UnipHied EMPIR Network at Baltic Electrochemistry Conference 2018

On Nov 05, 2018 Ivo Leito gave a presentation Unified pH about the pan-European research network of fundamental pH Research UnipHied (www.uniphied.eu) at the 7th Baltic Electrochemistry Conference organized by the University of Tartu.

The presentation started with explaining the need for the experimental realization and measurement capability of unified pH (pHabs). Thereafter the current state of art of measuring pHabs values was described and finally, some first exemplary results were highlighted.

The presentation created a lot of interest from the participants and roughly as many questions were asked as for the other four presentations of the same session put together!

As of now, it is not possible to compare pH values of solutions made in different solvents, as every solvent has its own pH scale. This situation is highly unfortunate, since it causes confusion and inaccuracies into many fields, extending far beyond the specific field of acid-base chemistry. Examples are industrial catalytic processes, food chemistry, liquid chromatography, etc.

The central aim of the UnipHied network is to establish at international level measurement capability of pHabs values that would be applicable also at routine laboratory level. The two key activities for achieving that are creating a reliable method for the experimental or computational evaluation of the liquid junction potential and between aqueous and non-aqueous solutions and developing a coherent and validated suite of calibration standards for standardizing routine measurement systems in terms of pHabs values for a variety of widespread systems (e.g., industrial mixtures, soils/waters, food products, biomaterials).

The partners of the UnipHied network are LNE (France, coordinator), BFKH (Hungary), CMI (Czech Republic), DFM (Denmark), IPQ (Portugal), PTB (Germany), SYKE (Finland), TÜBITAK-UME (Turkey), Freiburg University (Germany), ANBSensors (United Kingdom), FCiencias.ID (Portugal), UT (Estonia, initiator).

UnipHied is funded from the EMPIR programme (project 17FUN09) co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.

 

UT analytical chemistry education activities at EcoBalt 2018 Conference

On Oct 26, 2018, Ivo Leito gave a presentation titled “Analytical chemistry education activities at University of Tartu” at the EcoBalt 2018 conference in Vilnius, Lithuania.

The presentation contains information about the online courses LC-MS Method Validation and Estimation of Measurement Uncertainty in Chemical Analysis, as well as the recently published tutorial reviews (Validation I, Validation II, LoD I, LoD II) that form the basis of the LC-MS Method Validation course.

The presentation also addresses the international master’s programmes Applied Measurement Science and Excellence in Analytical Chemistry at the University of Tartu.

The last part of the talk is devoted to the Eurachem 2018 General Assembly and Workshop that will take place in Tartu on May 20-21, 2018. The topic of the workshop is “Validation of targeted and non-targeted methods of analysis”.

 

Milestone in catalysis research: approaching sub-ppm-level asymmetric organocatalysis

Recently our group had the pleasure of participating in a cutting-edge endeavor: characterizing the acidity of some extremely efficient strongly acidic organocatalysts. In the case of the Mukaiyama aldol reaction, the best of them (1) worked at low ppm to sub-ppm level, (2) gave excellent yields and (3) high enantiomeric selectivity as well as (4) turnover numbers (TON numbers) of hundreds of thousands.

The extent to which these four features occurred together in the same catalyst was so remarkable that the results were published in one of the most prestigious journals in chemical sciences: Nature Chemistry 2018, 10, 888-894.

The extremely demanding acidity measurements were performed by Dr Karl Kaupmees. The whole research was led by the group of professor Benjamin List – a worldwide known guru in the field of strongly acidic catalysts working at the Max-Planck-Institut für Kohlenforschung.
These results are expected to open new avenues in the development of powerful new organocatalysts.

(Photo by Andres Tennus: Karl doing acidity measurements in a glovebox under anhydrous conditions)

From Advancements in Separation Technology to Fundamental Basicity Studies

This is the range of topics addressed on Aug 31, 2018 as PhD dissertations addressing these topics were defended at UT Institute of Chemistry by Sofja Tšepelevitš and Märt Lõkov.

