The Chair of Analytical Chemistry at University of Tartu

Professor Peeter Tulviste Memorial Fund scholarship was awarded to Mari Tõrv

We are happy to announce that Mari Tõrv, Research Fellow in Analytical and Physical Chemistry and Associate Professor of Archaeology at the University of Tartu, was awarded the Professor Peeter Tulviste Memorial Fund scholarship.

Rector Toomas Asser and Dr. Mari Tõrv (photo: Andres Tennus)

Her interdisciplinary research combines archaeological heritage and analytical chemistry to gain insight into people’s past habits and practices. By applying both – humanities and natural sciences – she has improved our knowledge on human diet, diseases, and even funeral rites.

Besides research, she has been part of creating an infrastructure for preserving archaeological heritage digitally, founding the Estonian Association of Archaeologists, and developing the webpage eestijuured.ee to gather and promote the research about the ethnic history of Estonia during the last 11,000 years from the first hunter-gatherers to the digital nomads that we are today.

For Mari, the scholarship was a great recognition. “The scholarship proves that understanding cultural heritage is important in today’s crisis-torn world because it is the basis of our common identity.” She plans to use this scholarship to research further the culture of death by bringing together the analytical tools from biomolecular archaeology and social theory.

Mari obtained her PhD in archaeology in 2016 with joint supervision from the University of Tartu and the Christian-Albrecht University of Kiel. Since 2017, she has led the Collegium for Transdisciplinary Studies in Archaeology, Genetics, and Linguistics at the University of Tartu. In the Chair of Analytical Chemistry, she is part of the Archemy research group, where her expertise lays on stable isotope analysis of human and animal tissues.

The most comprehensive collection of rigorously measured pH values of mobile phases in reversed-phase liquid chromatography

During recent years, we have been engaged in extensive investigations of the unified pH (pH_abs) values of reversed-phase liquid chromatography (RPLC) mobile phases. The pH_abs scale has the advantage over the conventional pH scale because pH_abs values express acidity in terms of the thermodynamic activity of the solvated proton. Therefore, pH_abs values are directly comparable between solvents/media of different compositions. At the same time, pH_abs is convenient to use, as pH_abs values of aqueous solutions are equal to the respective conventional pH values.

This comparability is especially useful in RPLC, as mobile phases are mixtures of water with organic solvents in different ratios. Thus, it can be said that pH_abs is the best way of expressing pH if a rigorous comparison of pH between solutions in different solvents is needed.

As a result of our work, we have carefully measured the pH_abs values of 78 mobile phases commonly used in RPLC, using around 300 individual ΔpH_abs measurements between different mobile phases (see the “ladder” scheme below). This is, to the best of our knowledge, the most comprehensive collection of rigorous pH_abs values of RPLC mobile phases and has now been published as A. Heering, M. Lahe, M. Vilbaste, J. Saame, J. P. Samin, I. Leito. Improved pH measurement of mobile phases in reversed-phase liquid chromatography. Analyst 2024.

The ΔpH_abs values were measured by differential potentiometry, using potential differences in a symmetric cell with two glass electrode half-cells (see figure above) and almost ideal ionic liquid triethylamylammonium bis((trifluoromethyl)sulfonyl)imide [N₂₂₂₅][NTf₂] salt bridge with multiple overlapping measurements. The system of altogether 300 ΔpH values, pictured in the “ladder” scheme below, was anchored to the pH value of standard pH 7.00 aqueous buffer solution.

In addition, a simpler measurement method that uses double junction reference or double junction combined electrodes was tested and was found suitable for routine laboratories. The results show that the design of the junction is an important factor in deciding if the electrode can be used for unified acidity measurements. This is the first successful use of double junction combined electrodes filled with ionic liquid for the measurement of pH_abs values.

The article is featured in the themed collection Analyst HOT Articles 2024.

(This research was supported by grant PRG690 from the Estonian Research Council)

LC-MS Validation online course 8th run has finished!

On February 8, 2024 the on-line course (MOOC) LC-MS Method Validation offered by the University of Tartu finished successfully.

