2. Result and Discussion
We used rocks from Altai-Sayan folded area, samples were prepared by grinding to the particle size of 200 microns.
Ore charge 1 g was placed in a corundum crucible and was claimed in a muffle furnace at the temperature 600-
650 for an hour. The sample was cooled down in the air, then 15 ml of hydrofluoric acid was added and
evaporated on electric furnace at the temperature 1800
C to wet residue. Freshly prepared aqua sample (15 ml) was
added to the residue, the mixture was evaporated up to the volume of 2-4ml at 1800
C. Then concentrated
hydrochloric acid (10 ml) was added to the mixture, it was evaporated up to the volume 2-4 ml at the temperature
1000
C. After mixture was cooled and diluted up to the volume of 10 ml of 4M hydrochloric acid. In order to
concentrate gold, we extracted obtained aqueous solution with 1 ml of 5 % di-n-octyl sulfide in toluene. High
sensitivity of method allows carrying out determination of lead, nickel and cobalt without preliminary extraction.
Method was controlled by measurement of the gold and lead concentration in reference materials(RM)(table 1)