Sofja Tšepelevitš (right on the photo) in her thesis titled Experimental studies and modeling of solute-solvent interactions evaluated and developed approaches for modeling intermolecular interactions in solutions and the resulting macroscopic solute properties. The applicability of the COSMO-RS method to modeling hydrogen bonding in solution was evaluated. COSMO-RS was also evaluated for its ability to predict solvent-solvent extraction. An interesting and novel issue addressed in her work besides conventional structure based property prediction was the possibility to predict liquid-liquid partitioning of solutes with unknown structure.

The thesis of Märt Lõkov titled Basicity of some nitrogen, phosphorus and carbon bases in acetonitrile is focused on obtaining high-quality basicity data (pKa data) of bases of most diverse families and rationalizing their behavior and revealing structure-basicity relationships. Nitrogen bases (N-heterocycles), phosphorus bases (halogen-substituted phosphanes) and carbon bases (substituted pentafulvenes) were included in the work.

Congratulations to both of you!

Pan-European Network of Fundamental pH Research: UnipHied

Initiated by our group, the pan-European research network of fundamental pH Research UnipHied started in May 2018.

Why is such network needed? As of now, it is not possible to compare pH values of solutions made in different solvents, as every solvent has its own pH scale. This situation is highly unfortunate, since it causes confusion and inaccuracies into many fields, extending far beyond the specific field of acid-base chemistry. Examples are industrial catalytic processes, food chemistry, liquid chromatograpy, etc. The central goal of UnipHied is to overcome this situation by putting the new theoretical concept of the recently introduced unified pHabs scale on a metrologically well-founded basis into practice.

The most important specific objectives of UnipHied are (1) to develop and validate a reliable and universally applicable measurement procedure that enables the measurement of pHabs; (2) to create a reliable method for the experimental or computational evaluation of the liquid junction potential between aqueous and non-aqueous solutions; (3) to develop a coherent and validated suite of calibration standards for standardizing routine measurement systems in terms of pHabs values for a variety of widespread systems (e.g., industrial mixtures, soils/waters, food products, biomaterials).

The first version of the pHabs measurement procedure has been created by Agnes Heering (Suu) in the framework of her PhD thesis. The main experimental difficulty is evaluation of the liquid junction potential (LJP), which will be thoroughly addressed by UnipHied. The first important steps towards this goal have very recently been made and published as two back-to-back papers: Angew. Chem. Int. Ed. 2018, 57, 2344–2347 and Angew. Chem. Int. Ed. 2018, 57, 2348–2352
The key achievement described in the papers is finding an ionic liquid, namely [N2225][NTf2], that can be used as salt bridge electrolyte and has such properties that two out of three main sources of LJP are eliminated.

The partners of the UnipHied network are LNE (France, coordinator), BFKH (Hungary), CMI (Czech Republic), DFM (Denmark), IPQ (Portugal), PTB (Germany), SYKE (Finland), TÜBITAK-UME (Turkey), Freiburg University (Germany), ANBSensors (United Kingdom), FCiencias.ID (Portugal), UT (Estonia).

UnipHied is funded from the EMPIR programme (project 17FUN09) co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.

 

Comparative validation of amperometric and optical dissolved oxygen sensors

A comprehensive comparative validation for two different types of dissolved oxygen (DO) analyzers, amperometric and optical, together with estimation of measurement uncertainty is presented in the recently published article I. Helm, G. Karina, L. Jalukse, T. Pagano, I. Leito, Environmental Monitoring and Assessment 2018, 190, 313.

A number of performance characteristics were evaluated including drift, intermediate precision, accuracy of temperature compensation, accuracy of reading (under different measurement conditions), linearity, flow dependence of the reading, repeatability (reading stability), and matrix effects of dissolved salts. The matrix effects on readings in real samples were evaluated by analyzing the dependence of the reading on salt concentration (at saturation concentration of DO). The analyzers were also assessed in DO measurements of a number of natural waters. The uncertainty contributions of the main influencing parameters were estimated under different experimental conditions. It was found that the uncertainties of results for both analyzers are quite similar but the contributions of the uncertainty sources are different.

