A major concern in laboratories performing trace element determinations is sample contamination. Sensitivity can be enhanced for trace elements by using larger samples, but this approach may increase the risk of contamination due to the need for more involved preparation techniques. With the isolation of the sample from the laboratory environment, the potential for contamination is greatly reduced during sample decomposition. In this investigation, an environmental evaporation chamber (EEC) placed in a microwave digestion system was used for predigestion of biological and botanical samples prior to closed-vessel digestion. The EEC was also used for the evaporation of residual acid after completion of the digestion procedure. Data are presented for the analysis of standard reference materials along with detection limits and the results of a crosscontamination study for the described method.
Charles B. Rhoades, Keith E. Levine, Arthur Salido, and Bradley T. Jones, "Elemental Analysis Using Microwave Digestion and an Environmental Evaporation Chamber," Appl. Spectrosc. 52, 200-204 (1998)