Abstract:

Тributylphosphate (TBF) and dioctylsulfide (DOS) in liquid organic diluents are well known extractants used in analytical chemistry of gold. The study of the extraction of gold by these reagents in higher carboxylic acids (HCA) and paraffin as well as a comparison of their extraction capacities by replacing the solvent are of great interest. Extractant for development of X-ray fluorescence analysis technique for gold in various objects was selected by studying the extraction of gold by tributylphosphate and dioctylsulfidein low melting diluents. It was shown that, when using kerosene for dilution, tributylphosphate quantitatively extracted gold СHCl=0.5-3.5 M. Extractant containing 5-20 % TBF-paraffin-HCAdid not provide quantitative extraction of gold. Recovery of gold for 5 % DOS-HCA-paraffinat СHCl =0.5-3.0 M reached 98-99%. Using the method of equilibrium shift,composition of the extracted gold complex with DOS was proposed: AuCl3 - R2S. This extractant can be used for development of X-ray fluorescence method for determination of gold.Calibration curve forX-ray fluorescence determination of gold in extracts is linear in the range of mass concentrations4.0 x 10-3-1.7 x 10-1 % (w/w). Detection limit of the method is 5.0 x 10-4 % (w/w).

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