Research and Development of Analytical Methods and Procedures
P1-0153
Duration: 1.1.2020 - 31.12.2027
Head:
prof. dr.
Pompe Matevž
Research programme is focused on several research directions within the broad area of analytical chemistry. These directions are described in the following sections.
a) New analytical methods and approaches
Recently, the research and development of new analytical methods is influenced by the growth of industrial production capacities, the development of new materials as well as the more strict demands for quality control and protection of human health and environment. The research will be focusing on all steps of an analytical method, from the sample preparation to the quantification and the interpretation of results. Recent trends in the developments of analytical chemistry will be followed, such as the use of coupled techniques for analysis of complex samples, trace analysis, speciation, studies of electrochemical processes, new separation and pre-concentration methods and the quality control of the obtained results. New methods will be developed in the fields of spectroscopic (MS, ICP, AAS, ASV, FIA, IC), separation (GC, HPLC, UPLC, 2-D HPLC), electrochemical (voltammetry, sensors) and combined hyphenated instrumental techniques (GC-MS, HPLC-MS-MS, EC-FIA, EC-LC, spectroelectrochemistry). In addition, new methods for sample pre-treatment and pre-concentration (dialysis, solid phase extraction/microextraction) will be developed and numerical methods and programming (modelling of retention characteristics, virtual instruments) will be employed.
b) Research and applications of modern materials in chemical analysis
Recent developments of modern electroanalysis are focused on miniaturization and improved selectivity of electrode materials. In voltammetry, traditionally used Hg electrodes were replaced by new electrode materials, such as Au, C, Pt, Sn and Bi. In particular, different carbon modifications (carbon paste, glassy carbon, boron-doped diamond electrodes, and graphene structures) show numerous advantages over the classical metal electrodes. Properties of new and modified electrodes are evaluated by different voltammetric techniques (CV, SWV, DPV, AdV, ASW, CA) and their response to various analytes. Electrochemical reaction mechanisms are investigated, including those of antioxidants and anti-cancer therapeutic agents. Newly developed electrodes and sensors are tested for determination in real samples and in flow-through analytical systems. Electrochemical methods are combined with surface analysis methods (SEM, TEM, AFM, EDX), that will supply the necessary structural information about the electrode surfaces.
The recent progress of various new nanomaterials and their expanding production and diversity of applications requires a development of new analytical methods for their determination and characterization as they are gradually becoming a source of environmental pollution. Analytical methods are developed for the determination of nanoparticles in animals and plants, e.g. CeO2, TiO2, and Ag. Research is also based on LA-ICP-MS, which enables the determination of the distribution of nanoparticles in the tissues of living organisms. However, some nanomaterials can be used as efficient cleaning agents of contaminated industrial water, especially for adsorption of toxic heavy metals (Cd, Cr, Mo, As, etc.). New types of nanomaterials are developed and their physicochemical mechanisms are studied for the purpose of wastewater contaminant removal, evaluated by ICP-MS, ICP-OES, ET-AAS, AAS, AES, as well as electrochemical techniques.
An interesting biomaterial with versatile applications are fungi. Their cultivation is often accompanied by the production of large amounts of mycelium, which remains unused. We test the mycelium to develop applications for (industrial) wastewater treatment, contaminated with various heavy metals. Using spectroscopic techniques, we develop suitable procedures to prepare the samples for more efficient absorption of toxic metals (e.g., Pb, Cr, Cu, and Cd), and for potential applications for bio-remediation procedures.
c) Characterization of biologically important molecules
Determination of biological molecules is of outmost importance as they are one of the most important compounds for the functioning of living organisms. Determination of low molecular weight molecules in complex samples represents a substantial challenge, especially when they are present in very low concentrations; a typical example are biomarkers. Very precise analytical methods are needed to study the small variations in the structure of biological macromolecules, such as monoclonal antibody isoforms or supercoiled plasmid DNA topoisomers.
