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”.
Dr. Anneli Kruve defended her PhD thesis – “Matrix effects in liquid-chromatography electrospray mass-spectrometry” in University of Tartu in 2011 under the supervision of prof. Ivo Leito and dr. Koit Herodes. Right after she got her first personal funding and established the electrospray ionization efficiency studies group. In addition to understanding the ionization mechanism for small molecules in electrospray, she is interested in using charged nanodroplets generated by electrospray as an organic synthesis medium. In 2016 Dr. Anneli Kruve moved to Haifa, Israel to do her first post-doc at the Technion’s Schulich Faculty of Chemistry in Prof. Israel Schechter’s group. Right now, she is a Humboldt Fellow in the Institute of Chemistry and Biochemistry at Freie Universität Berlin in Germany in Prof. Christoph Schalley’s group.
In addition to excellent science, she is spreading the knowledge as she has designed and is actively lecturing different courses (instrumental analysis lab, statistics in analytical chemistry to name some) in analytical chemistry and statistics in analytical chemistry. She has also supervised several PhD and numerous MSc and BSc students.
Early inspiration
“I got started in organic synthesis but quickly joined a biomedical lab that needed students to operate a HPLC. From there, moving to LC/MS was a natural step. The ability to incorporate various skills from IT to synthesis with mass spectrometry-based research has kept me motivated to stay on this path.”
Research
“My field is structural and quantitative characterization of compounds with LC/ESI/IMS/MS. A key focus of mine is developing the possibility of giving a quantitative context to non-target LC/HRMS data without the need for standard substances.”
Greatest achievement
“I have already seen many students moving from our lab to the workforce and receiving positive feedback from their employers – that definitely makes a former supervisor happy!”
Prediction
“Mass spectrometry has already changed almost everything; its impact will increase further, as we make non-target screening more efficient with effective algorithms, and make it quantitative. I also have a dream technique: I sometimes wonder what the world would look like with MS-(gas phase)NMR . . .” (The Analytical Scientist)
We are very happy and proud that Dr. Anneli Kruve received this well-deservedly recognition of being nominated to the Top 40 Under 40 Power List by the Analytical Scientist!
From the 9th to the 13th of September MSACL EU 2018 Annual Congress took place in the cosy city of Salzburg, Austria. This conference was designed to mass spectrometry audience mainly focusing on clinical applications. I had the opportunity to participate in this inspiring conference. Moreover, I had the possibility to give a talk. I introduced our studies on standard substance free quantitation in LC/ESI/MS analysis.
Lightning talks to encourage young scientists
Prof. Jerzy Adamski kicked off the conference with the plenary lecture on the topic “Metabolomics Messages on Human Health and Diseases”. As one of the main goals of this conference is to inspire and encourage the young scientists the next session was lightning talks. Poster presenters had 90 seconds and one slide to present their research and cultivate interest in their topic. Additional possibility to get to know mature scientist was the program “meet the experts”. There were short meetings as well as booth and poster tours with experts. I had the possibility to analyze some posters together with Dr. Oleg Mayboroda from Leiden University Medical Centre. It was nice to see how the experts look at the posters and how and which questions they ask. Dr. Mayboroda gave a checklist of how to assess the goodness of the PCA plot presented on posters.
Scientific highlights of the conference
There were 5 parallel sessions every day. For me, the three highlights were as follows. First of all, Dr. Mario Thevis gave a talk about mass spectrometry in sports drug testing. Also, Prof. David Millington gave an interesting talk about the role of tandem mass spectrometry in newborn screening. It was encouraging to see how the methods developed by his team save around 2500 newborns on yearly basis. Furthermore, Dr. Lyudmilla Yanshole gave a talk about using postmortem tissues for biomarker identification. It is an interesting study as for lots of diseases it is very difficult to get tissue of healthy species.
Standard substance free quantification LC/ESI/MS
I had the possibility to present for the first time a talk at an international conference. For that, I am most grateful for the MSACL organization and the scientific committee. I introduced the recent results on the feasibility of standard substance free (semi)quantitation in LC/ESI/MS using ionization efficiency prediction models. We have measured more than 2000 ionization efficiency values. We have incorporated 21 solvent compositions. The models are developed based on descriptors calculated from the 2D structure of compounds and the predictions perform well even in complex matrices, namely, bodily fluids. Our average misprediction of ionization efficiencies is less than 3.5 times mismatch. I thank the audience for fruitful discussions on the topic.
Salzburg is a lovely city with stunning views of the Alps. Furthermore, the organizer made our stay at the conference very enjoyable with the nice coffee breaks and warm buffet for lunch and dinner which were offered every day.
