The admission for EACH intake 2022 is open

We are glad to announce that the admission for Excellence in Analytical Chemistry (EACH) Erasmus Mundus Joint Master Degree programme intake 2022 is open!

EACH is an international two-year joint master degree programme that educates specialists in analytical chemistry well qualified to work in industry (food, pharmaceutical, materials, energy, etc.), chemical analysis laboratories (environment, food, health, etc.), and research (developing new analysis devices or new analysis methods) worldwide. EACH provides knowledge and practical skills in both fundamental and applied aspects of modern analytical chemistry. Practical internship placement in industry or laboratories is an important part of the training.

The programme is suitable both for students who have finished their bachelor’s studies and want to continue in master’s studies, as well as for working analytical chemistry practitioners wishing to spend a couple of years to bring their knowledge and skills to a new level.

The programme features generous scholarships as detailed on the Scholarships and tuition fees page.

The programme is taught by four universities: University of Tartu (UT, coordinator), Estonia; Uppsala University (UU), Sweden; University Claude Bernard Lyon 1 (UCBL), France; and Åbo Akademi University (AAU), Finland. The language of instruction is English, but students will also learn to communicate in one of the languages of the countries involved.

The online application form, admission requirements, deadlines, list of necessary documents, instructions/explanations, as well as contact data for questions are available from the EACH Admission information page.

We wish you all the success in applying!

The 2021 Nobel Chemistry Prize

 

Selleaastased keemianobelistid Benjamin List ja David MacMillan.

We were very pleased to learn today that the the Nobel Prize in Chemistry 2021 was awarded to Benjamin List (Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany) and David W.C. MacMillan (Princeton University, USA) “for the development of asymmetric organocatalysis”!

The List group is world-famous for developing superacidic organocatalysts, enabling a very wide range of challenging transformations. We are happy that there is also a tiny contribution from our group to prof. List’s research: the acidities (expressed as pKa values in acetonitrile of 1,2-dichloroethane) of some of their acid catalysts (1,1,3,3-Tetratriflylpropene and some chiral superacidic imides) have been measured in our lab. Recently we were happy to host people from the List group in our lab and they learned how to carry out pKa measurements in nonaqueous solutions. The collaboration will continue.

Big congratulations to prof. List and to prof. MacMillan!

(Photo: The Nobel Prize committee)

What did people eat in the region of current Estonia in the distant past?

Researchers’ Night festival 2021. Superheroes of science

In English: Last week, on the 20-24 of September, Reasearchers’ Night festival 2021 took place all over Estonia. Our archaeochemist Dr. Ester Oras gave an interesting audio lecture about the eating habits of people living in the region of current Estonia in the distant past. This topic starts with the first findings related to eating habits from the Mesolithic period and arrives at the Middle Ages. During the whole lecture, she illustrates how chemical analyses can be used for the analysis of archaeological objects. Here is the audio lecture in Estonian, but there’s also a blog post in English on a similar topic. 

Eestikeeles: Eelmisel nädalal (20.-24. septembril) toimus üle Eesti 16. Teadlaste Öö festival. Meie arheokeemia töögrupi juht Dr. Ester Oras andis festivali raames huvitava heliloengu, kus ta rääkis mida inimesed sõid kauges minevikus praeguse Eesti aladel. Ester selgitab inimeste toitumisharjumisi Mesoliitikumi ajajärgust (kust pärinevad esimesed toiduga seotud leiud praeguse Eesti aladel) Keskajani välja. Kogu loengu vältel kirjeldab Ester ka seda, kuidas keemilised analüüsid aitavad mõista arheoloogilisi leide. Mainitud eestikeelse heliloengu leiab siit, kuid samal teemal on olemas ka ingliskeelne blogipostitus.

