Marios G. Kostakis is Assistant Professor at the National and Kapodistrian University of Athens. He is also a member of the Association of Greek Chemists, the Hellenic Mass Spectrometry Society, and the EURACHEM Working Group for Method Validation. He received his B.Sc. in Chemistry, M.Sc. in Chemical Analysis & Quality Control, and Ph.D. in Analytical Chemistry, all from the University of Athens, in 2009, 2012, and 2019, respectively. His general research interests include Method Development; Method Validation, uncertainty in analytical measurements; Atomic Absorption Spectrometry & Atomic Emission Spectrometry; Reversed Phase Liquid Chromatography (RP-LC) and Hydrophilic interaction chromatography (HILIC); Gas Chromatography; Mass Spectrometry; Quality Assurance in Analytical Chemistry & ISO 17025.