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.
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!
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.
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.
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.
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.
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!
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.
With his opponent Prof. Nicole Pamme, who is focused on Lab-on-a-Chip devices, they gave a memorable and enjoyable PhD defence at the Institute of Chemistry. Prof. Nicole Pamme holds a chair in Analytical Chemistry at Stockholm University. During the defence, her excellent general science-to-market questions, as well as detailed questions specific to chemistry and material science, helped the audience to gain a clear understanding of the need for research, practical applications and how everything was also achievable from a technological perspective.
Indrek’s dissertation has given valuable new insights into the simple to use on-site chemical analysis tests.
Picture of the fully assembled Biotin test developed in this work.
What if advanced chemical testing could be done anywhere – right where the need arises, without a laboratory?
Traditional high-quality chemical analyses often require complex equipment, trained personnel, and significant time, creating a need for faster, more accessible solutions. In Indrek`s thesis, new on-site chemical analysis tests were developed that not only simplify testing but also aim to achieve higher analytical performance than existing portable methods. These tests were developed using a novel screen-printed particle-based method that is fast, low-cost, and potentially scalable for mass production.
The applications of functional prototypes included monitoring biotin levels in urine and measuring different metal cations in various water samples, even in challenging agricultural nutrient solutions containing strong chelating agents.
Separation of biotin and its metabolites on the printed microfluidics chip. The chip has been visualised by spraying it with a solution of p-dimethylaminocinnamaldehyde (p-DACA) in ethanol and sulphuric acid.
These patented innovations are laying the foundation for highly capable, mass-producible diagnostic tools that can enable faster, more accurate decision-making in environmental monitoring, healthcare, and agriculture.
During his PhD studies and research, Indrek was supervised by Dr Hanno Evard and by Prof. Ivo Leito. Indrek’s special thanks go to the main supervisor, Dr Hanno Evard, who had been a constant source of guidance, encouragement, and support. From countless discussions and brainstorming sessions to planning and problem-solving, Hanno’s insight and commitment had been central to this work.
On the 27th of August, Marta-Lisette successfully defended her dissertation “Exploring the basicity of phosphanes and related compounds”, marking an important milestone in her academic journey. Her dissertation has given valuable new insights into the basicity and preparation of phosphanes and related compounds. The defence was conducted in an atmosphere of professionalism and collegiality, with a thoughtful exchange of ideas and perspectives.
Special thanks go to the opponent, Dr Martin Smith from Loughborough University, whose insightful and well-chosen questions guided the discussion. His role helped ensure the defence was not only rigorous but also smooth and engaging.
It was a proud moment for Marta (and her supervisors) and a wonderful occasion for everyone who has supported her throughout this process. Congratulations to her on this achievement!
“This comprehensive review brings together technical depth and years of personal lab experience, shaped by long hours at the bench, countless peer discussions, and valuable lessons learned along the way. It offers a detailed, practice-oriented guide to how derivatization can dramatically improve analyte retention and ionization in LC-MS, especially for challenging amino compounds. The article dives into reagent selection, method optimization, and real-world troubleshooting – tools I wish I’d had starting out.”
This work was supported by the Estonian Research Council grant PUT1589, and by the Estonian Ministry of Education and Research (TK210). The research was conducted using the Estonian Center of Analytical Chemistry, funded by the Estonian Research Council (TT4).
