Determination of Gold in Gold Ores by Inductively Coupled Plasma-Optical Emission Spectrometry with Carbon-loaded Foam Plastic Adsorption

The method of carbon-loaded foam plastic adsorption has good adsorption properties of gold, but is only suitable for filtration adsorption with complicated analytical procedures. Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) with carbon-loaded foam plastic adsorption was used to determine the content of gold in gold ore and is described in this paper. The gold ore sample was firstly burned at 650℃ for 2 h, followed by dissolution with 50% aqua regia and 10% ferric chloride, then oxidated with 5% potassium permanganate. Gold in the solution was adsorbed twice by carbon-loaded foam plastic. The carbon-loaded foam plastic with gold was burned at 580℃ and dissolved in 50% aqua regia, after which the content of gold could be measured by ICP-OES. The detection limit is 0.002 μg/g and precision (RSD, n=11) is less than 3.7%. The method of gold adsorption rate is greater than 99.9% and the measured range is 0.01-90 μg/g. The method has a strong adaptability to different types of gold ore with higher accuracy for low content and high content of the samples than the previous method.