Derivatization-targeted analysis of amino compounds in plant extracts by LC-MS/MS

In the recently published paper including the members of our Analytical Chemistry Chair, a method was developed to detect amino compounds with diethyl ethoxymethylenemalonate (DEEMM) derivatization in neutral loss scan mode by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Amino compounds react with DEEMM, and the derivatives lose a neutral ethanol molecule [M+H-46]+ from the parent ion upon collision-induced dissociation (CID) fragmentation. Therefore, it is possible to employ neutral loss scan (NLS) mode of the triple quadrupole mass analyzer.

The first part of the work was dedicated to the development of the method, such as testing different solvents and quenching reagents in order to obtain a cleaner chromatographic profile. Hydroxylamine was chosen as the quenching reagent, considering the retention time of its DEEMM-derivative and its solubility in the solvent employed (0.1 M HCl in 30% methanol).

Finally, the developed method was applied to an extract from the plant species Carduus nutans subsp. macrocephalus (Desf.) Nyman, in which 18 amino acids and 3 biogenic amines were identified for the first time in this plant species. The method can be applied to different matrices for the detection of known and unknown amino compounds.

Here you can find the 50-day free access to the article.

Design of Novel Uncharged Organic Superbases: Merging Basicity and Functionality

Emerging organosuperbase families
Examples of emerging organosuperbase families

In a recent account Design of Novel Uncharged Organic Superbases: Merging Basicity and Functionality. Acc. Chem. Res. 2021, 54, 3108-3123 four groups doing research at the forefront of superbase chemistry – IOCB (Czech Republic), Rudjer Boskovic Institute (Croatia), Philipps-Universität Marburg (Germany) and our group at University of Tartu – have joined forces in charting the direction for further developments of the whole organosuperbases area. What synthetic chemists need, are “non-ionic, metal-free superbases as chemically stable neutral organic compounds of moderate molecular weight, with intrinsically high thermodynamic basicity, adaptable kinetic basicity, and weak or tunable nucleophilicity at their basicity centres”. Such superbases would be are useful, being able to catalyze a number of reactions that are impossible otherwise.

The account demonstrates that just trying to achieve ever higher basicity is not the main challenge. Very high basicities have been demonstrated, both computationally and experimentally. Instead, the combination of high basicity with moderate molecular weight, ease of synthesis and stability is the key issue.

The account starts with the state of the art of neutral organic superbase research, theirs synthesis and basicity measurements, as well as computations and thereafter presents several examples of emerging organosuperbase families (see the Figure on the left) and discusses their synthesis, basicity and demonstrated, as well as potential applications.

Dr. Merit Oss, PhD thesis on the ionization efficiency in ESI

On the 24th of August, 2021, Merit Oss successfully defended her PhD thesis titled “Ionization efficiency in electrospray ionization source and its relations to compounds’ physico-chemical properties” 

The thesis by Merit revolves around ionization efficiency in electrospray ionization (ESI) MS. The main aim was to gain a better understanding of the relations between different molecular properties of compounds and the signal intensities of their ions in ESI-MS. During this study, a large number of ionization efficiency values were obtained. Eleven molecular parameters were taken into account for estimating their importance for evaluating the compound’s ionization efficiency in ESI. It was concluded that in the studied solvent system, a compound’s ionization in the ESI source is determined by its basicity, molecular size, and hydrophobicity/lipophilicity. The results showed that the obtained models for estimating compounds’ ionization efficiency can be used for approximate prediction. 

Congratulations, Merit! We wish you all the best for your future. 

 

Dr. Eliise Tammekivi – PhD thesis on the quantitative analysis of oils

Last Friday, on August 27, 2021, Eliise Tammekivi successfully defended her PhD thesis titled Derivatization and quantitative gas-chromatographic analysis of oils.

In the PhD thesis by Eliise, four derivatization procedures that are widely used for the analysis of oils in cultural heritage or archaeology were compared based on quantitative gas-chromatographic (GC) analysis. It was seen that the TMTFTH derivatization was the most suitable one for the GC analysis of fresh oils. An in-depth uncertainty estimation was performed for one of the derivatization procedures using the ISO GUM approach and the Monte Carlo method. Another one of the improved procedures was applied for the analysis of self-made artificially aged paint samples that had varying pigment to linseed oil ratio to see if the pigment concentration had an effect on the drying of the paint samples.

