Keemia bakalaureusetööde kaitsmised 2026

4.-5. mail toimus Chemicumis füüsika, keemia ja materjaliteaduse bakalaureuseõppekava keemia eriala lõputööde kaitsmine. Sel aastal jõudis oma töö eduka kaitsmiseni 16 väga tublit tudengit. Kaitstud tööde teemadering oli lai, ulatudes elektrokeemiast kuni biokeemiani. Kõik lõpetajad olid oma uurimistöösse põhjalikult süvenenud ja käsitlesid aktuaalseid teadusküsimusi. 

Anni Romandi

Tänavused kaitsmised tõid kaasa ka ühe olulise uuenduse – suulise kaitsmise korda muudeti nii, et akadeemilise arutelu osa pikendati 10 minuti võrra. See muudatus võimaldas nii retsensentidel kui ka kaitsmiskomisjonil põhjalikumalt käsitleda tööde tulemusi ning pidada sisukamat teaduslikku arutelu. Heameel on tõdeda, et kõik tudengid tulid selle väljakutsega edukalt toime ja kaitsesid oma lõputööd edukalt. 

Kaitsmiskomisjoni hinnangul paistsid tänavu eriliselt silma kaks tudengit, kellest üks (Anni) tegi oma uurimustöö Analüütilise Keemia Õppetoolis:

  • Anni Romandi ja
  • Elo Joandi.

Komisjon otsustas nende töid ja kaitsmisi eraldi tunnustada, sest mõlemad lõputööd olid eeskujulikult vormistatud ning nende autorid demonstreerisid suurepärast teemavaldamist ja argumenteerimisoskust.

Anni Romandi uurimistöö keskendus aluselisuse skaala valideerimisele ja täiendamisele atsetonitriilis. Nii teadustööd, tööstuslikke protsesse kui ka keemiasünteesi viiakse rohkesti läbi orgaanilistes lahustites nagu atsetonitriilis, mistõttu on usaldusväärsed aluselisuse ja happelisuse andmed sellistes keskkondades võtmetähtsusega. Töö käigus selgus, et seni kasutatud hapete ja aluste tugevuse skaalade vahel esineb küll väike nihe, kuid see ei mõjuta enamasti nende praktilist kasutamist eelpool mainitud rakendusvaldkondades. Lisaks määrati täpsemad väärtused mitmele väga tugevale fosfaseenalusele, mis aitavad tulevikus usaldusväärsemalt ennustada ainete käitumist erinevates keemilistes protsessides. Töö juhendajad olid PhD Märt Lõkov ja professor Ivo Leito. 

Elo Joandi uurimistöö keskendus uudse biosensoripõhise katseplatvormi arendamisele, mis võimaldab uurida serotoniini retseptorite ja nendega seonduvate ühendite vastastikmõju. Töös näidati, et bakuloviiruse nanoosakestel põhinev süsteem võimaldab usaldusväärselt jälgida retseptori aktiivsusega seotud muutusi ning hinnata erinevate keemiliste ainete toimet. Sellised meetodid aitavad paremini mõista närvisüsteemi signaalülekande mehhanisme ning pakuvad uusi võimalusi farmakoloogiliste sõelkatsete läbiviimiseks. Töö juhendajad olid PhD Sergei Kopantšuk ja PhD Santa Veikšina. 

Equilibrium Brønsted acidity measurements in 1,2-difluorobenzene

Table 1

We are pleased to share our latest open-access article titled “Acidity scale in 1,2-difluorobenzene” by John Paulo Samin, Helerin Roomet, Märt Lõkov, Sofja Tshepelevitsh, Jaan Saame, Agnes Heering, and Ivo Leito, published in ACS Omega (DOI: 10.1021/acsomega.6c02089).

In this work, we established equilibrium Brønsted acidity measurements in 1,2-difluorobenzene (1,2-DFB) in terms of pKa values measured by UV-vis spectrophotometry and unified pH (pHabs) values measured by differential potentiometry.

