1. Helmholtz Center Munich, German Research Center for Environment Health, Research Unit Analytical BioGeoChemistry, Neuherberg, Germany
2. IIS-Fundacion Jimenez Diaz UAM, Madrid, Spain
3. University of Skopje, Faculty of Medicine, Skopje, Macedonia
4. Department of Internal Medicine, Nephrology Division, Ghent University Hospital, Ghent, Belgium
5. German Center for Diabetes Research (DZD), Neuherberg, Germany
6. Technical University Munich, Chair of Analytical Food Chemistry, Freising-Weihenstephan, Germany