Abstract
A sensitive and rapid method for the determination of gold in ores by atomic absorption spectrometry was investigated.
A sample (?1g) was decomposed with aqua regia. Silica was removed by filtration. The filtrate was converted to about a 20ml of 1.5N HCl solution, and was shaken with 5ml of methyl isobutyl ketone (MIBK). The MIBK extract was washed successively with 7 and 3ml portions of 1.5N hydrochloric acid equilibrated with MIBK before use, and was introduced into air-acetylene flame and the absorption readings were taken at 2428Å.
The proposed method was applied to the determination of gold above 0.2ppm in ores. The results obtained for various practical samples agreed well with those by the classical fire assay method requiring a large amount sample in one analysis. The other constituents usually contained in ores did not interfere. The sensitivity and the limit of detection of this method were, respectively, 0.01μg/ml/1% and 0.01μg/ml.
