromatographic characterization, and performance evaluation of analytical (100 x 4.6 mm id) semipreparative 10 monolithic silica columns with mixed-mode RP/weak anion-exchange (RP/WAX) surface modification. The RP/WAX were obtained by immobilization N-(10-undecenoyl)-3-aminoquinuclidine onto thiol-modified (Chromolith) a radical addition reaction. Their characterization Engelhardt Tanaka tests revealed slightly lower hydrophobic selectivities than C-8...
The chiral recognition mechanism of a cinchona alkaloid based selector for N-protected peptide enantiomers was investigated. A stationary phase derived from this employed liquid chromatographic enantiomer separations. It showed exceptionally high discrimination the (all-R)- and (all-S)-enantiomers dialanine (α = 20), while pronounced loss occurred upon insertion an additional alanine residue into backbone. This reduction enantioselectivity investigated in great detail by NMR spectroscopy...