The determination was studied of Al, B, Be, Cd, Ca, Co, Cu, Mg, Mn, Mo, Pb, Si, Sn, V, Cr, Ni, and Fe as trace level impurities in uranium compounds by ICP-AES after extraction of uranium with three different mixtures of di-(2-ethyl-hexyl) phosphate (D2EHP) and tri-(2-ethyl-hexyl)-phosphate (T2EHP) in solvents like toluene, carbon tetrachloride, hexane and cyclohexane. The study was carried out in presence of different concentrations of HCl and HNO(3). A single extraction with D2EHP in cyclohexane using nitric acid as matrix was sufficient to reduce the U(3)O(8) concentration from 100 g/l to 100 microg/ml. The ICP-AES instrumentation applied, allowed the determination of metal concentrations ten-times lower than those usually found in nuclear grade U(3)O(8). To check the efficiency of the extraction and the accuracy of the proposed method, Certified Reference Materials were used in the dissolution and extraction steps. The method described can be used for the determination of trace metals in nuclear grade U(3)O(8).

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Sequential inductively coupled plasma atomic emission spectrometry was used to determine Ti and Th as minor elements and Zr and Ce as major elements in zirconia-based ceramics. Spectral interferences, matrix and acid effects were studied for several Th, Ti, Zr and Ce wavelengths. A method was developed for the determination of both major and minor elements in the same solution. Limits of detection (LODs) for minor elements in ceramic materials were 15 ppb for Th II 283.231 nm and 30 ppb for Th II 326.267 nm, 2 ppb for Ti II 334.941 nm and 336.121 nm. These LODs were well below the required determination values for these two metals in their matrices. Decomposition of the samples with hydrofluoric, hydrochloric and sulfuric acids was adequate for the determination of all elements and good agreement with values for a Japanese sample of known composition was obtained.

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The reliability of results obtained from chemical analysis of environmental samples is related to the sample collection and preparation techniques. A succession of stages is required to obtain a result that is both accurate and representative of the initial material. The task begins by taking the appropriate precautions during collection of the liquid and solid samples, and during their later shipment to the laboratory. The environmental conditions in the laboratory where the sample will be prepared are important, as is the quality of the apparatus, containers, glassware, and reagents that are usually used. The preparation of solid waste samples requires the selection of appropriate digestion procedures, apparatus that is of high enough quality to resist the aggressiveness of some inorganic acids, and convenient systems of security for the procedures that are carried out. The information produced by the laboratory should have a high degree of reliability. For this reason, the procedures used usually permit the results obtained to be guaranteed. The more important procedures include the use of certified reference materials (CRM) and participation in interlaboratory programs. Some organizations, for example the United States Environmental Protection Agency (USEPA), have developed and distributed procedures for environmental sample preparation, which are used by many laboratories as normalized methods of reference.