The pKa scale in 1,2-DFB spans 15 orders of magnitude. The pKa values were determined for 137 acids, 33 of which were directly measured (see Table 1). The remaining values were estimated using correlation equations relating pKa values in other solvents (acetonitrile and 1,2-dichloroethane) to those in 1,2-DFB. The pKa scale was anchored to the computational pKa values of 9 acid compounds.

Furthermore, an experimental unified pH scale spanning more than 10 orders of magnitude was established. The scale was aligned to the aqueous pH scale, assigning pHabsH2O values to the buffer solutions of 22 acids ranging from −0.6 to 10.0 (see Table 2). The potentiometrically measured pHabsH2O values showed good agreement with the values independently calculated from experimental pKa values anchored to computational reference values, demonstrating the solid foundation of the underlying theory.

These results open the possibilities for quantitatively describing and measuring acid−base processes in 1,2-DFB, including potentiometric and UV−vis spectrophotometric pHabsH2O measurement.

(This research was supported by grant PRG2557 from the Estonian Research Council and TK210 from the Estonian Ministry of Education and Research.)

Table 2

Visting lecturers – Dr Burcu Binici and Dr Alons Lends

Dr Burcu Binici giving a lecture on metrology

In April, our group hosted two experts who gave lectures on their topics.

First, on April 14-15, Dr Burcu Binici, a specialist at TUBITAK UME (the National Metrology Institute of Türkiye), presented materials on CRMs in the chemistry field to students in the Metrology in Chemistry course. The listeners had the opportunity to broaden their understanding of CRM, RM production, and the requirements for that.

Then, on the weekend of April 17–18, Dr Alons Lends led an intensive NMR course. He is currently working at the Latvian Institute of Organic Synthesis and has extensive experience in various NMR applications. During his course, students and the members of the Analytical Chemistry group learned more about NMR in biomolecular studies and materials science.

 

Dr Alons Lends giving a lecture on NMR

Ahmed, a student of the EACH (Excellence in Analytical CHemistry) Master’s program, said about the lectures: “This is what makes EACH special: learning directly from experts. One of the best things about the EACH program is that it brings experts to teach specific parts of your curriculum or to give you a deep dive into fields you already know. That’s what makes you feel very comfortable, as you can get very good answers to your questions from experts.”

The Cultural Heritage Research Group started with a new PRG project!

In January 2026, the cultural heritage research group – in collaboration with physicists, material scientists, conservators, and IT specialists – launched a challenging new five-year Personal Research Funding Team (PRG) project, led by Dr Signe Vahur. The main goal of the PRG3112 project is to develop a novel, portable, automated laser ablation sampling probe. This tool will enable minimally destructive stratigraphic and imaging analysis of artefacts directly on the object under ambient conditions. In the future, the probe could be coupled with various analytical devices (MS, Py-GC-MS, and FORS) and sampling containers.

We will keep you updated on the progress of this demanding and exciting project!

The research team remains largely the same as in our previous project.

The main members of the PRG team: team leader Dr Signe Vahur (in the centre), from left Dr Aleksei Treshchalov, Prof. Hilkka Hiiop, Dr Anu Teearu-Ojakäär, Dr Rünno Lõhmus and specialist Martin Leissoo.

New article on ancient dietary analysis by Archemy Group

The Archemy group is happy to share the latest article published in the Journal of Archaeological Method and Theory – Food Equality: Multiproxy Biomolecular Dietary Analysis Shows Unstratified Foodways Among Protohistoric E Baltic Communities.

The paper is crucial milestone for the group serving as an excellent example of collaborative analytical work combining all the multiple expertises of the Archemy.  The results do not only challenge our previous understanding of Conversion period social dietary practices in Estonia, but will serve as a key-reference for future multi-proxy and multi-method dietary analysis. The main findings include:

*There was no major dietary difference between men, women and children in the 12th-13th century AD Pada community: all had equal access to food sources!