Eventually, altogether 1014 people registered from 109 countries. Around half of them, 508 participants actually started the course (i.e. tried at least one graded test at least once) and out of them 311 successfully completed the course. The overall completion rate was 31%. The completion rate of participants who started the studies was 61%. The completion rates of active participants (i.e. who started the course) seems to have stabilized at around 60%, which can be considered good. In addition, the overall completion rate is starting to increase again. In any case, there is some food for thought for us on how we could improve the overall completion rate…

At the same time, those participants who actually took part in the course, were very active and asked lots of questions. The questions were often very much to the point and addressed things that are really important to analysts in their everyday work. The course has several forums (general and by topic) and during the course period the overall number of forum posts was above 400 (!) (overall number of posts, both from participants and from teachers) and the forums are still active and posts are still coming in.

This active participation made teaching of this MOOC a great experience also for us, the teachers. The discussion threads gave a lot of added value to the course and some of them triggered making important modifications to the course materials, even during the course. Importantly, thanks to active participants, several mistakes were found and corrected in the course materials. As a result, the overall quality of the course improved.

We want to thank all participants for helping to make this course a success!

We plan to repeat this course again in Autumn 2024.

The Institute of Chemistry was recognized for improving the quality of education

The Institute of Chemistry received an award for its consistent and systematic efforts over the past three years to improve the quality of education.

One of the main goals was to develop students’ skills in specific subjects by changing teaching methods and involving students more actively in learning. For that, seminars were organized together with the teachers, which led to the realization that also the subjects of the lectures needed to be adjusted and coordinated with each other. Student feedback was used to improve courses, and the online learning platforms were updated. In parallel, the entire curriculum was revised.

Chemistry Master program director Edith Viirlaid and Vice-Rector Aune Valk

According to the Vice-Rector Aune Valk, the award recognized the Institute’s systematic and integrative approach to improving the quality of education. She emphasized the importance of consistent work for keeping the students engaged by active learning and motivating the students by making education more interactive and relevant to future careers. She also highlighted that there has already been a positive response from the students who appreciated the improvements.

In the University of Tartu, the award for improving the quality of education acknowledges a university institute, college, or department for their successful planning and implementation of activities that enhance the quality of learning. It is important that these initiatives include the collaboration between the faculty and students. Here is the original post in Estonian.

Measurement Uncertainty online course, March 19 – May 2, 2024: Registration is open!

The 2024 edition of the web course (MOOC) Estimation of Measurement Uncertainty in Chemical Analysis will be running from March 19 to May 2, 2024. Registration is now open!

The full course material (as well as the registration link) is accessible from the web page. The course materials include videos, schemes, calculation files, and numerous self-tests (among them also full-fledged measurement uncertainty calculation exercises) and examples. Almost all areas of analytical chemistry are addressed, ranging from simple volumetric operations and titrations to sophisticated instrumental analysis, such as determining pesticide residues by LC-MS. Efforts are made in the course to address also such uncertainty sources encountered in chemical analysis that are difficult to quantify, e.g. uncertainty due to possible interference effects (incomplete selectivity), analyte losses, etc.

In order to pass the course, the registered participants have to take six graded tests and get a higher than 50% score in every graded test. These tests are available to registered participants via the Moodle e-learning platform.

Participants who successfully pass the course will get a certificate from the University of Tartu. A digital certificate of completion is free of charge. A certificate of completion on paper can be requested for a fee of 60 euros.

You are welcome to distribute this message to potentially interested people!

The cultural heritage investigation workgroup published the first Tutorial Review article about lasers!

The analytical chemistry scientists (Dr Signe Vahur, Dr Anu Teearu-Ojakäär, Prof Ivo Leito) together with physicists (Dr Rünno Lõhmus, Dr Aleksei Treshchalov, Prof Jaak Kikas) from the Institute of Physics at the University of Tartu and conservation scientists at the Estonian Academy of Arts (Prof Hilkka Hiiop, MSc Käthi Niman), have published a new tutorial review article, “Laser-based analytical techniques in cultural heritage science – Tutorial review“ in the journal of Analytica Chimica Acta. The article is available here: https://doi.org/10.1016/j.aca.2023.342107.

Graphical abstract in the journal of Analytica Chimica Acta (https://doi.org/10.1016/j.aca.2023.342107)

This comprehensive collaboration article is significant for the cultural heritage investigation workgroup and the PRG1198 project team, which is currently developing a new laser-based MS system.

The main focus of this tutorial review is to give a simple and accessible overview of the physical background of different lasers, their parameters, and examples of applications in analytical techniques useful for the identification of components of various complex materials from a cultural heritage point of view. Besides conservators and cultural heritage scientists, this review may also interest researchers and students of other fields (e.g., material science, physics, chemistry, forensics, etc.) who wish to know more about lasers.

