Simultaneous speciation analysis of As, Cr and Se in the bio-accessible fraction for realistic risk assessment of food safety

A simple and fast method was developed for risk assessment of As, Cr and Se in food, which is demonstrated here using three cooked and uncooked rice samples (basmati as well as organic white and brown rice). The bio-accessible fraction was first determined through on-line leaching of rice mini-columns (maintained at 37 oC) sequentially with artificial saliva, gastric juice and intestinal juice while continuously monitoring potentially toxic elements (As, Cr and Se) by inductively coupled plasma mass spectrometry (ICPMS). Then, a new ion chromatography method with on-line detection by ICPMS was developed for the simultaneous speciation analysis of As, Cr and Se in the bio-accessible fraction to determine the portion of these elements that was actually toxic. Using gradient elution, four As species (As(III), As(V), monomethylarsonic acid and dimethylarsinic acid), two Cr species (Cr(III) and Cr(VI)) and two Se species (Se(IV) and Se(VI)) were separated within 12 min. The simultaneous speciation analysis of ...