Tag Archives: ESI

What is the potential risk of the compounds detected in water samples? Combining concentration and toxicity

How do you know which of the compounds detected in suspect or non-targeted screening is most likely to cause an adverse effect? Which is most toxic? Which is present in the highest concentration? Which is having a concentration close to a toxic endpoint? This is exactly what we are answering in our latest research in […]

Benchmarking of the quantification approaches for the non-targeted screening

Non-targeted screening with liquid chromatography-electrospray high-resolution mass spectrometry (LC/ESI/HRMS) is revealing hundred to thousands of contaminants in the water. We have recently proposed a way to quantify these contaminants based on the estimated LC/ESI/HRMS ionization efficiencies. But how to know how well such tools are performing? Well, we need to compare with classical methods that are […]

What is non-targeted analysis and why it should go quantitative?

In June at HPLC conference I had a super nice possibility to explain what is non-targeted screening and why it should be developed into a quantitative method. Now, this video is available for all of you. I thank a lot Alasdair Matheson from LC&GC, who invited me to do the video, LCGC video teem, and HPLC […]

Solutions and Workflows in (Environmental) Molecular Screening and Analysis (SWEMSA) conference

At the end of October, a three-day SWEMSA conference on non-targeted analysis took place in the Erding, close to Munich, Germany. On the conference representatives from different non-targeted communities came together to present the last progress made in the field. The focus was very strongly on the data analysis side but also method development and […]

We are happy to introduce: Dr. Piia Liigand and Dr. Jaanus Liigand

Last week two of our PhD students, Piia Liigand and Jaanus Liigand, successfully defended their PhD theses. Both Piia and Jaanus worked intensively and successfully on understanding the ionization process in electrospray ionization source (ESI) and applying this knowledge for quantifying compounds with LC/ESI/MS without standard substances. Congratulations to the fresh doctors! Piia is continuing […]

Ionization efficiency of an oligopeptide can be predicted based on its amino acid composition

Ionization efficiency of oligopeptides does depend on the chemical composition of the peptide. Longer oligopeptides generally obey higher ionization efficiency; however, for peptides containing more than seven amino acid the ionization efficiency values are relatively similar. Also, the ionization efficiency values of the amino acids can be used to estimate the ionization efficiency of a […]

We presented standard substance free quantitation in HPLC2019

Last Thursday the HPLC2019 meeting finished. The conference was this year held in Milano, Italy and incorporated more then 300 talks. I had a chance to give a keynote lecture on the quantification of metabolites from green tea with LC/MS without the need for standard substances. The main focus of the conference was on the […]

67th ASMS Conference on Mass Spectrometry and Allied Topics

From 1st to 6th of June, two PhD fellows Piia Liigand and I presented our recent results at 67th ASMS annual conference in Atlanta, USA. The conference was kicked off with a plenary lecture by Prof. Mark Z. Jacobson on the topic of “Transitioning the World Energy for All Purposes to Stable Electricity Powered by […]

Eurachem 2019 in Tartu was a success

Last week from 20th to 21th of May Tartu hosted Eurachem yearly workshop with the topic of “Validation of targeted and non-targeted methods of analysis”. These two days were filled with exciting presentations, insightful discussions and joy of meeting new and old friends and collaboration partners. What is happening in the field of non-targeted analysis? Eurachem […]

Mari submitted her master’s thesis on reactions in charged droplets

Today our master’s student Mari Ojakivi submitted her thesis. She studied the reactions between 7 aldehydes and 4 nitrogen bases in charged droplets. For this, she built an in-house built electrospray system to generate the charged droplets. Mostly imines were observed as reaction products, but also amides were found in some reactions. For comparison, the same reactions […]