From 26 to 31 of August Florence hosted a vast majority of mass spectrometry scientist in the course of 22nd International Mass Spectrometry Conference. Among these were also our group members researchers Anneli Kruve and Riin Rebane, PhD students Piia Liigand and Jaanus Liigand, MSc student Mari Ojakivi and a visiting PhD student Tingting Wang from the Technical University of Denmark. We had a chance to present altogether 5 posters at the conference. Our posters can be found here. As is the case for IMSC, the topics ranged as wide as it can be for mass spec and always there was something to see and hear. We were happy to see that there was a lot of interest in our work. Congratulations to Anneli, whose poster received Chemistry – A European journal poster award! The conference was accompanied by delicious Italian food and nice warm weather. We enjoyed every second of this highly intensive week and are looking forward to IMSC 2020 in Rio.
Anneli Kruve: It is no secret that I am very keen on non-target screening methods, so I really enjoyed all the talks and posters regarding non-target screening and compound identification. My favorite talk was actually also in the field of compound identification given by Prof. Rober Mistrik in the Thermo lunch seminar. He very nicely explained the Precursor Ion Fingerprinting strategy and explained some of the new tips and tricks which are now combined in the Mass Frontier 8.0. It also very strongly resonated with the perspective I recently wrote about semi-quantitative non-target screening. I also have to mention the plenary lecture by Prof. Marco Leona from Metropolitan Museum of Art, who did not focus specifically on mass spec but gave us a really nice overview of scientific research of art. I constantly kept thinking how beautiful it is to have a background in chemistry: one can, virtually, combine all interest and make a great new whole. Prof. Leona, for example, was combining beautiful artworks, history of humankind, the biology of colorful bugs and plants, and on top of that mass spectrometry. And I definitely also felt honored to receive my best poster prize awarded by Chemistry – A European Journal!
Riin Rebane: It was my first experience of Florence as well as IMSC and when the first one greeted with wonderful food, the second one gave food for thought. It was a thorough overview of the latest advances in mass spectrometry and an insight into different works of scientists from academia as well as industry, therefore, it was certainly a challenge to grasp it all. But despite that, it was also nice to see that sessions towards practical applications of mass spectrometry in for example food or environmental analysis, were so popular that arriving late meant that all seats were already taken by other enthusiasts.
Mari Ojakivi: IMSC 2018 was the first scientific conference that I attended and as a master’s student it was an eye-opening experience. It was very nice to see so many scientists introducing their brilliant work with a mass spec. Seeing all the different applications in forensics, food and environmental science, as well as fundamental research in all the -omics fields made me understand how powerful tool mass spectrometry is. What is more, presenting my own work and seeing other scientists being so interested in it, verified that I am doing good and important science.
Piia Liigand: I thoroughly enjoyed the IMSC 2018 in Florence. It was a nice opportunity to meet and talk to scientists from all over the world. I was also very positively surprised to see so much interest in my poster and I truly enjoyed the discussions I had while presenting my poster. Thanks to these discussions I now have even more understanding of the importance of the science we do and what to do next. I also enjoyed meeting friends from past conferences and catching up on their research in more detail. Of course, the food, wine and general ambiance of Florence was an excellent environment to do all that.
Jaanus Liigand: I enjoyed the IMSC 2018 in Florence as it offered a very wide set of different interesting topics of mass spectrometry field. The inspiring presentations, fruitful discussions, interdisciplinary ideas, and excellent community made it a very enjoyable conference. My favorite session was environmental MS where Prof. Susan Richardson gave in her keynote a very nice overview of the recent developments in this field followed by interesting presentations. Additionally, I enjoyed meeting friends from previous conferences and discussing their and our research. Of course, the historical city – Florence – with the food and wine scenery made the week even more enjoyable.
Tingting Wang: It was a really memorable experience to participate IMSC in Florence, and I enjoyed the atmosphere and all the academic events there. It’s so impressive how wide are the application fields that mass spectrometry can do in the world by looking through a thousand posters. It’s hard to say which presentation or poster was my favorite, but I do pay more attention to the non-target screening strategy applied in food control, environmental, metabolomics, and proteomics study, especially the workshop on the second day about non-target analysis. It was interesting and very informative because unknown screening by high-resolution mass spectrometry is the topic of my PhD project, how to combine target and non-target screening, how to develop a more precise identification and quantification strategy for the non-target even unknowns, and how to prioritize unknowns are the problems I am always facing. It is nice that I could see these similar studies with various workflows from other researchers, and have the chance to listen to their presentations and even talk with those people to get inspiration for my research.
Anneli, Riin, Mari, Jaanus and Piia presenting their posters.
