Tartu City Government acknowledged the organizers of Eurachem 2019!

On the 18th of February, the City Government of Tartu acknowledged the organizers of 14 international conferences that took place last year in Tartu, Estonia.

Mayor Urmas Klaas said that the high-level international conferences make Tartu visible in the field of conference tourism. In the future, the number of these well-organized conferences could be even higher, when Tartu becomes the European Capital of Culture in 2024 and additional flights from Tartu start to operate.

One of the acknowledged conferences was the Eurachem Workshop and General Assembly 2019, which was organized by the Estonian Center of Analytical Chemistry (ECAC). 

Congratulations to the main organizer Riin and her team – Ivo, Anneli, Asko, Koit, Hanno, Jaanus, Pilleriin, Eliise and Siiri from our Analytical Chemistry Group for the well-deserved recognition! 

The secrets of two mummies have been unravelled

PLOS ONE has recently published a multidisciplinary paper on two Egyptian child mummies lead and participated by the members of our group. The team of 19 experts unravelled the secrets of two Graeco-Roman child mummies by applying most recent analytical techniques from archaeology, forensic sciences, analytical chemistry, medicine, entomology, and genetics. This is one of the most extensive multidisciplinary study of ancient mummies and the paper is free to download here.

Celebrating Christmas with our Analytical Chemistry family

Last week, the members of our Analytical Chemistry group celebrated Christmas together. 

After the traditional and tasty Christmas dinner, the not so traditional games took place. Everyone was dived into five teams. All of the teams had the same five tasks – they had to put their main senses to the test. But of course, the tasks required some additional knowledge of chemistry. 

The tasks were the following: identify common laboratory objects in a self-made and a not see-through “glove box” (touch); recognize the sounds of various laboratory machines, including the coffee maker (hearing); notice molecules and atoms in a drawing (sight); determine the concentrations of sugar solutions by tasting sugar solutions with known concentrations (taste); identify various alcohols and fragrant compounds by their aroma. The games of senses ended with a fun quiz.

                                   Touch

HearingSightTasteSmell

Wishing you happy holidays and a wonderful new year from our Analytical Chemistry group!

Jaanus Liigand was awarded the 1st prize in Estonian National Contest for University Students for his doctoral thesis

Jaanus Liigand was awarded the 1st prize in category of natural sciences and technology in the Estonian National Contest for University Students supported by Estonian Research Council for his doctoral thesis.

He defended his PhD thesis on “Standard substance-free quantification for LC/ESI/MS analysis based on the predicted ionization efficiencies”. During his PhD studies, Jaanus has worked hard on understanding the mechanism of electrospray ionization in LC/ESI/MS; primarily understanding how the structure of the compound and the eluent used in the analysis influence the ionization efficiency. Jaanus has verified, based on the largest set of ionization efficiencies measured so far (roughly 400 compounds), that the more hydrophobic compounds and more basic compounds tend to have a higher response in ESI positive mode. From the mobile phase point of view, both organic solvent content, pH of the buffer, and buffer composition, influence the ionization efficiency in ESI/MS. In general, higher organic solvent content and lower pH result in higher ionization efficiency and, therefore, a higher response in positive mode ESI/MS.

Dr. Piia Liigand and Dr. Jaanus Liigand

Also, he investigated how well are the ionization efficiency values measured on one instrument transferable to other instruments and found that with the aid of 5-6 common compounds the ionization efficiency values can be transferred from one instrument to another. Combining these promising results and machine learning approaches Jaanus has been able to develop a truly universal approach for applying ionization efficiency predictions for quantification in suspect and non-targeted LC/ESI/HRMS analysis.

He is continuing his research at University of Alberta in Canada in Prof. David Wishart research group to further improve mass spectrometric analysis with machine learning.

Congratulations to you, Jaanus, for the well-deserved acknowledgment!

New non-invasive approach to analyze textile fibers

Another new method development in our group has been assembled into a publication. Article by Pilleriin Peets (on the picture), Karl Kaupmees,  Signe Vahur, and Ivo Leito in the journal of Heritage Science introduces non-invasive approach to identify all kinds of different textile fibers using reflectance-FT-IR spectroscopy and chemometry. In this work 61 single-component textile pieces were analyzed, 4000 spectra were recorded and all in all 16 different textile fiber types were characterized. As reflectance-FT-IR spectroscopy is not widely used to analyze samples with an uneven surface, in our best knowledge, this article provides the largest collection of r-FT-IR spectra from textile fibers that is recorded and published. All the r-FT-IR spectra from different fiber classes are now available for other scientists, conservators, museum workers and industries to use!

PCA classification graph of different textile fiber classes. Peets, P., Kaupmees, K., Vahur, S., Leito, I. Reflectance FT-IR spectroscopy as a viable option for textile fiber identification. Herit Sci  7, 93 (2019)

EU_FT-ICR MS short courses continue to be extremely useful

Another EU_FT-ICR-MS short course took place on the 10-12 October in Moscow, Russia, this time the topic was the basics of FT-ICR: dynamic harmonization and computer simulation. Two of our group members – Pilleriin Peets and Eliise Tammekivi – also took part in this interesting course. 

In the recent EU_FT-ICR-MS short course, scientists and students from the Skolkovo Institute of Science and Technology (Skoltech) shared their work and knowledge in the field of FT-ICR. Prof. Jevgeny Nikolaev was one of the main organizers of the event and also gave lectures, where he explained the essence of a dynamically harmonized cell and the processes taking place in different ICR cells. In the seminars, the computer simulations that are used in the lab of Prof. Nikolaev for modifying ion motion were introduced and demonstrated.

