Spectrometric Determination Of Gold Research Articles

Flame Atomic Absorption Spectrometric Determination of Gold After Solid Phase Extraction of its 2-Aminobenzothiazole Complex on Diaion SP-207

Flame Atomic Absorption Spectrometric Determination of Gold After Solid Phase Extraction of its 2-Aminobenzothiazole Complex on Diaion SP-207

Electrothermal Atomic Absorption Spectrometric Determination of Gold by Vapor Formation and in situ Trapping in Graphite Tubes

Gold was determined in ore samples following generation, separation, collection on a graphite cuvette inner wall, and atomization of its volatile species formed by combining an acidified sample solution with an aqueous sodium tetrahydroborate solution at room temperature. A detection limit of 2.6 microg L(-1) (3sigma) was obtained with a 5.0 mL sample volume. Precision of replicate measurements was typically 10% RSD. The overall efficiency of the volatile species generation, transport, and trapping process was 0.4%. Atomization of gold from Pd, Ir, Cu, Ag, and W coated graphite cuvettes, following by trapping of the gaseous volatile gold species on these surfaces, has been investigated. Pd coating was found to decrease the sensitivity. Five microg of Ir, 20 microg of Cu, 20 microg of Ag, and 5 microg of W were chosen as optimum masses. W treatment was the best one for sensitivity enhancement, having an improvement factor of 2.4. Silanization of glass surfaces significantly decreased memory effects; improved peak shapes were thus obtained for flow injection vapor generation atomic absorption spectrometry (FI-VGAAS). The method described in this study was used for the determination of gold in an ore reference material, Gold Ore (MA-1b), Canadian Reference Materials Program.

Spectrometric determination of gold, platinum and palladium in geological materials by d.c. arc plasma

A method for the separation and determination of Pt, Au and Pd in various geologcial materials by coprecipitation with tellurium and applying two spectrometric methods was considered in detail. Particular attention was paid to the influence of matrix elements on the determination of these metals. In one instance the metals were determined in solution by applying a U-shaped arc stabilized by an argon vortex and in the other in the solid sample by applying a vertical arc burning in a stream of argon-oxygen. The accuracy of the method was verified using the international reference standard SARM-7, and the results achieved were compared with published data.

Triethanolamine as a releasing agent for controlling interferences in the atomic absorption spectrometric determination of gold and its use as a collector for the flotation of gold

The interfering effects of a range of organic and inorganic species on the atomic absorption signal of gold have been investigated. These interferences were completely eliminated by adding 6 mmol l–1 triethanolamine (TEA) to both the sample and standard solutions. The role of TEA was extended to the extraction of gold, with 100% recovery, from aqueous solutions, using oleic acid as a surfactant at a pH of 0.5–2.0. A mechanism for the effect of TEA in the flotation and in the atomic absorption investigation was suggested. A simple, sensitive and rapid procedure for flatation and the atomic absorption spectrometric determination of gold in synthetic mixtures and natural waters was elaborated.

Modified decomposition procedure for the determination of gold in geological samples by atomic absorption spectrometry

A method is described for the atomic absorption spectrometric determination of gold in geological samples, involving a modified digestion procedure with sequential use of HBr—Br2 and aqua regia, [HCl—HNO3(3 + 1)]. The roasted sample (approximately 700 °C) was first treated with an HBr—Br2 mixture. Gold was extracted from the aqueous layer into isobutyl methyl ketone and the organic solvent containing gold was mixed with the original residue. The dried residue was again attacked with aqua regia. Gold was coprecipitated with potassium tellurite using tin(II) chloride solution. The precipitate was extracted into toluene and gold was stripped back into aqua regia solution for final nebulization into an air–acetylene flame. The method was applied to various reference materials with diverse matrices.