Multi-Element Analysis of Sicilian Citrus Fruits from Volcanic and Non-Volcanic Areas for Geographical Authentication and Food Safety Assessment

This study investigated the elemental composition along the soil–plant continuum of Sicilian citrus fruits grown in volcanic (Stromboli and Etna) and non-volcanic (Marsala) areas. Following microwave-assisted acid digestion, macro- and trace elements were quantified via ICP-MS in soils, whole fruits, peel, pulp, and juice. Citrus fruits from volcanic areas generally showed higher concentrations of K, P, Fe, and Al than those from Marsala. Potentially toxic elements in edible fractions were generally low, with Pb and Cd below the applicable regulatory limits. Elemental partitioning showed higher measured concentrations of several potentially toxic elements in the peel, with lower concentrations in pulp and juice. Principal Component Analysis (PCA) revealed separation of samples according to geographical origin, while Linear Discriminant Analysis (LDA) achieved complete classification within the investigated dataset, with K, Al, Mg, and Ni. These findings indicate that elemental fingerprinting may support geographical characterization, together with nutritional and toxicological assessment.