Donaldson E M, Charette D J, Rolko V H
Mineral Sciences Division, Department of Energy, Mines and Resources, Mines Branch, Ottawa 4, Ontario, Canada.
Talanta. 1969 Sep;16(9):1305-10. doi: 10.1016/0039-9140(69)80006-8.
A method for determining 0.0005-0.05% of cobalt and zinc in high-purity niobium, tantalum, molybdenum and tungsten metals by atomic-absorption spectrophotometry is described. After sample dissolution, cobalt and zinc are separated simultaneously from the matrix materials by chloroform extraction of their thiocyanatediantipyrylmethane ion-association complexes, at pH 3.25, from a citric acid medium approximately 1.2M in sodium thiocyanate. Interference from copper is eliminated with thiourea. Large amounts of iron interfere under the recommended conditions, but moderate amounts may be present in the sample solution without causing appreciable error in the results. Phosphorus (as orthophosphate) interferes in the extraction of cobalt from tungsten solutions. Moderate amounts of other impurities do not interfere in the proposed method.
描述了一种用原子吸收分光光度法测定高纯铌、钽、钼和钨金属中0.0005 - 0.05%钴和锌的方法。样品溶解后，在pH 3.25的条件下，从硫氰酸钠浓度约为1.2M的柠檬酸介质中，通过氯仿萃取钴和锌的硫氰酸二安替比林甲烷离子缔合物，将钴和锌与基体材料同时分离。用硫脲消除铜的干扰。在推荐条件下，大量铁会产生干扰，但样品溶液中存在适量铁时，不会导致结果出现明显误差。磷（以正磷酸盐形式）会干扰从钨溶液中萃取钴。适量的其他杂质不会干扰所提出的方法。
