Evaluation of elemental distributions in wild- caught and farmed Pangasius sp. using pattern recognition techniques

The concentrations of Na, Mg, K, Ca, Cr, Fe, Ni, Cu, Zn, As, Se, and Pb in various tissues of
Pangasius sp. were determined using microwave-assisted digestion/inductively coupled plasma–mass
spectrometry. The clustering tendency related to elemental patterns associated with tissue variants and
fish habitats were explored using hierarchical cluster analysis and principal component analysis. The
results revealed that the general elemental accumulation pattern was strongly dependent on the type
of tissue, whereas latent deviations within particular tissue samples can be linked to the natural
variability between wild-caught and farmed fish. The inherent elemental patterns allowed us to
differentiate between those wild-caught and farmed fish through linear discrimination analysis with
100% precision. In terms of food safety, the elemental concentrations in edible muscle were found to
be far below the legal limits, as the associated health risks at the 90th percentile were well within
tolerable regions, although wild-caught fish were found to pose a higher risk.