THE INFLUENCE OF ORGANICS ON THE DETERMINATION OF GOLD, SILVER AND COPPER BY ATOMIC-ABSORPTION SPECTROPHOTOMETRY

Direct analysis of aqueous solutions by atomic absorption spectrophotometry (AA) is practised widely in the gold mining industry. It is shown here that the presence of organics at concentrations as low as 5 p.p.m. could decrease the AA reading of metal concentrations significantly. This implies that the real metal concentration of complex leached solutions containing organics, cannot be determined by AA only. A linear relationship was observed between the real and recorded metal concentration in dilute solutions. A novel method, based on this linear relationship, is proposed whereby a known quantity of the metal can be added to the real solution, and the AA readings before and after the addition used to correct the metal concentration. These results are especially relevant to operations such as CIP plants where organics are often present in solution. © 1990.