Determination of toxic and potentially toxic elements in rice and rice-based products by inductively coupled plasma-mass spectrometry

A study was undertaken to quantify the concentration of toxic and potentially toxic elements in samples of rice, rice crackers, rice noodles, infant cereals and rice vinegar available in the Argentine market. The determination of nine elements, namely, As, Cd, Cr, Hg, Ni, Pb, Sb, Se, and Zn in 29 samples was performed by inductively coupled plasma-mass spectrometry. Element concentrations spanned the range (ng g(-1)): As, 67-858; Cd, < 0.2-24.0; Cr, 36.6-937; Hg, < 50; Ni, 38.6-1040; Pb, < 2.0-139; Sb, < 3.0-24.7; Se, < 8.4-178 and Zn, 129-32400. Mercury was not detected in any of the analyzed samples. The highest concentration (32.4 mu g g(-1)) was found for Zn in infant cereals that according to the label were added by the manufacturer. To assess accuracy, NIST 1568a rice flour was analyzed and results were in good agreement with certified values.