One segment of our research is focused on the analysis of therapeutic glycoproteins, in particular, the determination of their glycosylation pattern by implementing 2D-HPLC techniques, combining hydrophilic interaction chromatography (HILIC), ion chromatography (IC), reverse phase chromatography (RP), size exclusion chromatography (SEC), and others. Applications of mixed mode chromatography are also developed, as well as new stationary phases focusing on convective based supports, such as monoliths with properly designed functional groups. Different microstructures are tested that affect the mobility of large macromolecules in the separation. Similar methodology can be further extended to medicinal polysaccharides, plasmid DNA, viruses, and other macromolecular assemblies such as microvesicles.
d) Environment and food safety
Environmental pollutants (inorganic and organic compounds; nanoparticles, microplastics) are usually present in the environment in low concentrations, but they nevertheless exhibit an adverse effect on the ecosystems and on human health. Monitoring of the pollutants in the environment is necessary to determine their residence time; typical processes, reactions, and transformation products; their availability for microorganisms; as well as the exposure of plants, animals, and humans to the pollutants and their transformation products. They have to be monitored in all environmental compartments: atmosphere, hydrosphere, soil and sediments, living organisms, as well as in drinking water and foodstuffs, which represent the main exposure route for humans. To this purpose, it is essential to develop sensitive and accurate analytical methods combined with modern sample preparation approaches that produce as little as possible of waste products.
Part of the research programme focuses on the development of microextraction methods for isolation of different groups of environmental contaminants, especially emerging environmental pollutants (benzotriazoles, residuals of pharmaceuticals and illicit drugs, artificial sweeteners, compounds from personal care products, plastic mass additives etc.), currently important groups of pesticides (e.g. neonicotinoids), as well as persistent organic pollutants (PAH, PCB) and oil products. Microextractions are applied for their extraction from liquid and solid environmental samples. At the same time, suitable analytical methods for determination of contaminants of interest are developed (GC-MS, LC-MS/MS). The developed methods are also applied to determine the contaminants in foodstuffs, e.g. due to migration of plastic mass additives to the food. Effectiveness of remediation technologies on the environment are monitored, such as the effectiveness of degradation of contaminants from oil in the remediated soil after the removal of heavy metals with EDTA. The efficacy of the new remediation strategies for pollutant removal from wastewaters are researched and transformation products identified, such as during the sorption to the functionalized active carbon or electrooxidation.
Advanced methods for sample preparation and analysis are also applied to the tropospheric research, specifically to formation of secondary organic aerosols and the role of until now underestimated oxidation mechanisms, e.g. the influence of singlet oxygen produced on the black carbon particles in the atmosphere.
Scientific and socio-economic significance of research
As a research group at the University of Ljubljana, we are aware that an important socio-economic goal of our programme is the further development of the research field analytical chemistry, since university education is at all levels inextricably linked to research excellence. Only a close connection between research and education contributes to the training of specialized personnel and thus develops basic and applied knowledge necessary for the existence and progress of the profession. Knowledge is transferred to younger generations by actively involving students of all levels of study in the work of the research group. The majority of graduates, master students and doctoral students who have completed their studies in chemistry at the UL FKKT, successfully use the acquired knowledge in the field of analytical chemistry in industry or at research institutions at home and abroad. Several university textbooks written by some of the group's collabolators also testify to the activities in this field.
The socio-economic importance of our research is also reflected in the research related to the development of products with high added value, which improves the competitiveness of our economy and contributes to the development of Slovenia. Research in this area uses the results of our basic research and gives them practical and commercial value. In this area, our research is primarily focused on solving the problems of safe and healthy food (toxins, carcinogens, allergens, antioxidants, flavours, etc.) and the development of pharmaceuticals, which will contribute to technological progress in these areas in Slovenia and beyond.
Our research in the field of environmental protection is in accordance with the constitutional right to live in a healthy environment for all citizens of the Republic of Slovenia. Through research on the transfer and deposition of contaminants in soil and sediments, in surface and groundwater, in the atmosphere and also in food, we want to accumulate the necessary knowledge that will enable the adoption of legal restrictions to ensure the aforementioned constitutional right. We research groups of emergent pollutants for which legal limits in drinking water, surface water, and soil have not yet been set either in Slovenia or elsewhere. Therefore, knowledge of their behaviour in the environment is particularly important. We would also like to emphasize our research in the field of aerosol particles, which significantly contribute to air pollution and its health and climate consequences.
