Stripping Chronopotentiometry: An Alternative Method for the Determination of Gold in Geological Samples

A stripping chronopotentiometric method was developed for reliable determination of gold in geological samples. Gold in gold ore and steam sediment samples was determined by constant current film stripping chronopotentiometry at a bare glassy carbon working electrode. The following optimum conditions were obtained: 0.5 M hydrochloric acid as a supporting electrolyte, an electrolysis potential of –0.6 V vs. saturated calomel electrode (SCE), an electrolysis time of 2 min and a constant oxidative current of +4 μA. A linear concentration range was obtained from 1.0 to 20 mg/l. The detection limit was 0.27 mg/l (n = 10) and the relative a standard deviations of 1.0 mg/l Au(III) was 2.8 % (n = 10). In order to check the analytical accuracy, standard solution was spiked in a sample and the recoveries were found at 100.1 to 105.8 %. The results revealed that the quantity of gold in gold ore and sediment were 0.6 to 3.3 % and 0.9 to 1.2 %, respectively