This study describes an improved alkaline fusion technique for the Re–Os dating of molybdenite. The molybdenite sample was digested in a zirconium crucible with NaOH and carbonized flour at 700 °C. The flour can reduce Os from a high oxidation state to a lower oxidation state during the high-temperature digestion so that isotope equilibration can be reached between the spike and the sample. Less amount of NaOH was used compared with the previously reported technique, lowering the procedure blank. Rhenium was separated by kinetic absorption with an anion exchange resin, and Os was purified by distillation with aqua regia and H₂O₂. Both Re and Os isotope compositions were measured via inductively coupled plasma mass spectrometry. The results obtained for the molybdenite reference material, JDC, were in good agreement with certified values, demonstrating that the proposed method is efficient for the Re–Os dating of molybdenite. Compared with Carius tube and high-pressure asher sealed acid digestion methods, the improved alkaline fusion method yields comparable Os blanks but has a more simple, quick, and secure procedure.

中文翻译：

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辉钼矿通过改进的碱熔法进行Re-Os定年

这项研究描述了一种改进的碱熔技术，用于辉钼矿的Re-Os定年。在700°C下，用NaOH和碳化的面粉在锆坩埚中消解辉钼矿样品。面粉可以在高温消化过程中将Os从高氧化态还原为低氧化态，从而使加标物和样品之间达到同位素平衡。与先前报道的技术相比，使用的NaOH量更少，从而减少了空白步骤。通过用阴离子交换树脂进行动力学吸收来分离separated，并通过与王水和H ₂ O ₂蒸馏来纯化Os 。Re和Os同位素组成均通过电感耦合等离子体质谱法。辉钼矿参考材料JDC的结果与认证值高度吻合，表明所提出的方法对于辉钼矿的Re-Os定年是有效的。与Carius管和高压灰烬密封酸消解方法相比，改进的碱熔法可产生可比的Os坯料，但过程更简单，快速且安全。