Preparation of SF6 for sulfur isotope analysis by laser heating sulfide minerals in the presence of F2 gas
Preparation of SF6 for sulfur isotope analysis by laser heating sulfide minerals in the presence of F2 gas
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DOI：
10.1016/0016-7037(93)90499-m
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发表时间：
1993-09
影响因子：
5
通讯作者：
D. Rumble;T. Hoering;J. Palin
中科院分区：
文献类型：
--
作者：
D. Rumble;T. Hoering;J. Palin
本文论证了硫化物矿物原位吸附法进行硫同位素分析的可行性。粉末样品的激光扫描，以前分析的传统散装SO2或BrF 5的方法，验证了可比的精度和准确度，可以实现与新的方法。粉末样品的δ 34 SCDT和δ 33 SCDT值在15 ~ 120 ℃范围内与F2气压无关。此外，对于在室温下不自发氟化的粉末，δ 34 SCDT值与SF6产率无关，从40%到100%。粉末状黄铁矿、硫铁矿、黄铜矿、闪锌矿、方铅矿、针铁矿和绿硫铁矿的重复分析精度通常为0.1-0.2‰。在δ 34 SCDT从−30到+34‰的范围内，先前分析的粉末的实验室间比较接近0.1‰，不一致高达0.8‰。通过对硫化物矿物抛光表面激光坑和钻孔粉末的对比分析，验证了原位激光抛光技术的有效性。对于同位素均匀的样品，激光陨石坑和钻孔粉末的δ 34 SCdt和δ 33 SCDT都在0.1-0.3‰之间，这取决于所分析的矿物。
The feasibility of in-situ fluorination of sulfide minerals for sulfur isotope analyses has been demonstrated. Laser fluorination of powdered samples, previously analyzed by conventional bulk SO2or BrF5methods, verifies that comparable precision and accuracy can be achieved with the new method. Theδ34SCDTandδ33SCDTvalues of powdered samples are independent of F2gas pressure over a range of from 15 to 120 torr. Furthermore,δ34SCDTvalues are independent of SF6yields from 40 to 100% for powders that do not fluorinate spontaneously at room temperature. The precision of replicate analyses of powdered pyrite, troilite, chalcopyrite, sphalerite, galena, acanthite, and greenockite is typically 0.1–0.2‰. Interlaboratory comparisons of previously analyzed powders agree as closely as 0.1‰ and disagree by as much as 0.8‰ over a range ofδ34SCDTfrom −30 to +34‰. The technique of in-situ laser fluorination was validated by comparison of analyses of side-by-side laser craters and powders from drill holes in polished sulfide mineral surfaces. For isotopically homogeneous samples, laser craters and drill hole powders agree within 0.1–0.3‰ for bothδ34SCdtandδ33SCDT, depending on the mineral analyzed.