187Re-187Os Calibration of Molybdenite from Henderson, Colorado: A New NIST Reference Material

0111876 Stein基于铼（Re）衰变为锇（Os）的地质年代计的使用正在迅速扩大，并且没有国家标准与技术研究所（NIST）认证的参考材料用于实验室间的比较。 化学和质谱方法的进步允许高精度测定Re和Os，即使在低ppt水平的样品。 辉钼矿（MoS 2）特别适合用于Re-Os计时器，因为它通常含有高浓度的母Re，基本上不含初始子体Os。因此，即使在非常年轻的样品中，187 Re衰变为187 Os也能产生精确的年龄，而无需对初始Os进行校正。需要一种可接受的参考材料用于实验室间的比较，这一点已变得至关重要。 我们建议与阿尔伯塔大学和NIST合作，校准铼-锇铍钇矿标准物质。 建议的Re-Os参比辉锑铅矿来自科罗拉多的亨德森，该位置是一个研究充分的钼存款。 NIST将对亨德森镁铝石粉末进行物理混合、拆分和装瓶。 将由科罗拉多州立大学的AIRIE实验室和阿尔伯塔大学的同位素实验室对具有统计学代表性的样本集进行分析。 参考材料的分发将完全由NIST负责，并且钙钛矿参考材料的成本将仅反映NIST在其工作部分中产生的成本。 ***

0111876SteinUse of the geochronometer based on the decay of rhenium (Re) to osmium (Os) is rapidly expanding, and there are no reference materials certified by the National Institute of Standards and Technology (NIST) for inter-laboratory comparison. Advances in chemical and mass spectrometric procedures permit high precision determination of Re and Os, even on low-ppt level samples. Molybdenite (MoS2) is uniquely suited for the Re-Os chronometer because it commonly contains high concentrations of the parent Re and essentially no initial daughter Os. Thus, the decay of 187Re to 187Os yields precise ages, even in very young samples, without correction for initial Os. With increasing demand for Re-Os dating, particularly of molybdenite, the need for an accepted reference material for inter-laboratory comparison has become crucial. We propose to calibrate a Re-Os molybdenite reference material, working together with University of Alberta and NIST. The proposed Re-Os reference molybdenite is from Henderson, Colorado, the location of a well-studied molybdenum deposit. NIST will physically mix, split, and bottle the Henderson molybdenite powder. Statistically representative sets of samples will be analyzed by the AIRIE Lab at Colorado State University and by the isotope lab at the University of Alberta. The distribution of the reference material will be fully handled by NIST, and the cost for the molybdenite reference material will reflect only the costs incurred by NIST for their part of the work. ***