On 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.
The 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!
Charged droplets occur everywhere in the world. They are created by the oceans (known as sea spray aerosols), near waterfalls and in thunderstorm clouds. Such droplets are expected to play significant role in environmental processes. Similar droplets are also created in electrospray ionization (ESI) source.
Mari Ojakivi joined Mass Spectrometry lab three years ago to conduct her bachelor thesis with us. Mari started studying how different acids, salts, and bases influence the ionization of some amines in charged water droplets. Soon, some extremely interesting results were revealed that allowed to make much wider conclusions about charged droplets.
It became possible to pinpoint, that protonation of the amines is strongly dependent on the type of additives present in the droplets and is virtually independent of the pH of the solution used for “preparing” the droplets. In “normal” solutions the protonation is determined solely by the pH of the solution. This led us to conclude that some of the additives change something about the droplets that other additives do not affect. It turned out, that the factor determining the protonation is the cation present near the surface of the charged droplets. Cations, such as hydronium ion, which are strong acids protonate the compounds, while weak acids, such as ammonium cation, do not. If both types of cations are present in the solution, the protonation is determined by the ion that has higher affinity for the droplets surface. The support for this model was found from the molecular dynamics simulations carried out in Prof. Konermann’s group.
Why is the protonation in charged droplets at all important? Protonation is one of the fundamental properties of compounds; it may catalyze reactions, break up or induce complexation, change conformation of the macromolecules, etc. Therefore, it can be assumed, that the reactions and processes taking place in charged droplets also depend on the protonation.
The results were published in ChemistrySelect .
Agnes Heering successfully defended her PhD thesis on experimental realization of the unified pH scale
On December 6, 2017 Agnes Heering successfully defended her PhD thesis titled Experimental realization and applications of the unified acidity scale.
Her work literally redefines the way the pH of non-aqueous and mixed aqueous solution is understood and measured. The main focus of the experiments was on validating the measurement approach and measuring the unified pH values, i.e. pHabs values, of HPLC mobile phases (eluents). Her work introduces a conceptually new approach of measuring pH of mixed-solvent liquid chromatography (LC) mobile phases and has been published in the Analytical Chemistry journal: Unified pH Values of Liquid Chromatography Mobile Phases. Anal. Chem. 2015, 87, 2623–2630.
Mobile phase pH is very important in LC, but its correct measurement is not straightforward and all commonly used approaches have deficiencies. The new and fundamentally correct approach developed by Agnes enables direct comparison of acidities of solutions made in different solvents, based on chemical potential of the proton in the solutions.
The work by Agnes represents the first experimental realization of the pHabs concept using differential potentiometric measurement for comparison of the chemical potentials of the proton in different solutions (connected by a salt bridge), together with earlier published reference points for obtaining the pHabs values (referenced to the gas phase) or pHabsH2O values (referenced to the aqueous solution). The liquid junction potentials were estimated in the framework of Izutsu’s three-component method.
She determined the pHabs values for a number of common LC and LC-MS mobile phases and formed a self-consistent pHabs scale. This scale enables for the first time direct comparison of acidities of any LC mobile phases: with different organic additives, different buffer components etc. Agnes has developed a possible experimental protocol of putting this new approach into chromatographic practice and has tested its applicability. She has demonstrated that the ionization behavior of bases (cationic acids) in the mobile phases can be better predicted by using the pHabsH2O values and aqueous pKa values than by using the alternative means of expressing mobile phase acidity. Description of the ionization behavior of acids on the basis of pHabsH2O values is possible if the change of their pKa values with solvent composition change is taken into account.
The defence was successful in every respect. Agnes presented very well, answered questions confidently and convincingly demonstrated to everyone that she is really on top of this whole matter.
(Photo: Agnes Heering and prof. Peeter Burk, the chairman of the defence committee, during defence)
We are glad to announce that the 2018 admission is officially open to the 4th intake of the Excellence in Analytical Chemistry (EACH) Erasmus Mundus Joint Master Degree programme!
This international two-year joint master degree programme 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 couple of years to bring their knowledge and skills to a new level.
The programme features generous scholarships as detailed in 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!