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DETERMINATION OF METALS IN COMPOSITE DIET SAMPLES BY ICP-MS
Citation:
Morgan, J N., O. Akinbo, R. Fernando, AND E. D. Pellizzari. DETERMINATION OF METALS IN COMPOSITE DIET SAMPLES BY ICP-MS. Presented at AOAC International Meeting, Houston, TX, September 26-30, 1999.
Description:
In order to assess an individual's toal exposure to contaminants in the environment, it is essential that the contribution of dietary exposure be quantified. As a result, USEPA's National Exposure Research Laboratory has initiated a program to develop methods to measure chemical pollutants in dietary samples collected from individuals. Previous efforts have utilized ICP-AES and GFAAS techniquesw for determination of metals in composite diets. However, there is often a trade-off between sensitivity and sample throughput with these techniques. ICP-MS offers sensitivity comparable to or better than GFAAS while retaining sample throughput comparable to ICP-AES. This study evaluated the applicability of ICP-MS techniques to determination of metals in composite diets. An ICP-MS method for determination of Al, Ba, Cd, Cr, Cu, Pb, Mn, Ni, V and Zn is presented. The procedure utilizes atmospheric pressure microwave digestion to solubilize analytes in homogenized food samples followed by ICP-MS analysis. Recovery of certified elements from SRMs ranged from 92-119% with rSD ranging from 0.4 - 1.9%. Recovery of elements from fortified composite diet samples ranged from 75-129% with RSDs ranging from 0 - 11.3%. MDLs ranged from 1 -1733 ppb, with high values due to significant amounts of certain elemnts naturally present in foods. Results of this study demonstrate that low resolution ICP-MS provides precise and accurate measurement of the elements tested in composite diet samples.