Papers by Keyword: GD-OES

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Authors: Steven James Lötter, Walter Purcell, Johann T. Nel

Glow Discharge Optical Emission Spectroscopy (GD-OES) is an analytical technique mainly used in the analysis of solid metallic samples. The technique requires a conductive sample as the analyte serves as the cathode when generating the glow discharge plasma. GD-OES is useful for both bulk quantification and depth profiling of thin layers of conducting materials. The objective of this study was to develop a new sample support matrix for the preparation of conductive pressed pellets suitable for the analysis of non-conducting materials with GD-OES. In previous work non-conducting powders, such as uranium oxide, have been mixed with fine metal powders such as copper, silver or tantalum. Another solution has been to use a quick setting, conductive thermoplastic, such as diallyl phthalate impregnated with copper, as support. Both of these methods are, however, expensive and fairly time consuming. Graphite, a cheap, readily available conductive powder, proved not to form a strong enough pellet to withstand the conditions required during the GD analysis. This limitation was overcome by the addition of a binding agent, bakelite, to produce a relatively cheap, conductive matrix for the analysis of non-conducting powders. Spectroscopically pure zirconium oxide was used as a reference material and mixed with various quantities of graphite and bakelite powder. Two distinct regions of linearity were obtained. Samples with less than six percent zirconium yielded a gradient of 0.0011 with an R2 value of 0.9949. Samples with higher zirconium content yielded a gradient of 0.0042 with an R2 value of 0.9991. These results indicate the suitability of this sample matrix for analysis of zirconium materials by GD-OES.

Authors: Gábor Lévai, Melinda Godzsák, Alfred Ender, Róbert Márkus, Tamas I. Török
Abstract: Nowadays the most commonly used baths for hot-dip galvanizing are the ones which contain about 0.1 ... 0.2% of aluminium. Besides aluminium, the effects of the addition of small quantities of titanium (up to 0.0005%) to the bath have recently been studied in detail by Culcasi et al. [2]. They proved the strong impact of adding a small amount of titanium on the development of the iron-zinc layer, which influences primarily the building up of the intermetallic compound film Fe2Al5 on the surface of the steel piece in contact with the molten zinc. This aluminium-alloyed hot-dip bath with titanium usually does not form a nicely coloured surface [. Therefore, our experiments were limited to test only the effect of adding titanium to the molten zinc which contains only traces of aluminium in order to study the impact of titanium on surface colouring using GD-OES spectrometry.
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