*Meat-based foods were preferred in burial ritual contexts, whilst plant-based foods formed majority in daily food consumption.

*No single proxy approach or method can reveal the full spectrum of ancient dietary practices.

Many thanks to all the amazing collaborators who contributed to this work!

 

New publication: determining water content in lignin using ATR-FTIR

Shrikant performing the FTIR measurements

We are delighted to share that our latest article titled “A quantitative approach to determine water and moisture content of different types of lignin using attenuated total reflectance Fourier transform infrared spectroscopy combined with partial least squares regression” has been published in the journal of Biofuels, Bioproducts and Biorefining (Volume 20, 2026). The article was authored by Shrikant Shivaji Pawade, together with Dr Martin Vilbaste, Andres Siiman, Dr Lauri Toom, Associate Professor Koit Herodes, and Professor Ivo Leito. The article is Open Access and available online; click here to access it.

The study presents a quantitative methodology for determining water and moisture content in diverse lignin types using ATR-FTIR spectroscopy combined with partial least squares regression, with vapourisation–coulometric Karl Fischer titration (vap-C-KFT) and gravimetric methods used as reference techniques. In addition, the work introduces a sigmoid curve approach to temperature optimisation for vap-C-KFT and evaluates sampling and modelling uncertainties, thereby providing practical insights for reliable lignin characterisation. The robustness of the method was assessed by validation against vap-C-KFT, oven drying (7 h and 48 h), and freeze-drying, utilising diverse lignin types (Kraft, Dealkaline, and Lignova Fibenol) and achieving RMSEP values ranging from 0.33 to 1%.

The results demonstrate that ATR-FTIR combined with chemometrics modelling can provide a rapid, simple, and cost-effective alternative to conventional methods, while maintaining good accuracy across diverse lignin types.

A new article about a developed laser ablation-based mass spectrometric system for the analysis of cultural heritage materials has now been published!

The Cultural Heritage research group, as part of this year-end PRG1198 research project, has published an open-access article titled “Laser ablation APCI-HRMS method for the analysis of cultural heritage materials” by Anu Teearu, Martin Leissoo, Rynno Lohmus, Alexey Treshchalov, Tõiv Haljasorg, Victor Augusto Xavier da Silveira, Hilkka Hiiop, and Signe Vahur in the Journal of the American Society for Mass Spectrometry. The article is available here.

Graphical Abstract for the publication

This research article highlights a novel 355 nm optical fibre-coupled laser ablation (LA)-APCI-FT-ICR-MS system, developed for direct, controllable, rapid, and accurate analysis of organic materials from the solid surface of an artefact under ambient conditions with minimal surface damage and without the need for sample removal or sample preparation for the analysis. In this study, the effectiveness and capabilities of the developed LA-APCI-HRMS system for analysing five aged mock-up materials (copper resinate, Prussian blue oil and egg tempera paints, lead white oil paint and matte dammar varnish) and the blackish-brown material from an ointment jar from a 16th-century shipwreck were investigated. The results can be read in the article.

The PRG1198 project team has done excellent work over the past five years, culminating in a working laser-based HRMS system. The same team will begin next year with a new project, and we will continue to keep you updated on all new developments.

In the photo, the main members of the PRG team: team leader Dr Signe Vahur (in the centre), from left Dr Aleksei Treshchalov, Prof. Hilkka Hiiop, Dr Anu Teearu-Ojakäär, Dr Rünno Lõhmus and specialist Martin Leissoo.

 

Our LC-MS validation activities at the IUPAC-DSM LC-MS validation workshop

Riin Rebane, Asko Laaniste and Ivo Leito participated on 10-11.12.2025 in the Joint IUPAC-DSM Workshop on LC-MS method validation and performance, organised jointly by the IUPAC’s Division of Analytical Chemistry and the Mass spectrometry division (DSM) of the Italian Chemical Society.

