Geochemistry of bedrock and glacial deposits in the vicinity of the Bend massive sulfide deposit, north central Wisconsin

Abstract

Summary of XRAL Geochemical Techniques Atomic Absorption Spectrophotometry (AAS) Antimony (Sb), arsenic (As), selenium (Se), tellurium (Te) and thallium (Tl) were all analyzed by hydride generation atomic absorption spectrophotometric techniques. For arsenic and antimony, samples are mixed with sodium peroxide and heated in a muffle furnace set at 750°C for four minutes. The sample is cooled then 15 ml of water and 5 ml of concentrated HCl is added. The mixture is shaken and 0.25 ml of an ascorbic acid KI solution is added then diluted with 20% HCl and let to stand overnight. The lower detection limit for both As and Sb is 0.6 ppm. Selenium and tellurium are determined by adding the sample to a mixture of nitric, hydrofluoric and perchloric acids and heating. After the solution is cooled hydrochloric and nitric are added, heated again and cooled, after which the sample is analyzed. The lower detection limit for Se is 0.2 ppm and for Te is 0.1 ppm. Thallium is determined by weighing 0.1g of sample into a zirconium crucible. Approximately 0.75g of sodium peroxide is added and mixed. The mixture is heated in a muffle furnace set at 750°C for four minutes. The sample is cooled then 15 ml of water and 5 ml of concentrated HCl is added. The mixture is shaken and 0.25 ml of an ascorbic acid KI solution is added then diluted with 20% HCl and let to stand overnight before analysis. The lower detection limit for Tl is 0.1 ppm.