Multivariate analysis applied to trace and ultra-trace elements in Italian potable waters determined by INAA

In this paper we have applied a chemometric treatment for investigating and comparing the element composition in potable water samples collected in two Italian urban areas, Rome and Florence, and analyzed by Instrumental Neutron Activation Analysis. The spectrum of drinkable tap Roman water shows very low limits of potentially toxic elements (Sb, Hg, Cr, Ni, etc.); in particular, they are present at levels below the values suggested by the European laws and the World Health Organization (WHO) guidelines. Further, it is also evidenced that the elemental composition is quite similar to that of uncontaminated natural waters. According to the Florence drinking water element characterization, the concentration values show an almost good situation except for Al. Comparing the two water systems a higher level of I, Se and some anthropogenic elements (Cu, Na, Zn) is found in Florence samples. A multivariate statistical treatment such as canonical analysis was performed for identifying the contribution of each element to the chemical composition of Roman water.