This week two PhD students of our group, Rūta Veigure and Max Hecht had a chance to present their research in the 7th European Association for Chemical and Molecular Sciences (EuCheMS) Congress in Liverpool, organized by the European chemistry society. The conference offered a 5 day packed programme and celebrated the organization of different chemists in societies all over the world. For example, the Estonian chemical society is turning 100 years this year.
Rūta Veigure presented a poster on “Widening the range of eluent additives for LC-MS analysis to improve the retention of drug-like molecules”, while Max Hecht delivered a talk on the “The Evolution of Sponge spray for direct Sampling and Analysis by MS”.
Liverpool itself offered a variety of sights and enjoyable experiences, and as being the home-town of Beatles, there was even a chance to enjoy the tribute band “The Bootleg Beatles” during one of the Congress’ evenings.
The logIE approach is already applicable in nice clean matrices such as neat solvents. We wanted to see if our approach also works with more difficult matrices, such as bodily fluids and tissues. The results were recently published in Analytica Chimica Acta.
In this study, we took a representative set of 10 compounds, including drugs, e.g., naproxen and lincomycin. As matrices, we used blood, plasma, urine, cerebrospinal fluid, brain and liver tissue homogenates and neat solvent to compare with. We carried out a simple and robust sample pretreatment of protein precipitation. We measured the IEs in a worst-case scenario in flow injection mode without any chromatographic separation.
As with different instrumental setups and solvents, the IEs vary between biological matrices, but the order of the compounds remains roughly the same. These variations between different matrices and variations between a certain biological matrix and neat solvent demonstrate that matrix affects ionization efficiencies and also the prediction models of ionization efficiencies. This, in turn, shows that matrix affects the importance of properties of compounds in the prediction model.
Even though the effects are big and matrix effect is strong we were happy to see that the correlations between IEs measured in the neat solvent and IEs measured in a biological matrix are in good correlation (R2 from 0.7 to 0.9). These good correlations were a promising start to predict IEs in biological matrices similarly to previous predictions in the neat solvent. The most accurate model was obtained for the solvent with a mismatch of 2 times which was also expected since it is the cleanest matrix. But also for liver and brain tissues the mismatch of the model is only 3-fold.
The correlation between predicted and calculated IEs is good with the average mismatch over all biological matrices of 8 times. This means that the accuracy of standard substance free quantitation has been improved by more than an order of magnitude for the set of compounds used in this study.
More details can be found in the paper published in Analytica Chimica Acta. Piia Liigand also gave a talk on the topic in ASMS which can be found here. More papers by our group on the topic of ionization efficiencies can be found here.
Results below the limit of quantification (BLQ) are generally not reported or reported without explicit numbers, leaving pharmacokinetic (PK) and pharmacodynamic (PD) studies wishing for more information to improve their model parameters. But the laboratory cannot release actual values BLQ since the quality of that data has never been assessed.
By directing this article towards the pharmacometrician, the analytical scientist and the regulatory personnel, we hope to encourage an inter-disciplinary discussion to improve the situation by finding ways to use BLQ data in PK/PD studies, in order to enhance the quality of the obtained pharmacokinetic models. Several ways were proposed for moving forward, in particular improving/modifying method validation guidelines for enabling to use BLQ data and leaving the decision regarding whether and how to incorporate the BLQ data into a PK/PD model to the data analyst and not the analytical chemist.
On 3rd-7th June three members of our group focusing on ionization efficiency studies Dr. Anneli Kruve-Viil, PhD students Piia Liigand and Jaanus Liigand, participated in the 66th Annual Conference of American Society for Mass Spectrometry (ASMS) in San Diego, CA. The conference was a huge success. There were altogether about 7500 scientists participating, ca 200 oral presentations and 3300 of posters. We had two oral presentations and one poster presentation.
The conference was kicked off by a presentation by Lisa Shipley from Merck who gave a very informative talk about smart trials and moving to patient-centric clinical trials – most probably the future of clinical trials. It was very inspiring to see how a field that is considered to be relatively conservative is picking up the most modern technical solutions such as clever packages and home-based sample collection.
The first full day of the conference started with a presentation by our PhD student Piia, who gave a talk about achieving more accurate semi-quantitative analysis by predicting electrospray ionization efficiencies. She first gave an overview of the research carried out so far and then, introduced her latest results. She showed that with the help of using ionization efficiencies, concentration estimation in various biological matrices was improved by more than an order of magnitude.
