Measurement uncertainty online course 11th run has successfully finished!

On May 09, 2024 the on-line course (MOOC) Estimation of measurement uncertainty in chemical analysis offered by the University of Tartu finished successfully.

Eventually altogether 1047 people registered from 104 countries. 655 participants actually started the course (i.e., tried at least one graded test at least once). The overall completion rate was 38%. The participation rate was this year 63%. The completion rate of the participants who started the studies was 61%, with 398 successfully finished participants. This result is quite stable during the 11 runs, showing also a small improving tendency compared to years after the COVID pandemic. This result can be considered good for a MOOC, especially for one that has quite difficult calculation exercises, which need to be done correctly with limited number of attempts for completing the course. All statistics during the 11 years can be found in the table below.

The participants 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 around 300 (!) (overall number of posts, both from participants and from teachers) and the forums are still active and posts are still coming in.

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

We plan to repeat this course again in Spring 2025 with a new breath in the course appearance!

Unified pH Scale – from Concept to Applications

On April 16, 2024, prof. Ivo Leito presented the topic of “Unified pH Scale – from Concept to Applications” at the 8th Baltic Electrochemistry Conference: Finding New Inspiration 2 (BEChem 2024), held in Tartu, Estonia. 

At the beginning of the presentation, Ivo gave a brief overview of why pH, a widely used value for expressing acidity, has serious limitations. Thus, it cannot be used to compare the acidities of solutions in different solvents, which can hinder the understanding of chemical, biological, environmental, and industrial processes.

A much more practical approach could be the usage of an absolute/universal pH, which would allow the comparison of acidities in different solvents. Thus, the main part of the presentation was focused on the theoretical and practical aspects of unified pH (pHabs). In recent years, our Acid-base Studies workgroup in the Analytical Chemistry Chair has worked extensively with the development and measurement of unified pH values for various systems in different solvents (liquid chromatography modile phases, electrocatalytic mixtures, strongly acidic solutions, etc). A differential potentiometry method for pHabs has been developed in the workgroup to obtain the unified pH values and has been now distributed to a number of groups in Europe in the framework of the UnipHied project.

For now, the unified pH has matured from a concept into a practical tool and has been accepted both by the European metrology community (Euramet) and by IUPAC. The unified pH could be utilized in various applications, such as liquid chromatography, catalytic systems, and acidity at the interfaces between phases. 

The presented research is largely the result of the EMPIR programme project 17FUN09 “UnipHied”.

Measurement Uncertainty online course: 1048 participants from 104 countries!

On Tuesday, March 19, 2024, the web course Estimation of Measurement Uncertainty in Chemical Analysis was launched for the eleventh time as a MOOC (Massive Online Open Course)!

Altogether 1048 participants from 104 countries are registered – the largest number of countries the course has ever had! In the map presented above, the yellow color marks the countries from where participants come. True, the map is coarse and some countries are small. Therefore, not all countries are visible. We are very happy, that we have 16 participants also from Ukraine this year. Slava Ukraini!

The entire course material is accessible from the web page https://sisu.ut.ee/measurement/uncertainty. The course materials include videos, schemes, calculation files, and numerous self-tests (among them also full-fledged measurement uncertainty calculation exercises). In order to pass the course, the registered participants have to pass six graded tests and get higher than 50% score from each of them. These tests are available to registered participants via the Moodle e-learning platform.

This course is run under the umbrella of the Estonian Center of Analytical Chemistry (https://www.akki.ee/) and forms a part of the measurements and chemical analysis related master programmes at UT: Applied Measurement Science (https://ams.ut.ee/) and Excellence in Analytical Chemistry (https://www.analyticalchemistry.eu/).

 

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. 

Read more here from the original post. 

Congratulations, Mari!

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 (pHabs) values of reversed-phase liquid chromatography (RPLC) mobile phases. The pHabs scale has the advantage over the conventional pH scale because pHabs values express acidity in terms of the thermodynamic activity of the solvated proton. Therefore, pHabs values are directly comparable between solvents/media of different compositions. At the same time, pHabs is convenient to use, as pHabs 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 pHabs 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 pHabs values of 78 mobile phases commonly used in RPLC, using around 300 individual ΔpHabs measurements between different mobile phases (see the “ladder” scheme below). This is, to the best of our knowledge, the most comprehensive collection of rigorous pHabs 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 ΔpHabs 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 pHabs values.

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

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…

LC-MS Validation online course 8th run has finished

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!

Anneli Kruve

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