Pre- and post-acquisition procedures were developed for enhancing the lateral resolution in elemental imaging by LA-ICP-MS. Signal deconvolution of the pulse response peaks generated by a low-dispersion LA cell enables higher repetition rates while permitting single pulse isolation, thus ensuring that the spatial information associated with each pulse remains accessible. When correctly implemented, the spatial resolving power of the methodology surpasses that of any other in LA-ICP-MS, as a lateral resolution below the beam dimensions can be obtained.
COBISS.SI-ID: 5695258
Aromatics are important atmospheric pollutants and represent considerable hazard for our ecosystem; a powerful tool for the assessment of their impact on the environment was developed. The study revealed that remote biotopes might be the most damaged by wet urban guaiacol-containing biomass burning aerosols. Revising the recent understanding of atmospheric chemistry, which is mostly concerned with radical mechanisms, this is mainly due to electrophilic nitrogen-containing reactive species.
COBISS.SI-ID: 37870853
Through a rational approach, the carboxamido moiety of tetracyclines (an important structural feature for their bioactivity) was introduced into the chelocardins, which are atypical tetracyclines with an unknown mode of action. A broad-spectrum antibiotic lead was generated with significantly improved activity, including against all Gram-negative pathogens of the ESKAPE panel. Since the lead structure is also amenable to further chemical modification, it is a platform for further development through medicinal chemistry and genetic engineering. The members of the Analytical Chemistry Laboratory at the National institute of chemistry have contributed to the work with structure elucidation of the newly synthesized compounds using mass spectrometry.
COBISS.SI-ID: 4486520
We developed an electrochemical sensor based on carbon paste modified with silver nanoparticles (AgNPs) for measuring low concentrations of nitrite ions. The carbon powder was decorated with AgNPs and a hydrophobic ionic liquid served as the binder. It has been shown that AgNPs exhibit a favorable electrocatalytic effect on the nitrite oxidation. For optimal electroanalytical performance the sensor was conditioned via silver oxidation/reduction potential cycle revealing a linear voltammetric response in a wide concentration range of 0.05 - 1.0 mmol L-1, limit of detection of 3 μmol L-1 and excellent repeatability with RSD of 0.3%.
COBISS.SI-ID: 5639706
Droplet-based liquid–liquid extraction in a microchannel was studied, both theoretically and experimentally. A full 3D mathematical model, incorporating convection and diffusion in all spatial directions along with the velocity profile, was developed to depict the governing transport characteristics of droplet-based microfluidics. The finite elements method was used to solve the set of differential equations regarding conservation of moment, mass and solute concentration in a two-domain system coupled by interfacial surface of droplet-based flow pattern. The model was numerically verified and validated online by following the concentrations of a solute (azobenzene) in two phases within the microchannel. The relative azobenzene concentration profiles in a methanol/n-octane two phase system at different positions along the channel length were retrieved by means of a thermal lens microscopic (TLM) technique, which was developed further and optimized for detection in microfluidic systems, based on our previous theoretical and experimental work. TLM gave results of high spatial and temporal resolution. Very good agreement between model calculations and online experimental data was achieved without applying any fitting procedure to the model parameters.
COBISS.SI-ID: 1536245187