Towards the development of a multi-element analysis by ICP-oa-TOF-MS for tracing the geographical origin of processed tomato products

In this preliminary work, the mineral composition (Li, Be, Al, V, Cr, Mn, Co, Cu, Zn, Ga, As, Rb, Sr, Ag, Cd, In, Cs, Ba, Tl, Pb, Bi, and U) of forty-one processed tomato samples, coming from three different countries (Italy, China and Spain), was investigated by Inductively Coupled Plasma orthogonal acceleration Time-of-Flight Mass Spectrometer (ICP-oa-TOF-MS), exploiting the characteristic of simultaneity of the measurements that is distinctive of this type of instrument. The large amount of data achieved through multi-element analysis was statistically processed by Linear Discriminant Analysis (LDA), and a good geographical origin discrimination of tomato samples (99.9% of cases correctly classified) was obtained. Li and Sr could distinguish Chinese from EU samples, while Co and Cu were able to differentiate Spanish tomato from the other ones. Moreover some elemental ratios (Li/Cr, Mn/Cu, Co/Cu and Sr/Cd) allowed a better clusters separation than single elements. rk is still in progress, but preliminary results indicates that ICP-oa-TOF-MS could be considered a fast, precise and accurate instrument for multi-element determinations to be used for tracing tomato provenance.