Jaanus Liigand presenting his poster
Jaanus presented a poster on semiquantitative LC/ESI/MS via ionization efficiency prediction. He presented the simple and user-friendly approach of predicting ionization efficiencies using only 2D structures. We are now able to predict ionization efficiencies in both ESI positive and negative mode and in different solvent compositions without time-consuming DFT-COSMO calculations. Additionally, we have shown that using ionization efficiency predictions the validation with LC gradient elution resulted in 2.7-fold mispredicted concentrations compared to 44-fold mispredictions using directly peak areas. We were happy to see that numerous groups were interested in our studies and fruitful discussions about the results did not stop until the end of the poster session.
Dr. Anneli Kruve-Viil giving her talk
Dr. Anneli Kruve-Viil presented some of the latest results obtained in FU Berlin. She talked about using mass spectrometry and ion mobility spectrometry for investigating interlocked nature of catenanes and knots. These results will soon be shared with everyone.
In conclusion, this year’s ASMS was very successful for our group. We saw a lot of interest in our work, met our collaborators and got some new friends and possible future collaborators. We are already looking forward to the next ASMS in Atlanta. We are also grateful for our financial supporters, who made this conference possible to us: instrumentation provided by Estonian Center of Analytical Chemistry (www.akki.ee), Ministry of Education and Research of Estonia by smart specialization doctoral stipend, Graduate School of Functional Materials and Technologies, and Alexander von Humboldt Foundation.
More information about the group focusing on ionization efficiency studies can be found on the webpage kruvelab.com
Sum of pesticide traces in samples from 2016-2017. Source: Estonian Environmental Research Centre
Our joint research fellow with Estonian Environmental Research Centre Dr. Riin Rebane and joint PhD candidate Siiri Saaver participated in the study “Analysis of pesticide traces and dynamics in surface and groundwater” . In this study, 137 surface and groundwater samples from all over Estonia were analysed with a targeted screening of 135 pesticides. From 137 analysed samples 49 pesticide traces were detected in more than half of the samples. In 34 samples 9 pesticides and their metabolites exceeded the allowed concentration level of 0.1 μg/L. In 9 samples pesticides and their transformation products exceeded 0.5 μg/L. Interestingly, the main compound found (in 26 samples) was chloridazon-desphenyl, which is a metabolite of pesticide chloridazon that is not registered on Estonian market and therefore not sold, which makes the determination of the origin of this compound complicated. It needs further research whether it is a remnant of Soviet times and slowly moving in the soil towards groundwater or if it is in use now.
This study was also reported in news portal Novaator and in environmental TV show Osoon
Moreover, there are hundreds of different pesticides and targeted screening methods usually look for compounds that are banned or known to be problematic. This study used the broader list of pesticides than regular yearly monitoring of pesticides indicating that broader coverage of potential pollutants is needed. Therefore, there is a need for the suspect and non-target screening methods for detecting more compounds and their metabolites.
In collaboration with Estonian Environmental Research Centre, our group has also contributed to studying and developing the non-target approach. Namely, Gunnar Printsmann developed in his master thesis suspect and non-target screening method for groundwater using high-resolution mass spectrometry which also included pollutants database. He found and confirmed a new industrial pollutant dibutyl phthalate in one sample from North-Eastern Estonia.
Our PhD student Jaanus is currently doing research in the group of Prof. Edwin De Pauw at the University of Liege in Belgium and he had a nice opportunity to take part in a 21st annual meeting of Belgian Society for Mass Spectrometry that was held on 29th of March in Liege. The meeting was organized in honour of Prof. Edwin De Pauw to summarize his work as he intended to retire after this year. Luckily for the mass spectrometric community, he will be actively involved in the research at least for four coming years.
Prof. Scott McLuckey opened the day with a presentation about strategies for achieving enzyme-like specificity in the gas-phase fragmentation of peptide and proteins. He showed different strategies how to cleave for example specifically at asparagine or lysine.
Prof. Andrea Sinz presented the results of the development of cleavable cross-linkers. Additionally, she pointed out that although cleavable crosslinkers are available on the market most of the groups determining the protein structures still use the noncleavable crosslinkers and do not take advantage of additional information provided by cleavable crosslinkers.
Dr. Valérie Gabelica presented the results of the studies of nucleic acid noncovalent complexes in native MS. She said that by knowing and studying the fundamentals of ESI processes one gets also a real insight into phenomena seen in different applications (in her case, nucleic acid noncovalent complexes). She also pointed out that unfortunately, scientific community publishes solely positive results which result in biased and non-universal theories.
Jaanus Liigand also had the possibility to present the results of our studies of standard substance free quantitation in LC/ESI/MS analysis and industry showed a great interest in our approach which could be beneficial for their needs (see the poster here).
It was a really nice day full of interesting presentations and discussions.
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.
