Paper Title
13C and 18Ο as Authenticity Tracers to Detect Olive oil Fraud

Abstract
Samples of olive oils from Chalkidiki, Southern (Crete Island) and Central Greece as well as from the Peloponnese (Messinia and Lakonia) and the Ionian Islands were analyzed for isotopic ratios and of δ13C (‰ vs V-PDB) and δ18O (‰ vs V-SMOW), to detect potential fraud. The examination of carbon and oxygen isotopes δ13C (‰ vs V-PDB) and δ18O (‰ vs V-SMOW) in olive oils, can determine the authenticity of olive oil and the potential impurities with other oils. Based on the 13C and 18O values, all studied samples were separated into groups. The analysis of the δ18O isotope shows that the olive oils from the Ionian Islands are distinct from those of the Peloponnese and Crete. This is because the oxygen isotope is primarily influenced by the temperature and the precipitation levels of each region. Therefore, this differentiation between the environmental data justifies a division between Northern and Southern olive oils. The δ18O values of olive oil samples from Greece are similar to those from Italy, Spain, and Turkey, indicating comparable climatic conditions in these countries. Also, this study aimed to perform a preliminary chemical characterization of Chalkidiki extra virgin olive oils using rare earth elements (REEs). Keywords - δ13C,δ18O, Fraud, Olive Oil, REEs, Stable Isotopes.