Additionally, small samples from two paint case study samples relevant to the history of Estonia – crucifix from Karja church and cupboard from Ruhnu island – were analyzed to obtain information about the materials in the paint samples. Finally, the improved quantitative method was used to quantify fatty acids present in yeast cells. 

Congratulations to you, Eliise!  

 

New publication: Classification of archaeological adhesives

Our group recently published a new article: Classification of archaeological adhesives from Eastern Europe and Urals by ATR-FT-IR spectroscopy and chemometric analysis. Archaeometry, 2021, 1–18. 

In this study, 100 adhesive samples, collected from hafting tools and ceramic containers as well as some adhesive lumps were analyzed using ATR-FT-IR in combination with PCA-based DA classification. The aim of this study was to discover the capabilities of ATR-FT-IR-DA classification as a potential screening method for the identification and grouping of different archaeological adhesive samples, and subsequently reduce the use of laborious GC-MS analysis.

100 archaeological adhesives were classified into 3 groups: birch bark tar without major additives (72), birch bark tar with additives (13) and minor/non birch bark tar samples (15). Birch bark tar containing adhesives were separated from minor/non birch bark tar samples. Samples identified as birch bark tar without major additives were further classified possibly by their location, age or cultural specific manufacturing practices. The classification results were confirmed by GC-MS analysis of 9 archaeological samples selected from three compositional groups.

The study proves that ATR-FT-IR-DA classification is a non-destructive, rapid and reliable pre-scanning method for analyzing archaeological adhesives, especially suitable for small samples. Based on the results of ATR-FT-IR spectroscopic analysis, DA classification can help further distinguish samples with different backgrounds such as sample age, initial production, environmental conditions and site-specific preservation. GC-MS analysis could be used as a supplementary/confirmatory method to investigate samples with complex components and provide archaeological DA references for future research.

The full text can be found here.

Dr. Astrid Darnell – PhD thesis on the study of anion receptors

On the 20th of May, 2021, Astrid Darnell defended her PhD thesis titled “Computational design of anion receptors and evaluation of host-guest binding“. 

In the thesis by Astrid, the main aim was to study possible new receptor molecule candidates with computational methods. This could improve the design of receptors used for the detection of various important anions (including glyphosate dianion and small monocarboxylate anions). 

The suitability of the COSMO-RS method was tested for studying receptor molecule and anion binding. It was also demonstrated that COSMO-RS was shown to predict correctly the most stable conformers of the majority of the studied molecules. 

The effects of receptor and complex geometries and the spatial matching between host and guest species on the binding affinity of large, structurally complex receptors was investigated towards a selection of analytically interesting carboxylate anions. A number of these receptor structures are now being investigated for practical applications as real carboxylate anion sensors in the form of SC-ISEs.

The final part of the study investigated the applicability of isothermal titration calorimetry (ITC) experiments for the determination of the thermodynamic parameters (e.g. reaction entalphy ΔH) of host-guest binding reactions. Low-volume ITC experiments were found to be applicable for the study of low-affinity host-guest binding reactions and the combined standard uncertainty for reaction entalphy determination for these experiments is in the range of 1-2kJ/mol.

Congratulations to you, Astrid!

Measurement uncertainty online course 8th run has successfully finished!

On May 13, 2021, the online course (MOOC) Estimation of measurement uncertainty in chemical analysis offered by the University of Tartu finished successfully.

Eventually, altogether 950 people registered from 97 countries. 501 participants actually started the course (i.e. tried at least one graded test at least once). The overall completion rate was 33%. This, as well as the participating rate, was the lowest (53%) we have seen. However, the completion rate of the participants who started the studies was 63% with 314 successfully finished participants. This result can be considered very good for a MOOC, especially for one that has quite difficult calculation exercises, which need to be done correctly for completing the course. All statistics during the 8 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 close to 400 (!) (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 2022.