Trace metals ultratrace analysis

Today, as a direct solid-state analytical technique, dc GDMS is more frequently applied for multi-element determination of trace contaminants, mostly of high purity metallic bulk samples (or of alloys) especially for process control in industrial laboratories. The capability of GDMS in comparison to GD-OES (glow discharge optical emission spectrometry) is demonstrated in a round robin test for trace and ultratrace analysis on pure copper materials.17 All mass spectrometric laboratories in this round robin test used the GDMS VG 9000 as the instrument, but for several... 

The majority of the works with HgCFMEs focused on the anodic stripping of metals [127]. However, our works have been mainly focused on the determination of organic molecules that show the ability of adsorption on mercury [119-121], for example pteridines. Therefore, those molecules can be primarily preconcentrated on HgCFMEs and, subsequently, determined by cathodic stripping techniques. This procedure is described like adsorptive stripping voltammetry and it is a very interesting technique for trace and ultratrace analysis due to its... 

Stoeppler, M., Valenta, P. and Nurnberg, H.W. (1979). Application of independent methods and standard materials an effective approach to reliable trace and ultratrace analysis of metals and metalloids in environmental and biological matrices, Fres. Z. Anal. Chem. 297, 22-34... 

The analysis of PGM is, with few exceptions, a field of trace and ultratrace analysis. All necessary procedures must be carried out with extreme precision. During sample preparation, the strong tendency of PGM to form complexes as well as their tendency to be reduced must be considered. Conditions causing a reduction must be avoided since they inevitably lead to metal precipitations in solution or on the wall of the vessels. In weakly acidic, neutral, and alkaline solutions, PGM form less stable aquo-hydroxo complexes resulting in difficult-to-control, usually irreversible precipitations of hydroxides, oxohydrates, and metal particles. 

Kenneth Johnson is a Senior Scientist at the Monterey Bay Aquarium Research Institute. His research interests are focused on the development of new analytical methods for chemicals in seawater and application of these tools to studies of chemical cycling throughout the ocean. His group has developed a variety of analytical methods for analyzing metals present at ultratrace concentrations in seawater. His expertise lies in trace metal analysis and instrumentation. The creation of reference materials to calibrate these instruments is important for the production of long-term, high-precision datasets. Dr. Johnson has participated on the NRC Committee on Marine Environmental Monitoring and the Marine Chemistry Study Panel. 

In analogy to sample introduction by hydride generation, it is also possible to perform mercury trace and isotope analysis by reducing Hg compounds to the metal using the cold vapour technique or the determination of iodine at the ultratrace level (after oxidation with 70 % perchloric acid of iodide to iodine) via the gas phase. 

Trace and Ultratrace (Bulk) Analysis of Metals and Alloys... 

LA-ICP-MS is suitable for the direct analysis of materials such as metals, semiconductors, ceramics and insulators at trace and ultratrace levels (detection limits 1 ng g ) without sample preparation. The MS detection mode makes it possible isotope analysis and also isotope dilution methods using... 

The analysis for metal ultratraces requires extremely clean laboratories [2]. This, in turn, requires the use of a carefully filtered air supply. All reagents used must be certifledly ultrapure and their purity be preserved. Deionized water should be carefully controlled to ascertain the absence of contaminating traces —this requires all technicians to exercise care to avoid contamination by their hair, skin, cosmetics, excretions or even the exhaled air. A strict control of the analytical blank [3] Is obviously another must in this type of analysis to avoid spurious results In the determination of some trace or ultratrace analytes. 

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