Congratulations on the ERC Consolidator Grant!

We are delighted to announce that the prestigious ERC Consolidator Grant 2023 was awarded to a former member of our Analytical Chemistry group, Associate Professor Anneli Kruve at Stockholm University!

The European Research Council (ERC) Consolidator Grant is aimed to support early-career researchers to consolidate their own independent research team or program over the next five years. We are very proud that this year one of the awardees was Anneli Kruve, Associate Professor at Stockholm University and head of the Mass Spectrometry Laboratory. In her research, she combines analytical chemistry with modeling and machine learning. The goal of the ERC funding is to support the research of her group on developing broader and more accurate methods to characterize and measure toxic chemicals in environmental samples.

Only a few percent of chemicals that cause the toxic activity of environmental samples are currently known. In this project, Anneli and her group will combine high-resolution mass spectrometry and machine learning to find novel toxic chemical structures, which enables focusing the toxicity research on chemicals that truly matter. Understanding the emission and transformation processes of toxic chemicals is a necessary step to decrease the chemical risks in the environment.

More information about the research performed by Anneli’s group can be found on the Kruve lab webpage.

Two new biomolecular studies of early farming by the Archemy group

Our Archemy group has recently published two major collaborative articles about the arrival and spread of early farming in NE Baltic.

Based on pottery lipid residue and dietary stable isotope analysis combined with zooarchaeological data and archaeobotanical studies, it was shown that farming arrived in the NE Baltic with migrating Corded Ware cultures in the early 3rd millennium cal BCE, but here this new subsistence strategy relied on stockbreeding rather than crop cultivation.

Early farmers in the NE Baltic were exploiting both domesticated and wild species, whilst the introduction of domesticates had little if any impact on local hunter-fisher-gatherer communities who remained true to their forager lifeways. There was no clear transition from foraging to farming in the 3^rd millennium cal BCE NE Baltic, instead we see separated communities and parallel worlds of local foragers and incoming early farmers practicing mixed economy. However, the lipid residue data in the wider Baltic context shows several regional variations in the arrival and spread of early farming practices.

Read full articles here:

Oras, E., Tõrv, M., Johanson, K, Rannamäe, E. et al. 2023. Parallel worlds and mixed economies: multi-proxy analysis reveals complex subsistence systems at the dawn of early farming in the northeast Baltic. R. Soc. open sci. 10230880230880. http://doi.org/10.1098/rsos.230880

Lucquin, A., Robson, H. Oras, E. et al. 2023. The impact of farming on prehistoric culinary practices throughout Northern Europe. PNAS. 120 (43) e2310138120. https://doi.org/10.1073/pnas.2310138120

The laureates of the Ann Mihkelson’s scholarship have been announced!

This year, the laureate of the Ann Mihkelson’s scholarship is Elisabeth Parman!

The scholarship was founded in 2011 by Anu Ebbe Mihkelson and its purpose is to support female scientists and doctoral students, especially chemists, with their research or supervision of master’s and doctoral students. We are happy to announce that this year, the scholarship was awarded to a young researcher from our Chair of Analytical Chemistry group – junior researcher/doctoral student Elisabeth Parman.

Congratulations from all of us to you, Elisabeth!

LC-MS Method Validation web course: 1013 participants from 109 countries!

Number of participants and countries updated on 22.11.2023!

On Tuesday, November 21, 2023 the web course LC-MS Method Validation was launched for the fifth time as a MOOC (Massive Online Open Course). There are ~~973~~ 1013 registered participants (the first time ever over 1000) from ~~107~~ 109 countries, ranging from Chile to China and from Australia to Iceland. And the number is still growing. The image below shows the countries where the participants come from.

This is a practice-oriented on-line course on validation of analytical methods, specifically using LC-MS as technique. The course introduces the main concepts and mathematical apparatus of validation, covers the most important method performance parameters and ways of estimating them. The LC-MS validation course is delivered by a team of 7 teachers, each with their own specific area of competence. This way it is expected to offer the best possible knowledge in all the different subtopics of analytical method validation.

The full set of course materials is accessible from the web page https://sisu.ut.ee/lcms_method_validation/. The course materials include videos, schemes, calculation files and numerous self-tests (among them also full-fledged calculation exercises). In order to pass the course, the registered participants have to take all tests and get higher than 50% score from each of them. These tests are available to registered participants via the Moodle e-learning platform. Participants who successfully pass the course will get a certificate from the University of Tartu.