Donaldson E M, Wang M
Mineral Sciences Laboratories, Canada Centre for Mineral and Energy Technology, Department of Energy, Mines and Resources, Ottawa, Canada.
Talanta. 1986 Mar;33(3):233-42. doi: 10.1016/0039-9140(86)80057-1.
Methods for determining ~ 0.2 mug g or more of silver and cadmium, ~ 0.5 mug g or more of copper and ~ 5 mug g or more of antimony, bismuth and indium in ores, concentrates and related materials are described. After sample decomposition and recovery of antimony and bismuth retained by lead and calcium sulphates, by co-precipitation with hydrous ferric oxide at pH 6.20 +/- 0.05, iron(III) is reduced to iron(II) with ascorbic acid, and antimony, bismuth, copper, cadmium and indium are separated from the remaining matrix elements by a single methyl isobutyl ketone extraction of their iodides from ~2M sulphuric acid-0.1M potassium iodide. The extract is washed with a sulphuric acid-potassium iodide solution of the same composition to remove residual iron and co-extracted zinc, and the extracted elements are stripped from the extract with 20% v v nitric acid-20% v v hydrogen peroxide. Alternatively, after the removal of lead sulphate by filtration, silver, copper, cadmium and indium can be extracted under the same conditions and stripped with 40% v v nitric acid-25% v v hydrochloric acid. The strip solutions are treated with sulphuric and perchloric acids and ultimately evaporated to dry ness. The individual elements are determined in a 24% v v hydrochloric acid medium containing 1000 mug of potassium per ml by atomic-absorption spectrophotometry with an air-acetylene flame. Tin, arsenic and molybdenum are not co-extracted under the conditions above. Results obtained for silver, antimony, bismuth and indium in some Canadian certified reference materials by these methods are compared with those obtained earlier by previously published methods.
本文描述了测定矿石、精矿及相关物料中银和镉含量≥0.2μg/g、铜含量≥0.5μg/g以及锑、铋和铟含量≥5μg/g的方法。在样品分解并回收被硫酸铅和硫酸钙保留的锑和铋后，于pH 6.20±0.05条件下通过与水合氧化铁共沉淀，用抗坏血酸将铁(III)还原为铁(II)，然后在约2M硫酸 - 0.1M碘化钾溶液中通过甲基异丁基酮单次萃取碘化物，将锑、铋、铜、镉和铟与其余基体元素分离。萃取液用相同组成的硫酸 - 碘化钾溶液洗涤以除去残留的铁和共萃取的锌，并用20%（v/v）硝酸 - 20%（v/v）过氧化氢从萃取液中反萃取被萃取的元素。或者，在通过过滤除去硫酸铅后，银、铜、镉和铟可在相同条件下萃取并用40%（v/v）硝酸 - 25%（v/v）盐酸反萃取。反萃取液用硫酸和高氯酸处理，最终蒸发至干。通过空气 - 乙炔火焰原子吸收光谱法在每毫升含1000μg钾的24%（v/v）盐酸介质中测定各元素。在上述条件下，锡、砷和钼不会被共萃取。将这些方法应用于一些加拿大标准参考物质中银、锑、铋和铟的测定结果，与之前发表的方法所获得的结果进行了比较。
