Trace metals zone refining

Even if sufficient sample size, in volume, may not be available, enrichment techniques that concentrate trace metals in microliter samples are sometimes quite useful because modern instrumental detection systems such as AAS, ICP-AES, ICP-MS, etc. do not need a large sample size. Moreover, if trace metals that have been separated from their major substances can be concentrated in an extremely small area of the polytetrafluoroethylene (PTFE) tube in HSCCC, this would be an ideal flow-injection analysis system for determination of inorganics. From this point of view, the recently developed pH-zone refining technique has great potential for enrichment, especially for instrumental inorganic trace analysis. 

E. Kitazume, N. Sato, and Y. Ito, A new preconcentration-detection method for trace metals by pH-zone-refining countercurrent chromatography, 1995 Pittsburgh Conference and Exposition on Analytical Chemistry and Applied Spectroscopy, 1995. 

Since the 1960s, activation analysis has been used intensively for determining trace elements in high-purity materials. Analysis of semiconductor materials, as well as of high-purity metals, obtained by zone refining, and of materials used in nuclear technology, has been one of the major fields of interest in activation analysis. Impurities are known to affect the properties of these materials, even when present in concentrations so low that they can barely be detected by other methods. 

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