Simultaneous Determination of Au and Associated Elements Ag, Cu, Pb, Zn, As and Sb in Gold Ore by ICP-MS with Hypochloric Acid Oxidation

Abstract

Gold ore contains a certain amount of gold, silver, copper, lead, zinc, arsenic, and antimony. Gold needs to be determined after roasting, digestion and enrichment; arsenic and antimony are lost after roasting, while silver, copper, lead, zinc, arsenic and antimony need to be separately determined, which is extremely cumbersome. The experiment utilized the oxidizing properties of hypochlorous acid to oxidize carbonaceous materials and sulfides in a nitric acid medium instead of sample roasting. Combined with offline internal standards, a method was established for the simultaneous determination of gold, silver, copper, lead, zinc, arsenic, and antimony by ICP-MS. The amount of hypochlorous acid, digestion time, internal standard selection, and interfering elements were optimized. The results showed that the carbonaceous and sulfides materials were oxidized under the conditions of 10.0000g of the sample, 20mL of nitric acid and 5mL of hypochlorous acid with using a heating plate to deal with them until near-dryness. According to the experimental method, gold, silver, copper, lead, zinc, arsenic, and antimony were determined in five different types of gold ore samples, the results were consistent with the national standard method, and the relative standard deviations (RSDs, n=7) were less than 4.71%. This method solves the problem of simultaneous determination of gold, silver, copper, lead, zinc, arsenic and antimony, which is simple and convenient. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202403130044.

Keywords

• hypochloric acid
• inductively coupled plasma-mass spectrometry
• gold ore
• gold
• associated elements