Riin presenting

Riin presented the opening keynote of the event titled “Principles of method validation”. Her presentation reframed LC-MS method validation as a risk-management process rather than a checklist of validation characteristics. By zooming out to the method’s intended purpose, each validation characteristic is linked to the specific risks it is designed to control. This view allows to build evidence that the method performs reliably under real-world conditions and is truly fit for purpose and produces results with known confidence.

 

 

Ivo’s talk “What are the issues encountered in the real world? Lessons learned form an online validation course” presented an analysis of the main issues brought up by the participants of the nine editions of an online LC-MS method validation course (https://sisu.ut.ee/lcms_method_validation/). The analysis of 2640 course forum posts and 336 participant feedback submissions revealed that practitioners struggle a lot with calculations and spreadsheet software, which diverts effort from real “analytical hemistry” issues.  

Asko leading the ValChrom session

Asko’s session “ValChrom open-access online validation software” was a workshop in the true sense of the word: a hands-on session on the online validation software ValChrom developed at UT. Participants had instant access to the software freely available in web and demo materials. Asko walked them through the whole process of ValChrom from start to finish, from defining analytes to customizing experimental plan with AI and finishing with automatically generated DOCX file with the whole validation data in it. ValChrom’s Design of Experiements (DoE) capabilities were also covered and it was nice to see that throughout the two days a big number of presentations also involved DoE one way or another, indicating a rising need for such tools.

All in all, the contributions of our team were highly appreciated, indicated by numerous questions, both during sessions and (especially) during coffee breaks.

 

 

This year’s recipients of honorary decorations have been announced

Ivo Leito and Koit Herodes were awarded honorary decorations by the University of Tartu.
Professor Ivo Leito received the University of Tartu Grand Medal, and Associate Professor Koit Herodes received the University of Tartu Badge of Distinction. 

Ivo and Koit

Ivo, our Professor of Analytical Chemistry, has been recognised with the university’s highest internal honour for services of particular value. The Grand Medal highlights Ivo’s internationally renowned scholarship that blends high-level fundamental research with metrological precision and innovative teaching. His excellent leadership and mentorship have shaped generations of chemists and strengthened the standing of analytical chemistry at the University of Tartu and beyond.

Koit, our Associate Professor of Analytical Chemistry, has been awarded the University of Tartu Badge of Distinction in acknowledgement of his dedicated service to the University. Koit’s contributions to analytical chemistry spanning from research to teaching have had a strong positive impact on our group’s scientific excellence and student experience.

The decisions were made by the University of Tartu senate on October 31. The University will present this year’s honorary decorations at a ceremony on 21 November at 16:00 in the University of Tartu assembly hall. More information and the other recipients can be found here. 

Please join us in congratulating Ivo and Koit on these well-deserved recognitions!

ICNTS25 – Gathering people without targets!

Having no predefined targets in your sample isn’t always a drawback. The International Conference on Non-Targeted Screening (ICNTS) demonstrated how omitting targets in mass spectrometry analysis can reveal a broader and more nuanced picture of the chemical space. 

Pilleriin presenting at ICNTS25

From October 13-16, for the fifth time, non-targeted screening experts from around the world gathered in Erding, Germany, to share their latest research and exchange ideas. The event showcased cutting-edge developments across diverse fields, including metabolomics, foodomics, water analysis, harmonisation, and prioritisation. 

Representing our group, Pilleriin Peets, Principal Investigator of the Chemical Space & Omics group, gave an oral presentation on compound class vectors for comparing metabolomics samples. Her talk was part of the computational mass spectrometry session, chaired by Emma Schymanski, who also gave a keynote on “Data Handling in a Modern NTS World.” 

The ICNTS once again proved that by embracing the unknown, researchers are expanding the boundaries of chemical analysis and opening new doors for discovery. Whether in environmental science, health, or food safety, the power of non-targeted approaches lies in their ability to reveal what we didn’t even know to look for. 

Learn more about the conference and the community: https://afin-ts.de/icnts25/