engleski

Screening TLC Determination of Metal Components in Alloys after Anodic Sampling

This work reports screening determination of alloys. Method involves anodic sampling, thin-layer chromatography separation on precoated cellulose layer and quantification by video densitometry. Pure metals, as they come from the rafinery, are seldom suitable for producing jewellery coins, or other forms of practical or artistic expression. Consequently, the alloying of metals is of great importance, because it is one of the best ways of altering their properties. Nowdays, as in the past, considerable emphasis is laid on the correct selection of alloys because the properties of an article depend upon the composition. The original composition of alloys has to be studied because this knowledge may indicate the technology used in their production ; according to these the antique statues can be devided into period groups, and alloys can be phase classified. The composition of the metal at the surface of the alloy may be very different from that in the interior, too, and the presence of impurites can effect both the microstructure and the corrosion properties at the surface of alloy. Often is very important to use analytical method to solve a particular problem that allows non destructive sampling. Micro-anodic dissolution of alloy allows in situ sampling of metal artefact with minor destruction. Subsequent determination of alloy constituents by TLC enables fast sceening analyse. Computer-assisted optimisation was used for the determination of the mobile phase composition. After development the spots were visualised by spraying chromatograms with quercetine and dimethylglyoxim solutions. Image capturing and data evaluation were performed with the CAMAG Video Documentation System. The chromatograms were captured under white light by highly sensitive 3CCD colour video camera. Image acquisition, processing and archiving were controlled by Video Store 2 Verion 2.30 documentation software running under Windows.The validation of method by determination of precision, limit of detection and limit of quantification was carried out.

alloys; anodic sampling; TLC; video.densitometry

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