Determination of trace element contaminants in food matrices using a robust, routine analytical method for ICP-MS

ICP-MS is a rapid analytical technique that shows potential for use in rout ine multielemental analysis in the food industry. However, in order to take advantage of its high speed of analysis, the anal ytical throughout should not be slowed down by a lengthy sample preparation step. On the other hand, a rapid wet ashing method may cause interferences due to the presence of residual carbon, particularly in the determination of As, Se and Pb. Arsenic and selenium measured by ICP-MS in samples where residual carbon is present may be determined with a higher value up to 30%. At the same time, Pb may be determined with a value of 10% lower. These carbon-related interferences were quantitatively studied. The study s hows that addition of a set concentration of isopropanol to wet ashed sampl es overcomes, interferences from residual carbon. The accuracy and reproduc tibility of the determination of As. Se and Pb by ICP-MS was improved. A rapid and robust analytical method for the trace determination of As, Cd, Hg, Pb, Al and Se, well-suited to the routine environment of the food anal ytical laboratory, has been developed.