  • Nikolaev
    Prof. J. Nikolaev explaining the processes of ICR
  • Aleksander
    Dr. A. Zherebker demonstrating their FT-ICR

Besides the lectures and seminars, the participants were shown around the Mass Spectrometry Lab and the facilities of Skoltech. Skoltech is an innovative and international university with students and lecturers from all over the world. The university was established in 2011 in collaboration with MIT and by now they have a nearly finished campus where students and researchers can cooperate with start-ups and industrial companies. To give some idea about their wide possibilities, weʼll give you an example – besides numerous “common” plastic 3D printers, they have several metal, ceramic and composite 3D printers that students apply in their projects and scientists in their research.

 

New publication – retention studies in C18 column using novel fluorinated eluent additives

It is essential to understand the interaction between the analyte, mobile phase and the column chemistry for the best possible separation of molecules. Of all three, the mobile phase in HPLC is the easiest to modify and thus, usually contains different eluent additives or buffers. While using mass spectrometry undoubtedly increases the variety of analytes possible to detect, it also introduces limiting factors such as the requirement of the volatility of the eluent. Most common additives in LC-MS systems are formic and acetic acid, their ammonium salts as well as ammonium bicarbonate. In our recent paper, we have proposed novel – fluorinated, eluent additives (hexafluoroisopropanol, hexafluoro-tert-butyl alcohol, trifluoroethanol as well as nonafluoro-tert-butyl alcohol and perfluoropinacol).  Their influence was shown on rather simple exemplary molecules, which are widely spread over different logP values, containing protonated and deprotonated acids and bases. All novel fluorinated eluent additives demonstrated a strong influence on basic polar analytes in basic medium – they drastically increased retention. A decrease in retention was observed for acidic analytes when these novel eluent additives were used.

Moreover, current research displays a comprehensive overview of retention mechanisms for nonafluoro-tert-butyl alcohol and is the first time ever when perfluoropinacol has been introduced as eluent additive for reversed phase chromatography. Additionally, the influence on MS signal was studied when fluoroalcohols were used as eluent additives. This is also the first time when the absolute pH (pHabs) scale was used for expressing the mobile phase pH.

Current fundamental research forms a basis for a better understanding of the influence of fluoroalcohols as eluent additives and will help in the assay development in a wide range of applications.

This work is part of a larger endeavor – to promote a wider usage the unified pH scale (pHabs) by the research and technology communities, which is currently in progress via the UnipHied.

The UnipHied project 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.

 

 

New publication – Instrumental techniques in the analysis of natural red textile dyes

A wide variety of different dyes, complex composition of natural dye sources and low concentrations in samples make the identification of textile dyes challenging. In our cultural heritage group, work has been done for years to overcome some of these problems. Using seven different red dye sources and five instrumental approaches, a method for the analysis of textile dyes has now been developed in our lab to study different archaeological findings, museum artifacts, and other textile pieces. More about the results can be found in the article published in the Journal of Cultural Heritage by P. Peets, S. Vahur, A. Kruve, T. Haljasorg, K. Herodes, T. Pagano and I. Leito.

The usefulness of this developed method has been proved by analyzing several case-study samples from Estonian National Museum, KANUT, and private collections. Thanks to the multiple instrument combination and especially the usage of high-resolution mass-spectrometry, it was also possible to identify synthetic organic dyes without the use of any standard substances.

17th Nordic Mass Spectrometry Conference in Espoo

In the last week of August, the 17th Nordic Mass Spectrometry conference was held in Espoo, Finland. With around 150 participants from Nordic countries, the conference covered various different topics within the field of mass spectrometry.

Anneli making her presentation at the 17th NordicMS

From our group, Anneli Kruve presented some of the most recent results in the field of quantitative suspect screening for pesticides and mycotoxins. Riin Rebane presented a poster about analyzing metanephrine (MN) and normetanephrine (NMN) and also about unusual matrix interferences related to the analysis (results have been published here). Artur Gornischeff presented some very exciting results on the ionization studies of derivatized amino acids which have also been published here.

  • Riin with her poster
  • Artur with his poster

NordicMS is a mass spectrometry conference taking place every three years and hosted in turns by nordic countries. This time it was Finland’s turn. The three-day conference had roughly 150 attendees; as expected, primarily from Finland and other Nordic countries. The conference covered all major areas of application of mass spectrometry: food characterization, metabolomics, drug discovery, proteomics, doping discovery and forensics. Topics covered analysis from the sea bottom (Hanna Niemikoski’s presentation about the identification of novel chemical warfare agents) up to the sky (Kari Hartonen’s presentation about sampling from air with drones).

The conference showed that even in the small circle of Nordic countries the research in the field of mass spectrometry is diverse and every mass spectrometry enthusiast will find his or her spot in the field.

Successful Master’s defense about ValChrom software

Thesis: “Software Tool for Validation of Chromatographic Analytical Method” by Kodjovi Hippolyte-Fayol Toulassi

Kodjovi Hippolyte-Fayol Toulassi defending his thesis

The aim of the work was the development of the back-end for ValChrom software. It was jointly supervised by professor Marlon Dumas (Institute of Computer Science) and Koit Herodes and Asko Laaniste (Institute of Chemistry). Kodjovi successfully presented both the chemistry and computer science aspects of the thesis, gaining praise from the supervisors and the opponent.

The software

ValChrom is a software tool developed with the aim of easing the burden of analytical chemists at chromatographic method validation. In ValChrom the user chooses the validation approach (Kodjovi implemented 3 guidelines: ICH, EMA bioanalysis, and Eurachem) and software recommends a respective experimental plan.

After importing experimental results, ValChrom calculates results and generates a report. Feedback and suggestions are welcome at valchrom@ut.ee.