The results imply that the optical analyzer might not be as robust as is commonly assumed, however, it has better reading stability, lower stirring speed dependence, and typically requires less maintenance. On the other hand, the amperometric analyzer has a faster response and wider linear range.

(Photo by Lauri Jalukse: measurements of dissolved oxygen concentration with amperometric and optical analyzers at Jordan spring, Karksi-Nuia, Estonia)

 

Measurement uncertainty online course (MOOC) 2018 edition successfully finished!

Measurement_Uncertainty_MOOC_Successfully_FinishedOn May 14, 2018 the on-line course (MOOC) Estimation of measurement uncertainty in chemical analysis offered by University of Tartu finished successfully.
Eventually altogether 521 people registered (270 in 2014, 489 in 2015, 757 in 2016, 363 in 2017) from 76 countries (a number of participants joined after the start of the course). 358 participants actually started the course (i.e. tried at least one graded test at least once) and out of them 218 successfully completed the course (141 in 2014, 169 in 2015, 308 in 2016, 148 in 2017). The overall completion rate was 42% (52% in 2014, 34% in 2015, 40% in 2016, 41% in 2017). The completion rate of participants who started the studies was 61% (67% in 2014, 60% in 2015, 67% in 2016, 68% in 2017). The completion rates are nicely consistent over the last years and can be considered very good for a MOOC, especially one that has quite difficult calculation exercises, which need to be done correctly for completing the course.

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 the overall number of posts to them during the course period reached almost 300 (!) (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.

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

We plan to repeat this course again in Spring 2019.

 

Pilleriin, Eliise and Signe at inArt 2018 Conference

On 26-29th March three members of the UT Analytical chemistry group – Eliise, Signe and Pilleriin – attended the conference inArt 2018 (3rd International Conference on Innovation in Art Research and Technology). The conference was held in a small, yet beautiful town of Parma in Italy.

The aim of the conference was to bring together chemists, physicists, geologists, art historians, conservators, archaeologists, etc. to create a wide community and a mutual environment for a fruitful discussion. Four days were filled with wide-ranging presentations, museum visits and interesting discussions with other scientist from the same scientific fields. The work of our cultural heritage group was also introduced with both oral and poster presentations.

On the left picture you can see Eliise standing next to her poster about the comparison of derivatization methods for GC-MS analysis of binding materials in oil paints. The results of this work are going to be published soon.

On the right picture is Pilleriin presenting her work on textile dye analysis. This work has already been submitted.

 

Measurement Uncertainty online course: more than 450 participants from 70 countries!

U_MOOC_Countries_of_Participants_2018On Tuesday, March 27, 2018, the web course Estimation of Measurement Uncertainty in Chemical Analysis was launched the fifth time as a MOOC (Massive Online Open Course)!

Currently, more than 450 participants from 70 countries are registered! As was the case in the previous years, the majority of participants are from analytical laboratories. This once again demonstrates the continuing need for training in measurement uncertainty estimation for practising analytical chemists.

The full course material is accessible from the web page https://sisu.ut.ee/measurement/uncertainty. As is usual, some developments and improvements have been made to the course material. in particular, the description of course organisation was improved; more explanations and examples were added on random and systematic effects within short and long-term; the typical requirements for determining repeatability and within-lab reproducibility have been clearly outlined; more explanations on the main principles of modifying a model in a modelling approach have been given, together with an example. Some changes are still in the pipeline.

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.

 

Measurement Uncertainty MOOC, Mar 27 – May 7, 2018: Registration is open!

Measurement_Uncertainty_MOOC_Course_UTThe third edition of the MOOC (Massive Open Online Course) Estimation of Measurement Uncertainty in Chemical Analysis will be running during Mar 27 – May 7, 2018. Registration is open!

We currently have more than 100 registered participants from more than 30 countries.

The full course material (as well as the registration link) 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 take six graded tests and get higher than 50% score. These tests are available to registered participants via the Moodle e-learning platform. Participants who successfully pass the course will get a certificate from 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!