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 […]

Thesis-Thesis-Thesis: From PCB Metabolites Through PFOS to Reactions in Charged Droplets

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 […]

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 […]

NORMAN interlaboratory comparison on semi-quantitative LC/HRMS

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 […]

Cyclic-IMS/HRMS installed in MassSLab at Stockholm University

In September a state-of-the-art cyclic-ion mobility high-resolution mass spectrometer (cyclic-IMS) will be installed in the MMK/ACES joint Mass Spectrometry Laboratory (“MassSLab”). This is the first cyclic-IMS in Sweden and one of the few in Europe. It is envisioned that this new instrument will open up exciting opportunities for novel experimentation while fostering new collaborations both […]

Emma and Louise graduating

Last Friday two talented BSc students, Emma Palm and Louise Malm, in our group, defended their BSc thesis. They both focussed on making the LC/ESI/HRMS quantitative for the non-targeted analysis where standard substances are either not available or even the structure is not unequivocally identified. The thesis project of Louise focussed on kicking off the […]

Quantification for non-targeted LC/MS screening without standard substances

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 […]

MSForum in Vienna

Last week the 17th MassSpec forum took place in Vienna with two days full of exciting mass spec talks. The conference was open by Prof. Dr. Kevin Pagel who introduced the work of his group that has focussed on revealing the structure of sugar molecules in the gas phase. His group has made great use […]