TY - JOUR

T1 - Elucidating the spatial distribution of organic contaminants and their biotransformation products in amphipod tissue by MALDI- and DESI-MS-imaging

AU - Raths, Johannes

AU - Pinto, Fernanda E.

AU - Janfelt, Christian

AU - Hollender, Juliane

N1 - Funding Information: We acknowledge financial support of the Swiss National Science Foundation ( 200020_184878 ). We thank Marcus Lorensen (Copenhagen University), Susanne Ulbrich and Anna-Katharina Hankele (ETH Zürich, AgroVet-Strickhof) for helpful discussions and use of their facilities for cryosectioning, respectively. We thank Syngenta Group Co., Ltd. for the provision of reference standards. Graphics were partially created using https://biorender.com . Funding Information: We acknowledge financial support of the Swiss National Science Foundation (200020_184878). We thank Marcus Lorensen (Copenhagen University), Susanne Ulbrich and Anna-Katharina Hankele (ETH Zürich, AgroVet-Strickhof) for helpful discussions and use of their facilities for cryosectioning, respectively. We thank Syngenta Group Co. Ltd. for the provision of reference standards. Graphics were partially created using https://biorender.com. Provided are SI A (main SI section) and the excel sheet SI B (holds measured concentrations and explanation of metaspace file names). ImzML files are uploaded to the metaspace database and are openly available at https://metaspace2020.eu/project/raths-2023. Publisher Copyright: © 2023 The Authors

PY - 2023

Y1 - 2023

N2 - The application of mass spectrometry imaging (MSI) is a promising tool to analyze the spatial distribution of organic contaminants in organisms and thereby improve the understanding of toxicokinetic and toxicodynamic processes. MSI is a common method in medical research but has been rarely applied in environmental science. In the present study, the suitability of MSI to assess the spatial distribution of organic contaminants and their biotransformation products (BTPs) in the aquatic invertebrate key species Gammarus pulex was studied. Gammarids were exposed to a mixture of common organic contaminants (carbamazepine, citalopram, cyprodinil, efavirenz, fluopyram and terbutryn). The distribution of the parent compounds and their BTPs in the organisms was analyzed by two MSI methods (MALDI- and DESI-HRMSI) after cryo-sectioning, and by LC-HRMS/MS after dissection into different organ compartments. The spatial distribution of contaminats in gammarid tissue could be successfully analyzed by the different analytical methods. The intestinal system was identified as the main site of biotransformation, possibly due to the presence of biotransforming enzymes. LC-HRMS/MS was more sensitive and provided higher confidence in BTP identification due to chromatographic separation and MS/MS. DESI was found to be the more sensitive MSI method for the analyzed contaminants, whereas additional biomarkers were found using MALDI. The results demonstrate the suitability of MSI for investigations on the spatial distribution of accumulated organic contaminants. However, both MSI methods required high exposure concentrations. Further improvements of ionization methods would be needed to address environmentally relevant concentrations.

AB - The application of mass spectrometry imaging (MSI) is a promising tool to analyze the spatial distribution of organic contaminants in organisms and thereby improve the understanding of toxicokinetic and toxicodynamic processes. MSI is a common method in medical research but has been rarely applied in environmental science. In the present study, the suitability of MSI to assess the spatial distribution of organic contaminants and their biotransformation products (BTPs) in the aquatic invertebrate key species Gammarus pulex was studied. Gammarids were exposed to a mixture of common organic contaminants (carbamazepine, citalopram, cyprodinil, efavirenz, fluopyram and terbutryn). The distribution of the parent compounds and their BTPs in the organisms was analyzed by two MSI methods (MALDI- and DESI-HRMSI) after cryo-sectioning, and by LC-HRMS/MS after dissection into different organ compartments. The spatial distribution of contaminats in gammarid tissue could be successfully analyzed by the different analytical methods. The intestinal system was identified as the main site of biotransformation, possibly due to the presence of biotransforming enzymes. LC-HRMS/MS was more sensitive and provided higher confidence in BTP identification due to chromatographic separation and MS/MS. DESI was found to be the more sensitive MSI method for the analyzed contaminants, whereas additional biomarkers were found using MALDI. The results demonstrate the suitability of MSI for investigations on the spatial distribution of accumulated organic contaminants. However, both MSI methods required high exposure concentrations. Further improvements of ionization methods would be needed to address environmentally relevant concentrations.

KW - Aquatic invertebrates

KW - Bioaccumulation

KW - Cryosectioning

KW - Dissection

KW - Gammarus pulex

KW - Micropollutants

KW - Whole body cross sections

U2 - 10.1016/j.ecoenv.2023.115468

DO - 10.1016/j.ecoenv.2023.115468

M3 - Journal article

C2 - 37738825

AN - SCOPUS:85171871247

VL - 264

JO - Ecotoxicology and Environmental Safety

JF - Ecotoxicology and Environmental Safety

SN - 0147-6513

M1 - 115468

ER -