Category Archives: Research

MultiConditionRT: a new tool to predict retention times in a wide range of chromatographic conditions

Retention time is a crucial information for structural elucidation of unknown chemicals in non-targeted analysis using liquid chromatography coupled to high resolution mass spectrometry via electrospray ionization (LC/ESI/HRMS). Most of the predictive models of retention time are developed in limited chromatographic conditions, mostly for reversed phase and HILIC mode and in acidic conditions. However, retention […]

Welcome to Kruvelab – meet Masoumeh

Masoumeh Akhlaqi is a Master student in analytical chemistry at Stockholm University. For her Master’s thesis, she is using two-dimensional ion mobility to separated, distinguish or identify isomeric compounds,  specifically isomeric pesticides in food samples. For this purpose, she is using cyclic ion mobility instrument coupled to liquid chromatography and Time-of-Flight mass analyzer.

Can we quantify chemicals if we do not know their structure? Yes, we can!

Non-target analysis with LC/ESI/HRMS is increasingly used to detect thousands of chemicals in environmental samples. However, most of these chemicals are never confidently identified nor quantified. This in turn means that they are ignored in risk assessments. In our recent paper, we address this issue by modeling the response factor for chemicals without the need […]

Welcome Lisa!

Lisa is a second year Master’s student with a background in environmental chemistry. For her Master’s thesis, Lisa is working on the exciting field of non-targeted screening and developing a prioritization method for unidentified compounds in the MS spectra of real life samples. In order to give compounds priority ranks, she is using in-house built […]

Welcome, Pauline!

Pauline Petitfour is an intern from Sigma-Clermont engineering school in Clermont-Ferrand (France). She is studying organic and analytical chemistry and she is joining our group for four months internship. She will evaluate and model the extraction efficiency for most common solid phase extraction workflows used in non-targeted screening. Bienvenue Pauline!

Welcome back, Helen!

After spending six months in South-Korea as an exchange student and finishing her Master’s degree from University of Tartu, Helen Sepman is back in our group. Helen was part of Kruvelab in Stockholm University in October 2020-January 2021, when she studied protomer formation of caffeine metabolites with cyclic-IMS as an intern. She was one of […]

Welcome to Kruvelab – meet Emma and Louise

  Emma Palm and Louise Malm started their master thesis in our group. Emma and Louise are master students in analytical chemistry at Stockholm University and they did their bachelor’s thesis in our group. Emma Palm will work with cyclic ion mobility for the identification of isomeric compounds based on the collision cross-section. This will […]

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 […]