On my third try, I was finally able to participate in Pittcon last week. This year Pittcon took place in person in Philadelphia, US. I was lucky enough to present our recent works in two presentations, one on quantitative nontarget screening (NTS) and the other on toxicity prediction for unidentified chemicals. You can find my […]
Tag Archives: ionization efficiency
12
Oct
Oct
After almost two years of zoom-only meetings, it was my great pleasure to last week get back to meeting fellow scientists in person at Intentional Conference on Non-Targeted Screening, Erding, Germany. The meeting was held in parallel in-person and online. The conference ran over four days with talks covering computational mass spectrometry, instrumental techniques for […]
10
Sep
Sep
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 […]
13
Jun
Jun
The last two weeks have been going under the title “thesis-thesis-thesis” in our group. This spring one BSc student and two MSc students from our group have defended their thesis: Sara Khabazbashi, Helen Sepman, and Thomas Ledbetter. Both Sara and Thomas have dug into the analytical standard free quantification for pollutants. Sara specifically focussed on metabolites of […]
25
Feb
Feb
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 […]
19
Oct
Oct
The difficulty in quantifying compounds in LC/ESI/HRMS arises from vastly different responsiveness of the compounds. At the same concentration, two compounds may yield very different signals due to the differences in the ionization efficiency of the compounds. The different responsiveness has made semi-quantitative non-targeted screening challenging. Still, research has been increasingly focussing on enabling the semi-quantification […]
25
May
May
Recently we have published a paper on advancement in predicting ionization efficiency in ESI and using this for estimating the concentration of pesticides in cereal samples without the need for analytical standards. In this paper, we explored the possibility to use machine learning for fast and accurate prediction of ionization efficiency. Previously we have carefully […]
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 […]
22
Jul
Jul
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 […]
24
Jun
Jun
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 […]
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